Monday, December 31, 2007

First Week of 2008

Well it's the last day of 2007 -- wow -- time sure does fly.

It looks like 2008 will arrive on the chilly side for much of the nation. It will be snowy from the Great Lakes into New England.

With the exception of a new storm moving onshore in the west, most of us should be sunny and dry this week.

It will be windy at times, especially from the Rocky Mountains into the center of the country. (Texas up to Minnesota)

The weather will turn a bit more active heading into the first full weekend of 2008.

Portions of the south are finally seeing some decent rainfall. Some sections of Alabama recorded over 3 inches of rain this past weekend.

About a half dozen stations have seen 4 to 5 inches of rain since Christmas.

Did you know you can pull a precipitation summary for your state, and even your county?

From the CoCoRaHS website, click on View Data at the top of the page. Once that loads, scroll down to "Total Precipitation Summary" -- which is under the Summary Reports section.

Then, click it and select your state. If you want, you can zoom down to your county.

As a test, pick Alabama and then Dale County (DL). Choose the date range of December 1 through December 31.

There are 4 stations in that county and all have seen some really generous moisture from Mother Nature.

Friday, December 28, 2007

Rain, Snow Moves East

If you can't reach your dear friends in Alabama today, don't worry -- they are probably out dancing in the rain.

Yes, bama saw some of the best rain in months over the past 24 hours. A few CoCoRaHS stations in east-central Alabama recorded over an inch.

I would venture a guess that was the first time those gauges have had an overflow in quite some time -- maybe since joining the network!

Portions of central Tennesee also saw rainfall. That rain will shift east along with the cold front today.

Hail and strong to severe thnuderstorms were also reported over the past 24 hours in the deep south. Stations near Muscle Shoals and Tuscumbia (Ala.) reported hail around 4 am Friday morning.

Here in the Denver area we have sunny skies and PLENTY of snow to shovel around. It is a whopping 1 degree in Southeast Aurora as I blog with 14 inches of powder on the ground. That has fallen since Christmas morning.

BRRRR --- off to make some hot tea!

Thursday, December 27, 2007

New Winter Storm Moving In

Well after 8 inches of fresh snow on Christmas, we are bracing for another round today along the Front Range of the Rockies.

It is cold too -- just 10 degrees as I blog and watch the snow pile up on my freshly shoveled drive.

Hey, I will hush -- this time last year we couldn't find enough places to shovel the snow after back-to-back storms dropped up to 4 feet on Denver.

If you are traveling home anywhere across the center of the nation over the next day or so, the weather will be a factor.

Our Colorado storm will pull east with plenty of rain, snow, wind and fog.

Some good news! The storm system should tap the Gulf of Mexico and bring moisture back into the southeast states -- EXCELLENT news for the drought.

And looking ahead, arctic air currently building over Canada will break loose and move into the northern plains as we head into the first few days of January.

Just how cold and how much real estate it will cover remains to be seen. But some places may only see highs in the single digits near the US/Canadian border next week.

Wednesday, December 26, 2007

I'm Back, And Caught Up On My Reports

Hello fellow CoCoRaHS'ians --

Well another Christmas season in retail has come and gone, it nearly killed me this year. (Just Joking)

Although now it is gift card season, and stores will be busy for the next 2 weeks with bargain hunters wanting to spend that Christmas money.

It was hard to keep up with CoCoRaHS -- in fact I just sat down and did a little catch-up data entry.

I entered all the data for my station since December 5.

I want you to know if you get into a jam and life becomes hectic, it is OK to make notes of your data somewhere and do the data-entry when you have time.

I have to be honest, I forced myself to sit down and catch up today because I knew if I didn't I would eventually lose the paper with my data on it.

So what has been happening of late? TONS of winter storms have moved across the nation. I don't think the winter has been this active across so much real estate for quite some time.

We had a lovely snow in the Denver area yesterday, to the tune of 4 to 8 inches around most of the metro. More is on the way tomorrow.

And parts of the parched southeast FINALLY saw a decent, widespread rainfall. Though not nearly enough to put a dent in the drought, it is a start.

Don't forget to leave your questions or comments if you have any -- I enjoy reading them and often they spark my brain to come up with my next blog entry.

Tuesday, December 18, 2007

More Winter To Come

A new series of storm systems will make their way across the country over the next 5 to 7 days.

One is looking like it could be a decent storm developing over the middle of the nation by this weekend.

For us here in the Front Range of Colorado, it is bitter sweet. We need the moisture, but it was about this time last year when we got hit with the first of twin holiday blizzards that shut down the region.

Winter officially arrives around 1 am eastern time on Dec. 22 this year.

So much can change with the forecast so we'll have to see how this evolves.

Wednesday, December 12, 2007

Ice Storm Leaves Tremendous Damage

Our CoCoRaHS friends in the center of the nation are starting to thaw out -- what an ice storm!

I have to tell you, growing up in Arkansas and living through many ice storms, well -- it really stinks. You are literally trapped. Life stops.

It can also be downright creepy once you lose power. There are so many sounds -- trees creaking, limbs snapping, power lines popping and transformers blowing -- it makes it hard to sleep.

I was home for Christmas about 5 or 6 years ago when an ice storm hit. A pine tree fell on our house and we had to evacuate to another relative's home. It took over an hour to drive less than 3 miles on country roads.

I hope you are all safe and as life gets back to normal and you can file a CoCoRaHS report again -- when you do so, feel free to leave a detailed comment in your first report about your experience during the storm, damage in your area, etc..

The information will be great to archive for your station.

In a recent comment, an observer from Kansas asked about reporting a trace or zero when you have dew.

Dew is not precipitation because it forms at the surface and does not fall from the sky. It is a completely different process than precipitation.

Therefore you would report zero when you have dew in the morning. If you like, you can definitely note that there was dew in your comments.

A simple comment like "heavy dew this morning" tells a meteorologist something about the weather at your location. I would conclude it was moist, the temperature and dewpoint were very close together if not equal -- and perhaps something was on the weather map in your location such as a warm front.

Hope that helps -- keep the comments coming. I do my very best to read each and every one, and try to answer them too. I remain very busy with work right now so bare with me on my response time.

Monday, December 10, 2007

Winter Blasts Center of Nation For Second Time

It was a cold and wintry weekend for many of the central states, with several inches of snow in Denver to over an inch of ice in southwest Missouri. Wintry precipitation also fell across portions of New England. This was all due to a huge cold front that draped across the country.

The town of Lamar, Missouri was completely without power Monday morning.

Meanwhile, portions of the south are wondering what happened to the date -- as it feels like September or early October. Highs from Texas to North Carolina and Georgia have been well into the 70s with a few 80s.

Round 2 of the wintry weather is coming tonight into Tuesday and Wednesday. It promises more snow for Denver and ice from Oklahoma and Kansas into Missouri and Illinois.

The freezing rain makes for tough measurements in a CoCoRaHS world. You should have the inner cylinder and funnel removed from your gauge anytime you are expecting wintry precipitation.

At your observation time, bring the cylinder in and let the contents melt.

It really helps to have 2 gauges because you can simply take the gauge off and replace it with the new one at your observation time.

I do that here in Colorado when I am pressed for time in the morning -- I bring the gauge with the frozen precipitation inside and put the funnel on it as a lid, and let the contents melt during the day. When I get home from work I will measure and report the precip.

It is OK to make it easy on yourself. You can always go back and do the data entry for your location if the morning is rushed and you are pressed for time.

The most important thing is to just make the observation, especially if it is precipitating at your time of observation.

Thursday, December 6, 2007

Blizzard Warning In Hawaii

Yes, that is right -- you read this headline correctly.

Mauna Loa and Mauna Kea above 8,000 feet have been under a blizzard warning for the past several hours with temperatures in the 20s and moderate to heavy snow from passing squalls.

Down at the lower elevations, heavy rain has been falling on the big island of Hawaii -- prompting flash flood warnings.

A new storm is about to sweep into southern California with some much needed rain. As the storm moves east it will draw down some cold air and produce winter precipitation in the middle of the nation this weekend.

Monday, December 3, 2007

Reporting a Trace

Someone left a comment recently asking about a TRACE. See question below.

QUESTION: "Would you please clarify the use of "T" for trace. My reporting time is 7:00 AM, however if I know that a trace occured 4 hours prior to my reporting time do I still enter "T" under the precipatation block, then clarify the actual time of the trace in the Obervation Notes section?"

ANSWER: If your reporting time is 7 am, you are reporting anything that happened at your station up until the observation time. So if a trace happened overnight, or even at 6:59 am, you will report a T for trace.

Another way to think of it is that you are reporting anything during the past 24 hours, or since your last observation was made at 7 am yesterday.

If you would like to leave more information (such as the time it happened) you can certainly do so in the notes.

Thanks for reading the blog and asking such great questions!

Saturday, December 1, 2007

Weather Folklore

Today I was driving down the road and we had a little shower/freezing drizzle in the Denver area -- and at the same time the sun was shining. It made for a beautiful rainbow.

Growing up in the south, we would say that if it rains and the sun shines at the same time, it will rain the same time again tomorrow.

There is no meteorological truth to that, and most likely that is said because you tend to get afternoon showers and thunderstorms during the warm season in the southeast states just about the same time each afternoon when a humid, hot airmass is in place.

But nonetheless, it is interesting.

Do you know any weather folklore? If so, share it with us.

Thursday, November 29, 2007

What Is The Best Outdoor Thermometer?

I really love these questions you all have been leaving in the comments.

Yesterday an observer asked if there is a preferred type of thermometer for using to gather high and low weather data?

My honest answer isn't that there is a preferred type, but use a lot of care when setting up the instrument so that you are getting a true sample of the air temperature.

For example -- if your instrument is too close to a house, shed, deck, etc. it will potentially read warmer than the air temperature from the heat retained in the brick or wood.

Likewise, if it has too much sun exposure it could read higher during the daytime than it really is. You see this a lot on bank signs for example.

Most weather stations you can buy have the temperature sensor in a solar shield I believe.

WWW.AMBIENTWEATHER.COM is a good website to use for researching weather stations.

Wednesday, November 28, 2007

Reporting Weather Data -- Highs, Lows, etc.

A CoCoRaHS observer left a comment on my post yesterday asking a few questions.

1. How do you make the degree symbol without typing the word? Hold the ALT key on your keyboard and enter the numbers 0186. (this is windows -- not sure about other systems)

2. How do you report other weather data (like highs and lows) to CoCoRaHS? The data entry page on CoCoRaHS only lets you enter precip. At one point there was some discussion about adding a place to enter highs, lows, etc. for your weather station.
Not sure if or when that day will come -- so at the present, you can leave the information in the comments section and it will archive with all your reports.

Great questions! It is very cold today across much of the northern US -- here in Denver it is very windy to boot! Bundle up if you are in these locations.

Tuesday, November 27, 2007

Sub-Zero Temps

Well hello -- it has been a while. I am really sorry, but I just have a lot on my plate with the holidays here.

I work for Phillips-Van Heusen as a field marketing rep. in Colorado, so I am spending almost every minute of the day in either JCPenney, Macys or Dillards -- making sure our product is presented well for the holidays.

Luckily I was off the day after Thanksgiving to recover from all the food!

Anyway -- I see some minus temps on the map this morning across northern Minnesota and North Dakota.

The northern tier of states will stay chilly over the next several days and see occasional chances for snow showers as two weather fronts move through.

Portions of the south saw some rain on Monday -- but not nearly enough to put a dent in the drought.

Monday, November 19, 2007

Chilly Holiday Week Forecast

Sorry it has been a few days since I last posted -- this is a busy time of year for my job in the retail world.

I just took a quick look at some weather data and it looks like the entire lower 48 will get in on a major cold front over the next several days.

By the weekend, much of the nation will see highs in the 50s or lower, even as far south as the Gulf Coast.

Only southern Florida looks like it will hold onto 70 degree or higher temps for daytime maximums.

For the middle of the country and locations along the US/Canada border, highs in the 20s to 40s will be the rule over the next week with occasional snow showers possible.

There could even be a rain/snow mix as far south as central Missouri by the Turkey Day!

Wednesday, November 14, 2007

Another Cold Front

Another cold front is sweeping across the country today. Here in Denver we are getting much cooler weather and some light rain and snow showers in a few places.

It has been really windy this week for many people. Hurricane force gusts have been recorded in the northwest US.

High wind warnings and wind advisories are in effect for portions of the high plains today where gusts up to 60 mph are possible.

In portions of the southeast and along the Gulf Coast of Texas you woke up to dense fog this morning.

Monday, November 12, 2007

Active Weather Pattern Ahead

A series of storm systems will move onshore in the Pacific Northwest this week, bringing plenty of rain, wind and snow to Washington and Oregon.

These fronts will move across the lower 48 states, keeping the weather unsettled. Here in Denver, we are expecting a roller coaster ride in temperatures. Highs on Sunday were around 70, we'll be in the 40s today, back to near 70 Tuesday and back to the 40s on Wednesday.

I suspect many people will catch cold from the temperature fluctuation.

The southern states have been extremely warm, esp. from Arizona to Texas. Some cooler weather should make it south by the week's end.

Wednesday, November 7, 2007

What Is Average, Or Normal?

When you see the average high for a date in your community (or normal high) do you know where that data comes from?

The same applies to average precipitation or snowfall.

Climatological averages are calculated from 30 years of data. Currently, average highs and lows are calculated from weather records between 1971-2000.

They are recalculated every 10 years using the previous 30 years worth of data.

So in 2011 the average high and low for your area will come from 1981-2010.

Now don't confuse this with record highs, lows, rain or snow for your area. A record is over the entire climate record.

So if weather data has been collected since the 1800s where you live, the entire record is examined to determine when a new record is achieved.

This is a point of debate in some places where the weather station has moved. Here in Denver for example, our official weather station moved approximately 30 miles northeast of downtown Denver with the new airport in the 1990s.

Many people don't like when a new record is set for the city because the airport's location isn't representative of where people live.

Well -- for climate purposes, even if a weather station moves, it is still continued one continuous climate record. And the simple fact of that is that documenting weather data is still a new science. Most stations have only been around 100 or so years now.

If we didn't compare the current weather to what we have documented before the weather station moved, what would we use for a comparison? The answer is nothing -- because there were no weather records kept prior.

So remember -- average or normal highs, lows, rain or snow can change every 10 years because these parameters are recalculated.

But records are compared to the entire climate history available for a station, even if it has changed location within a city. There is probably always room for an exception and I cannot immediately think of one, but I wanted to say that just in case. ;-)

Tuesday, November 6, 2007

Baby It's Cold Outside

Reading through this morning's daily comment reports made me want to reach for a warm cup of cocoa!

From frost reports here in Colorado to frozen birdbaths in Indiana -- it's really cooling down across the nation.

Lake effect snows are flying across the UP of Michigan and extreme northern Wisconsin today -- as well as in the lake effect snow belts of New York and northwest PA.

Snow flurries have even been seen at times across Iowa.

In the south, a slew of frost and freeze warnings are in effect across Dixie.

It's bone dry here in the west and in the south too -- one observer from Alabama filed their 12th report since signing on with CoCoRaHS and they have all been 0. Come on Mother Nature -- at least give him or her a TRACE to reoprt!! ;-)

As fun as precipitation is, your zero is also very important data. So keep the reports coming and the great comments too!

Monday, November 5, 2007

1st Winter Blast Of Season Moving In

A major cold front is moving south from Canada today -- it will bring the biggest taste of winter that we have seen so far this season.

Lake effect snows are expected from Duluth to Chicago. In the southern Great Lakes it will be mostly a sprinkle/flurry event with perhaps some minor accumulations.

Further north, a few inches are expected on the south shore of Lake Superior.

The front will sweep into Dixie this week with highs in Nashville, Tennessee tumbling into the 50s by midweek.

Even the Gulf Coast will see a cool down with highs in the 60s across the Florida panhandle by Wednesday.

In my last blog entry I asked for tips on cleaning the inner tube of our rain gauges. There were several good comments. One even tells you how to use a chop stick to clean!!

Here in the snow country of the west, we are just putting the outer cylinder out until spring. We have to be prepared for snow at anytime from now until April.

Those in the Great Lakes and New England should be almost ready to convert over to the winter setup (just the out cylinder and snow board). Be sure to find your snow stick or yard stick so you can measure the first snow!! And don't forget where you stored the funnel and inner tube -- sometimes when we go 2 or 3 weeks without precip it can get lost in the house or garage! (That has NEVER happened to me ;-) by the way!)

Friday, November 2, 2007

Noel Update, Cleaning Your Gauge

Hurricane Noel continues to head north in the Atlantic. The storm isn't necessarily growing in strength but is growing in size.

It may impact portions of the east coast and New England states with rain later this week.

Meanwhile, the damage has been done in Cuba, Haiti and the Dominican Republic. Over 100 have died and several more are missing.

A dam broke in Cuba flooding homes and crops.

An observer left a comment on the blog the other day saying they have to clean the gauge frequently due to pollen and dust.

Yes! Depending on where you live the problem is going to be worse than other places.

Does anyone have a helpful method or tip for gauge cleaning? If so, leave a comment on the blog and share it with all of us.

Wednesday, October 31, 2007

Wintry Weather Showing Up On Maps

Well, it's that time of year for more and more of the country. Here in Colorado, we have already seen wintry weather a few times since late September, but that is normal for us.

Now wintry weather is showing up in places like upstate New York.

There were several reports from Monday of sleet and a few flakes of snow as showers moved off Lake Ontario.

In addition, the first killing freeze hit the area putting an end to the growing season across portions of the northeast.

Before too long, we'll see the first winter storm of the year move across the northern tier of the US -- November is fair game for this.

Tropical Storm Noel continues to ravage Hispanola. Nearly 2 dozen have died from the heavy rain and flash flooding/mudslides.

South Florida is still on alert as this slow moving storm churns erratically to the north.

Tuesday, October 30, 2007

Noel Update; Welcome Alabama, Kentucky

Tropical Storm Noel is moving over western Cuba and is dropping extremely heavy rainfall over Hispanola.

The storm has been moving a bit further west than previously anticipated, which means once it emerges over water and takes a northerly turn, it could graze south Florida over the next 48 hours.

We'll wait and see.

There are about a dozen or so CoCoRaHS observers along the southeast Florida coast so if Noel does move in, we should see some great precipitation data.

Meanwhile, speaking of data, we are now getting reports from both Alabama and Kentcuky. Welcome observers!

The weather is quiet nationwide, with most reporting stations dry yesterday and today. That is actually pretty typical of this time of the year, but it won't be long before the jet stream arrives in the US and hangs around for several weeks, bringing active winter weather, including the wet season to southern California.

It is getting cooler and cooler with each passing day. I noticed there were frost and freeze advisories scattered around the nation this morning, including across portions of Tennessee and North Carolina.

Monday, October 29, 2007

Tropical Storm Noel Forms in Carribbean

Tropical Storm Noel formed over the weekend from an area of disturbed weather south of Hispanola.

The storm peaked with winds gusting over 50 mph late Sunday, but now are dropping back a bit as the center moves over land.

Although minimal in terms of winds, this storm is going to drop life-threatening rainfall over Haiti and the island of Hispanola.

Some places could see 10 to 20 inches of rain with isolated amounts up to 30 inches.

Due to the mountainous terrain, mudslides are likely.

I am sure Noel will make a few headlines over the next day or so.

The storm is expected to move north toward the Bahamas, but current forecasts suggest it will curve eastward away from Florida and the USA.

In some aspects it'd be nice if Noel could stay minimal but move into the southeast United States because they so desperately need the rain.

Wednesday, October 24, 2007

US Weather Summary

Rain and unsettled weather will continue across the southeast states today. Some locations in the drought stricken states of Alabama, Georgia and Tennessee have seen 2 days in a row with rainfall.

Meanwhile, a new storm system is set to come onshore in the Pacific Northwest in the next 24 hours.

It will sweep across the country over the weekend and into early next week with cooler weather and some precipitation.

In southern California, winds are slowly weakening and the humidity is coming up -- GREAT news for the fire fighters!

There are unfortunately still several days of fire fighting ahead -- but at least conditions are showing signs of improvement -- which is the best news we have heard in several days.

Tuesday, October 23, 2007

Skies Open In Drought Plagued Areas

My goodness -- today's CoCoRaHS reports must be some kind of record. I'll have to email Nolan to ask.

There were just over 350 reports of 1.00" or more as of 10:30 am MDT today -- 356 to be exact.

And what is so wonderful is many of those reports are from Tennessee and Alabama.

In fact, 216 of those reports were from Tennessee alone! Rain gauges were hard at work on Monday and that is a GOOD THING for this drought stricken state.

Two stations in Montgomery County picked up over 6.00 inches of rain yesterday, and one in Humphreys did too.

One observer in Davidson County, Tennessee said it best in the daily comment reports --- WHOOPEE!!!

Another observer near Spring Hill, Tennessee said there is water in the pond again -- my goodness that is great news.

Monday, October 22, 2007

Much Needed Rain Heading For The S.E. States

Good morning from a chilly Octo - brrrrrrr morning in Denver. Lows here ranged from 20 degrees over the southeast metro where the most snow fell to about 27 degrees downtown and out at the international airport.

I was just looking at the forecast for some southern cities, including Atlanta, Little Rock, Memphis, Birmingham and Mobile.

They all have a 100% chance of rain and thunderstorms in the forecast!! This is excellent news for these drought stricken locations.

I am not sure how much of a chance you get to follow the news, but some of these areas are close to just having a few months of water supply left, according to reports.

It will take days of rain to put a dent in the drought there, but at this point -- every single drop counts!!

One area that is expecting heavy rain, but doesn't need it, is the Pensacola area. Just last week they saw up to 12 inches of rain.

It will be interesting to watch the CoCoRaHS maps for both Florida and Tennessee over the next few days.

Alabama will be coming online soon enough -- I believe November 1.

Sunday, October 21, 2007

Fall In The Rockies

Fall in the Rockies means rapidly changing weather, in addition to other things like the beautiful changing aspen, hibernating bears, etc.

Less than 24 hours ago I was riding my bike around a suburban Denver metro area park enjoying a high of 80 degrees.

Now I am sitting at my computer on Sunday morning watching it snow outside.

The snow in Denver is almost right on time -- our average first snow falls on October 19. Today is the 21st.

The beauty is it will be leave almost as fast as it came with sunny skies and a return into the 50s by tomorrow.

My family in Arkansas says oh my gosh, how do you deal with that. We'd be stuck in the house, maybe for a few days!! It's true, just mention the word flurry in the forecast there and the store's shelves go bare. ;-)

Friday, October 19, 2007

Skies Open Over NW Florida

Wow-we-wow! Did you see the Florida maps today?

Not only did a tornado touch down on Thursday and move right through downtown Pensacola, but heavy rains hammered the region too.

Over a dozen stations picked up over a half-foot of rain on Thursday, with station FL-ES-2 recording a whopping 12.10 inches of rain for the observation period.

That is more than an entire year's worth of rain for many locations here in the interior west!

Elsewhere, it was an active day for severe weather once again. Hail hammered the Chicagoland area during rush hour and tornadoes moved through portions of Michigan and Kentucky.

Thursday, October 18, 2007

Nice Job CoCoRaHS Observers

WOW -- there were several intense precipitation reports filed on Wednesday from the midwestern states. GREAT JOB!

One Missouri station saw almost an inch of rain in just 15 minutes!

As I am writing this blog at 1:04 am Thursday, the radar is lit up like a Christmas tree in the Ohio River Valley -- I bet there are some rain gauges in Illinois and Indiana overflowing into the outer cylinder even as I type!

I wish I were there.

Wednesday was a violent day with severe weather -- nearly 200 reports of hail and wind. There was over a dozen tornadoes, with the most touchdowns in southwest Missouri. Damage was reported in and around the Springfield vicinity.

2.5" hail fell near Medicine Lodge, Kansas.

74 mph winds screamed through Muskogee, Oklahoma.

More severe weather is expected today in the Ohio River Valley.

On the backside of the storm system, highs winds and chilly temperatures can be found in the Rockies, along with some snow along the Continental Divide of the Rockies.

Wednesday, October 17, 2007

Fall Severe Weather Outbreak

WOW! Take a look at the regional surface map for the southern plains today. (the link is down in yesterday's blog entry)

Southeast winds have transported copious amounts of moisture into the southern plains. Dewpoint temperatures (a measure of the moisture available) are in the upper 60s to middle 70s.

Above the ground at jet stream level, winds are blowing out of the southwest as a storm system moves in along with a cold front.

This change of direction in the wind as you go up in height is called wind shear (southeast at the surface to southwest aloft).

Severe thunderstorms in this area will potentially rotate due to this wind shear and thus there is a pretty good chance for tornadoes today in Oklahoma, Arkansas, Kansas and Oklahoma.

As of 8 am there is already a huge line of showers and storms from Kansas City, MO to Oklahoma City, OK -- as well as a Tornado Watch for most of central OK.

There has already been one intense rain report filed this morning from Butler County, Kansas. The observer 7.5 SW of Leon saw 0.88 inches of rain in one hour with more moving in according to the report. Remember you can look at intense rain or hail reports too by clicking on View Data at the top of the CoCoRaHS page. Then scroll down and click on the report of your choice.

COCORAHS OBSERVER ALERT: Our observers in Missouri, Kansas and esp. Oklahoma need to be alert to changing weather conditions today and if you can safely do so, be prepared to file intense rain and hail reports via CoCoRaHS. Deploy all hailpads in these areas and make sure the rain gauge is ready to measure! Tomorrow this threat may shift to our observers in Illinois and Indiana.

As exciting as the weather can be, and as much as we want any and all repots, please only do so if you can safely.

Tuesday, October 16, 2007

Moderate Risk For Severe Weather

A new storm system will cross the Rockies over the next 36 hours and move into the southern plains by Wednesday.

It is anticipated that it will generate a pretty big outbreak of severe weather across eastern Kansas and Oklahoma, extending into southern Missouri and portions of Arkansas.

The severe weather threat will then shift into the Ohio River Valley by Thursday.

If you live in these areas, you may want to keep an eye on the Storms Prediction Center Web site by clicking here.

Look under convective outlook (listed as Conv. Outlook) in the menu across the top of the page to see the highest threat areas.

Here is another nice resource on the internet to see the current weather observations on a regional basis. Click here.

One that window opens, there should be a map of the US with all kinds of dots representing the most recently reoprted weather conditions at that location.

Green dots mean clear skies, where the blue and red dots are clustered -- well that is where the clouds are.

You will see a few locations are highlighted, such as Little Rock (LIT) and Wichita (ITC). Click one of those and it will bring up a regional map of current weather.

These maps are helpful because you can see the overall flow of wind through the wind vectors. Check out the southern plains states today -- a huge flow of southerly and southwesterly winds overall (at least when I checked while writing this blog Tuesday morning).

Those winds are transporting low and mid-level moisture up into the severe weather target zone on Wednesday.

Monday, October 15, 2007

First Snow Of The Season

Do you know the average date of first snowfall for your community? Here in Denver, we typically see our first snowfall by October 19.

If you don't know, check online (usually your National Weather Service office) has this information on the climate page for major reporting stations in your area.

Take some time to find out and then hold a little fun contest with your friends, family or co-workers to see who can guess the when the first snow of the season will fall.

Friday, October 12, 2007

Hail In West Texas

There were about a dozen reports of hail in west Texas on Thursday. Some of it was quite large, esp. near the town of Maple along the New Mexico state line.

I love reading the daily comment reports on CoCoRaHS -- I see another Maryland observer seeing the first rainfall in 26 days.

There is also a Tennessee observer reporting their catfish are beaching themselves and dying due to the drought. That is so sad, but also a great piece of information to document the extent of this drought in the southeast.

And probably my most favorite from Friday include this report from the observer IL-DP-32 near Lisle, Illinois.

"Still dry my last record of rain was on Aug.25,07 That's 48 days of no rain. Noway near what folks in the southeast are living with but our dryness is putting stress on many plant species. Don't think I would have noticed if I wasn't reading percepitation for CoCoRaHS."

It is great to see so many of you using the CoCoRaHS website interactively. I hope you enjoy the blog! See you Monday.

Thursday, October 11, 2007

It's Cooling Down

A taste of fall has swept much of the nation. Some observers in northern Indiana and Illinois reported a few flakes of snow this morning. Quite the change from the record breaking, summer-like heat of this past weekend!

While observers in Florida are reporting lower humidity for the first time in quite a while.

Folks in Maryland are saying they can't recall the last time there were 2 days of precipitation.

And some observers in southeast Colorado reported near zero visibility due to fog on Thursday morning.

Isn't this a fun time of the year! The weather change is absolutely awesome.

Check out the daily comment reports for more.

Wednesday, October 10, 2007

Dry Times

October is usually a dry month for many parts of the country, and Tuesday was no exception.

Out of over 2000 CoCoRahS reports, only about 25% saw any precipitation.

Most of the totals were on the light side, but there was a few drenchers. 4 stations saw between 2 and 3 inches of rain. Those were in Pennsylvania and extreme sotuh Texas.

Two observers in Cameron County, Texas were able to file intense rain reports. One of those reported 0.90 inches of rain in 30 minutes! That was just northeast of Los Fresnos.

Yesterday I talked about a cold front sweeping across the nation. It looks like another one will move into the northwest later this week.

I know here in Denver we are looking at 70s all week, falling into the 50s by Sunday with light rain showers. That means light snow is once again possible for the mountains.

Time will tell how much progress that front makes across the country as we head into next week.

Tuesday, October 9, 2007

Record Highs, October Chill

One of the first major cold fronts of the fall season is sweeping across the nation today.

Here in Denver, highs reached well into the 80s on Saturday. I was out to dinner in the evening when FROPA happened.

FROPA means Frontal Passage in meteorology lingo.

I literally arrived to the restaurant around 8:15 pm or so and was walking toward the open area to meet a friend. We were both on cell phones walking toward each other.

All of a sudden the wind kicked up, the visibility lowered and the temperature dropped like a rock. I said wow, there was the cold front!

I went back to look at my car thermometer and it had went from the upper 70s when I arrived to the upper 50s.

After dinner, it was down to 43 degrees and overnight we bottomed out between 28 and 32 degrees around town.

I love this time of year!

Other cities probably have like stories, though maybe not quite as dramatic. That is one of the beautiful things about Colorado weather. The changes are usually very abrupt.

Back east, other midwest cities saw major cool downs. Places like Minneapolis and Chicago went from record highs in the 80s to near 90 degrees over the weekend to highs only in the 50s and 60s.

Extreme northern Minnesota even saw a little light snow Monday night.

Friday, October 5, 2007

More About Dew

A CoCoRaHS observer left me a comment yesterday asking if dew contributes much to the water table over the long run? And Does it decrease evaporation so that water already IN the soil is not touched?

The answers are both no.

Dew is not precipitation -- meaning it doesn't fall from the clouds. It is a process that happens at the surface. What you are seeing is the process of a gas (water vapor) condensing into a liquid (dew or if it is cold enough -- frost)

Dew forms on surfaces that do not receive heat conducted from the soils of the earth. (roof tops, car tops, grass, plants, etc.)

SO while it does benefit the surfaces it forms on (meaning it is a brief little drink of water for plants and grass) -- the key words are brief and little.

The dew or frost forms during the coldest part of the night (just prior to and at sunrise) and goes away almost as fast as it forms. As soon as the sun gets above the horizon and begins to warm the air temperature a bit, dew and frost will go back into a gas (water vapor).

So it is a fast and short-lived process, and there really isn't enough of it to make a difference in the water table, and because it is just on the surface, it comes and goes so fast that it doesn't really slow down the normal processes of evaporation.

Now having said that, if you are seeing a lot of frost and dew -- you are probably in a climate that is somewhat moist overall -- so evaporation is going to be slower than in a drier climate.

Let me explain...

As a kid growing up in Arkansas, dew or frost seemed to be a part of almost every single day. And it would stay on the ground through a good chunk of the morning -- say until 10 am. But Arkansas is a very moist climate overall.

Here in Colorado, we don't see dew or frost all that often. And when we do, it evaporates within minutes of the sun rising. We are a very arid climate overall.

It all ties back to the climate. The less moisture (or water vapor) in the air, the less the dew or frost potential will be.

You can gauge how much water vapor is in the air by either looking at the humidity or dewpoint value on your local weather report.

If that isn't available, something else you can look at for a gauge is simply the daily high and low for a location.

The greater the difference in your temperatures between day and night -- the drier the air. The closer the daily high and low temperature are, the more moist the air is.

Dry air cools and warms much much faster than moist air.

That is why places here in the west have such a large spread in daily temperature. That is called the diurnal range. Denver often sees a daily temperature spread of 35 to 50 degrees. Yesterday our high was 83 and the low was 39. That is a 44 degree spread. A great example of our very dry climate.

Back east -- let's say Nashville, Tennessee -- their high was 85 and the low was 71. A difference of only 14 degrees. A great example of a humid and wetter climate.

With nothing more than a daily high and low temperature for a city, you can tell a lot about the weather and climate. The closer the high and low, the more moisture there is. There was probably morning dew and filtered sunshine throughout the day due to passing clouds in Nashville yesterday. Maybe even some patchy overnight fog!

In Denver, just looking at that temperature spread -- you can pretty much bet there were clear skies, maybe a few high passing clouds, and plenty of sun! It was darn dry.

Thursday, October 4, 2007

The Temperature & Dewpoint

Thursday morning was a foggy start for many in the midwest, Great Lakes and northeast. There were also several reports of heavy dew in the comments today.

You can be your own forecaster if you will at deciding if you have a good chance of seeing morning fog or heavy dew by checking the latest weather observation for your area before going to bed.

What you will want to do is look at the temperature and the dewpoint temperature. The closer they are, the higher the chance for fog and dew. If they are equal, that means to air is completely saturated and you will likely have total cloud cover.

There are definitely some other factors involved, namely wind.

If wind is present, it keeps the atmosphere stirred up and would inhibit fog formation.

Here is an example: If the dewpoint is 51 degrees at 10 pm, and you are expecting an overnight low of 52 -- as long as drier air doesn't move in overnight (meaning the dewpoint temperature doesn't fall) and the wind is calm, then you will probably wake up to a muggy, damp morning with dew and fog.

If you have that same scenario with a decent breeze, you will wake up to a grey morning with a deck of clouds overhead, but the wind will prevent the fog from forming most likely at the surface.

But say the low drops to 52 and drier air moves in during the night taking the dewpoint to 40 degrees, you will probably wake up to a sunny morning with just some scattered clouds.

The dewpoint temperature will never be higher than the air temperature -- that would be called super-saturation and it doesn't happen.

Wednesday, October 3, 2007

More Florida Rains

Wow, take a look at the maps for Florida today! In Nolan's most recent email, he said that this state would be one of the most interesting in terms of precipitation patterns and by golly, I think he is right!

An area of low pressure off the east coast dumped tremendous amounts of rainfall in the Jacksonville area on Tuesday.

One station 8.4 miles SSE of Jacksonville picked up a whopping 7.83 inches of rain!

Those of us here in west would have to build an arc to survive that kind of rainfall.

Heavy rain also fell in the Tampa vicinity.

Meanwhile, in the midwest, some CoCoRaHS observers were too close for comfort as severe weather kicked off over a dozen tornadoes -- mostly in Missouri, but a few in Iowa and Illinois.

There was damage and injuries unfortunately from the outbreak.

If you have time, go to View Data at the top of the CoCoRaHS page and then daily comment reports. Choose Missouri and read through some of the comments. A few observers give a play by play report of the precipitation and storms, including times.

It almost makes you feel like you were there watching it unfold.

Tuesday, October 2, 2007

Gully Washer In Florida

Check out today's map of precipitation reports from Florida.

Look along the east coast in Brevard County -- the observer 2.6 miles SSE of Palm Bay picked up 5.70 inches of rain -- saying it was the most rain since the hurricanes of 2004.

Even with only 2 reports coming from the county of Brevard, this is a PERFECT example of how awesome the CoCoRaHS network is at showing the footprints left behind from weather, and just how isolated weather can be.

Just a matter of miles up the coast from the 5.70 inch rainfall in the same county, the local observer reported less than an inch of rain.

I am sure you have seen examples of this where you live, and if you haven't -- try and make it a point to check the local maps where you live the next time you have precipitation -- you will be in awe every single time at what Mother Nature can do!

Monday, October 1, 2007

Severe Storms Move Across Plains

I was in southern Missouri on Sunday afternoon, and although I left before the severe storms moved through, I did see the clouds moving in from the southwest and felt the gusty winds at the surface from the southeast.

Some of the remnants from those storms actually moved through central Arkansas around sunrise this morning. It was fun waking up to the sound of moderate rain. It took me back to when I was a kid.

(It is so rare to wake up to moderate rain or thundershowers in Colorado!)

Portions of Missouri and Iowa saw over an inch of rain on Sunday, as did a few stations in Wisconsin, Florida, Texas, Illinois and South Dakota.

I am heading back to Denver this afternoon so will be able to do a little bit better job of posting once I am back home and in my routine.

Thursday, September 27, 2007

Tropics Remain Active

Tropical Depression 13 rapidly grew into Hurricane Lorenzo over the past 36 hours.

The storm is impacting the western Gulf of Mexico south of Texas.

Meanwhile, Tropical Storm Karen will struggle into the central Atlantic over the next few days. If it survives the wind shear it is moving through, some long-range forecast models show it entering an environment favorable to become a hurricane.

The hurricane season goes through November 30.

Favorite Comment from 9/27 -- Comes from Station MT-VL-5 near Nashua, Montana. They say, "I read my rain gauge at 7 am when I leave for work, but I don't get a chance to report until later (like now).

AWESOME! I too read my gauge in the mornings and sometimes can't find time to report until later that day or even the next. Delayed data entry is just fine -- we appreciate data at anytime.

That is the beauty of CoCoRaHS -- you are building a climate record for your station. Accurate data is more important than punctual data.

However, if you do have a decent rain or snow event, try and file your report as soon as possible because it is very exciting to log in and check the maps to see what happened in your area.

Even A Litle Rain Is Valuable

To see just how important every hundredth of rainfall is, let's quantify it in terms of gallons.

1 inch of rain falling uniformly over 1 acre of land is approximately 27,154 gallons of water.

Here is one more calculation -- there are 640 acres in 1 square mile.

So take Denver for example. There are 153.4 square miles in the city. Multiply that by 640 acres per square mile and you will see that Denver has 98,176 acres.

SO if the city were to receive 1 inch of rain over the entire real estate -- we would multiply 98,176 acres * 27,154 gallons per acre to see that 2,665,871,104 gallons of water fell from the sky. That is over 2 BILLON GALLONS!!

Now there are many other factors obviously to consider. For us here in a dry climate, there is evaporation. For any urban area there is runoff. So not all those gallons necessarily make it into the ground water and surface water, but as you can see, precipitation is the lifeblood of our lives!!

So now you see that even a few hundredths falling over an entire city is extremely important. So the next time you check your raingauge and see just a measily 0.01 or 0.04 -- don't be too let down, go back inside and convert that to gallons.

Then look at your local maps and see the coverage of the rain.

When you think of rain (or melted snow) in terms of gallons, you not only see how important you are as a volunteer weather observer helping us to see what is happening out there in between all the official weather observing points, but you also quickly see that every single drop counts -- LITERALLY!

To convert snowfall -- the standard equivalent is 1 inch of rain to 10 inches of snow -- so for 1 inch of new snowfall, you would run the calculation as stated above and then divide it by 10.

However, that snow to water ratio isn't true for everyone. Here in the Rockies in the dead of winter, we can see snow-water ratios approach 30 inches of snow to 1 inch of water -- thanks to that dry Rocky Mountain powder.

I will be traveling until Monday night so blogging will be tough for me to do -- but if I get a chance, I will.

Have a great weekend everyone!

Wednesday, September 26, 2007

Tale of Two Seasons

The western half of the country is really getting a taste of autumn. We awoke to frost here in the Denver area on Wednesday morning.

Meanwhile, the Great Lakes have been seeing strong to severe thunderstorms and feeling a bit more like late summer.

On Tuesday, severe storms moved through the Chicago area -- producing damage and power outages in Elgin.

Todays favorite comment off the CoCoRaHS comment report comes from the state of Illinois -- observer IL-CK-79. It simply says -- "we needed that!" The observer picked up a nice 0.51 inches of rain from the thunderstorms that moved through the Chicago area.

WOW -- talk about wet in the middle states on Tuesday. 77 CoCoRaHS observers from Oklahoma to Wisconsin picked up 1 inch of rain or more.

4 observers saw more than 2 inches of rain. Three in Missouri and 1 in Oklahoma.

We'd all like to have a day with 1 inch or more of rain so we can measure the precipitation that flows into the overflow can. That is always fun!

But even small amounts of rain, like 0.07 inches or 0.14 inches are extremely valuable. Heck, even 0.01 or 0.02 is helpful. Why?

Look for the answer in tomorrow's blog entry.

Tuesday, September 25, 2007

Wacky Fall Weather

If you were in Fort Wayne, Indiana on Monday -- you experienced a record high. In fact, the temperature shot up a full 34 degrees in just 6 hours.

The city climbed from a morning low of 56 degrees at 7:46 am to 90 degrees by 1:25 pm.

The top temperature was 92 degrees set at 3:34 pm.

South Bend also set a new record high of 91 degrees. The previous record readings in both cities were in the upper 80s and had stood since 1941.

Indianapolis also set a new record high on Monday of 92 degrees. It was only the 4th time on record that a temperature hit 92 degrees or higher this late in the season. Temperature records date back to 1871.

In Nebraska on Monday there were a few tornado touchdowns in the south-central part of the state. Hail fell and damaging winds blew from Nebraksa to Minnesota.

Today the severe weather threat will shift into the Great Lakes states.

Meanwhile here in Colorado, as I sit and write this blog from SE Denver, it is 43 degrees with drizzle at 1:09 am.

Ahhh, it must be fall!

Be sure to look at some maps and the comment reports before leaving the CoCoRaHS site today. There should be some interesting observations.

To see comments, click on View Data in the top menu and then Daily Comment Reports. To see all states, choose "select state" in the menu and then click "search".

Here in Colorado, we should see several reports of snow or a mix at least from the mountain observers.

Monday, September 24, 2007

Varied Precipitation Reports

Some residents along the Front Range of Colorado awoke to small hail and heavy rain Monday morning. Where I live in the SE Denver metro area, it was overcast with peaks of sunshine while others were getting rain.

That is the beauty of CoCoRaHS.

In the Denver metro area, there are only 4 official automated points of weather data. But CoCoRaHS allows us to see precipitation details in between those 4 stations. A morning thundershower or thunderstorm is quite special in a dry climate like Colorado because usually we need daytime heating to cause enough instability for a storm.

I can recall growing up in Arkansas running to the bus stop on many mornings, dodging the lightning and rain and sometimes hail.

For those not in Colorado, we are known for our rapidly changing weather conditions, especially in the mountains.

This morning, rain rapidly changed to snow along with driving winds between Idaho Springs, Aspen and Vail -- closing portions of Interstate 70 over the Continental Divide and causing some accidents outside of the Eisenhower Tunnel.

For both residents and visitors, it is time to dig out the winter survival kits to keep in the trunk of your car because you just never know what you may run into over the higher passes. Other colder climates will need to do this in the coming weeks too. (like Wisconsin, Wyoming, South Dakota and Montana for example)

The wettest location in the CoCoRaHS network on Sunday was Bennett County, South Dakota. Two different stations each had nearly 2.00 inches of rain. Check it out on the maps by clicking here. Then select South Dakota in the state pull-down menu and Bennett County in the Cities/Counties list.

Observer WY-NT-22 says it is feeling like fall in his or her Monday comment.
AMEN to that!!

Sunday, September 23, 2007

Fall 2007 Arrives

Regardless of how the weather outside feels today where you live, it is now fall.

For some the signs are already here, especially in the Rockies where the annual fall color show has begun.

One CoCoRaHS observer in Cook County, Illinois has noticed some golden leaves on the Locust trees.

As the sun angle in the sky gradually lowers in the days ahead, and the days become shorter, cold air will build across the Arctic and occasionally move south in the form of strong cold fronts.

These fronts will bring anything from snow and cold to severe weather across the lower 48 states.

The average first date for measurable snowfall in Denver is October 19. But for many cities in colder climates of the US, that date doesn't come until mid-November, including Chicago and Indianapolis.

A measurable snowfall is defined as being 0.1 inches or more.

Now is a great time to get out the snowboard and snowstick for those in the snowy climates, and to brush up on your snow measurement skills.

Any questions? Feel free to ask. In the days ahead we'll do some reviewing in the blog, as well as in Nolan's email updates.

The other day I suggested if you have time -- you should read some of the daily comment reports from CoCoRaHS observers in your state and around the nation.

To do this, go up to the menu across the top of the page and click on "View Data" -- then click on "Daily Comment Reports" when the page loads.

To see all states, change your pull-down menu to say "Select State" -- otherwise select the specific state you are interested in.

Here is a great comment from an observer near Chadwick, Illinois on Sunday morning.

"Have no idea where the .02 moisture came from - maybe the big fat bublebee dead in the top funnel. Temp 53, sunny, clear and no wind."

Here is a data entry tip for those who are busy with work and other projects. A zero entry for precipitation may not seem like a big deal, but to a climatologist, it is just as important as that 6.01 inch rainfall.

You never know how a zero report could come in handy. One example would be if an observer did get that huge 6.01 inch rain. Seeing who got rain and who got zero precipitation is extremely helpful for a climatologist or meteorologist reconstructing the storm.

If you are extremely busy like myself (working 2 jobs plus keeping up with life in general and hobbies like CoCoRaHS) you may find it helpful to keep a written log of precipitation during the week, then sit down on Saturday or Sunday and do the "catch-up" data entry.

In a month like September when there are ALOT of zero reports, it is ok to do this.

Just try your best not to FORGET to do that "catch-up" data entry.

In the event you do get a nice dose of rain or snow, it is awesome to file that report as fast as possible because now that CoCoRaHS is so big, there are literally thousnads of people logging in to check those maps each morning to see who got big rain and who did not -- users include fellow volunteers, the media, and the National Weather Service.

Saturday, September 22, 2007

Last Day Of Summer Is Tale Of Two Seasons

Depending on where you are located this weekend, the last day of summer is bringing everything from snow to tornadoes.

A large area of low pressure spinning near southern California will keep the west cool and damp this weekend.

What is a cut-off area of low pressure? It is a low pressure that is not in the main flow of jet stream winds in the upper atmosphere. Cut-off low pressure areas will sit and spin until they either dissipate or eventually drift close enough to the jet stream flow that they get picked up and moved off.

Sometimes a cut-off low pressure can be bad, such as earlier in the summer when a cut-off low pressure kept Texas and Oklahoma very wet for several weeks.

In this case it is GREAT news for the Los Angeles area, which saw the first rainfall in 6 months and the heaveist September rain in 2 decades!

The rain caused some flash flooding across the large burn scars from summer fires in the vicinity.

Meanwhile the eastern states will end summer on a very warm note, so get out and enjoy because it is the time of year when things could change quickly.

And tropical depression #10 moved onshore near Ft. Walton Beach, Florida Friday. It wasn't the wind and rain maker many feared, but there were several tornadoes reported with the storm system.

One twister caused significant damage outside of Orlando.

And did you by chance see a radar of the upper midwest on Friday? A long line of severe thunderstorms (also known as a squall line) stretched from Iowa to the upper peninsula of Michigan at one point. The storms brought rain, wind and hail to the area. Much of Wisconsin was under a tornado watch at one point on Friday.

Friday, September 21, 2007

September Weather

20 CoCoRaHS stations have checked in with an inch or more of rain as of 10 am Mountain Time on Friday morning. The reports came from Wisconsin, New Mexcio, North Carolina and South Dakota.

One of those reports came from observer NM-ED-3, who lives on the northwest side of Carlsbad, New Mexico.

A thnuderstorm moved over that region just after 10 pm on Thursday night, and dropped 1.10 inches of rain in 15 minutes. The observer described the flooding as severe with over a foot of water rushing down the streets.

That much rain in 15 minutes is a lot for any location, but especially in a dry and arid climate like New Mexico.

Although our network isn't up and running yet across Florida, there have been some drenching rains there this week too. The city of Jacksonville has recorded over 10 inches!

Those soaking rains will spread west along the central Gulf Coast with the current tropical disturbance in that part of the world.

If you are heading to New Orleans this weekend, bring the rain gear!

Thursday, September 20, 2007

Eyes On The Tropics

Forecasters will be watching the tropics over the next few days as an area of disturbed weather off the west coast of Florida could develop into either a tropical or sub-tropical storm.

You can follow the latest on the National Hurricane Center's website by clicking here.

Although we'd hate to see a tropical system threaten our friends along the Gulf Coast, the rain that could spread into the southeast would be awesome -- since they have been in a widespread drought this summer. Stay tuned to see how this plays out!

If you are traveling to the western coast of Mexico or the Baja of California over the next few days -- prepare to deal with Hurricane Ivo. It may weaken into a tropical storm before landfall, but will still bring plenty of wind and rain to the region.

Favorite observer comment from Wednesday: Finally a smidge to report! This comes from 6.8 miles south of Arlee, Montana.

Wednesday, September 19, 2007

Hail Falls From Kansas To Wisconsin

The CoCoRaHS maps today will be interesting to look at -- especially in states like Iowa, Kansas, Wisconsin and Nebraska.

Strong to severe thunderstorms rolled across the plains on Tuesday.

There was one intense rain report filed 2.6 miles north of Independence, Missouri on Tuesday. The CoCoRaHS observer there saw 0.40 inches of rain in 30 minutes.

Hail fell across southeast Nebraska, eastern Iowa and southwest Wisconsin. The thunderstorms also produced strong winds that caused damage.

Sustained winds at 46 mph with gusts to 79 mph were reported 1 mile north of Vinton, Iowa. Not too far away in Keystone (Benton County) a 55,000 bushel grain bin was blown over.

Click here for a complete listing of storm reports sent to the National Weather Service.

Do you ever take time to read through the daily comment reports here on CoCoRaHS? There are literally hundreds -- but it could be fun to read for your state.

One of my favorites from Tuesday came from the observer 3.0 miles ENE of Perrin, Texas (Station TX-JC-2).

He is a 185 pound man that was knocked to the ground by a wind gust from the outflow boundary of a nearby thunderstorm around 8 pm Monday evening. Now that is some powerful wind!

Meteorologists keep close tabs on outflow boundaries because they can do a few different things. Sometimes they create new thunderstorms, essentially acting like a small-scale cold front. They can also linger and be the focal point for new thunderstorm growth with daytime heating on the following day.

Tuesday, September 18, 2007

The Transition Between Seasons

Summer 2007 is rapidly drawing to a close -- and Mother Nature is busy showing us hints of the days ahead.

Many have experienced a pre-autumn chill over the past few days. Snow was even reported in northern Minnesota over the weekend as lows dipped into the 20s and 30s.

Here in Colorado, snow fell in the mountains above 11,000 feet Sunday night, closing Trail Ridge Road in Rocky Mountain National Park for a few hours Monday morning.

And from northern Colorado to Wyoming and Montana, the annual fall color show is underway.

Another sign of the transition from summer to fall is severe weather -- yes I said severe weather! Not so much for us in the Rockies, but CoCoRaHS states like Iowa, Missouri, Indiana, Illinois and points south can see short but potent outbreaks of severe weather this time of year. Some southern states actually see a second peak in severe weather during the autumn months as cold air from Canada collides with warm moist air hovering along the Gulf of Mexico.

Something that we will see less and less of in the days to come are Intense Precipitation Reports for heavy rain on CoCoRaHS as the cold weather season takes over. But if you happen to experience intense precipitation in the days ahead and can file a report, we'd love to document this information.

One observer in La Plata County, Colorado experienced 0.42 inches of rain in 6 minutes on Monday afternoon. And in Santa Fe County, New Mexico -- a CoCoRaHS observer saw almost 2.50 inches of rain in 4 hours from a series of slow-moving thunderstorms.

You can check out both of these reports filed on 9/17/2007 by Clicking Here. It will default to Colorado, but if you choose "Select State" in the pull-down menu it will pull any reports from all CoCoRaHS observers.

Tuesday, September 4, 2007

Welcome To The CoCoRaHS Blog!

Hello -- I am Chris Spears, a CoCoRaHS volunteer since 2002. I worked with Nolan Doesken as a CoCoRaHS student intern while finishing my meteorology degree at Metropolitan State College of Denver.

I am very passionate about both people and the weather. So I approached Nolan and Henry at CoCoRaHS headquarters about hosting a weather blog on the CoCoRaHS website.

This will not be an opinionated blog and will not cover topics of conflict, such as climate change. The purpose is to talk about the current weather and the data you all collect and archive every single day.

I am truly a climatologist at heart, so I will also attempt to throw in as many neat and interesting weather facts as possible.

I hope you enjoy the blog --