Monday, September 10, 2018

Tropic Thunder

The tropical Atlantic was fairly quiet this summer. Until last week there were only five named storms, only two of which reached hurricane strength.

Map showing first five tropical systems in the Atlantic in 2018
Tropical Storm Gordon made landfall in the Gulf last week and its remnants brought heavy rain to the Midwest and mid-Atlantic this past weekend.

Since last week, however, three new storms are churning way in the Atlantic, and one area of disturbed weather over the northwestern Caribbean Sea has a 60 percent chance of developing into a tropical system within the next five days.

The focus of all the attention the last few days has been Hurricane Florence. Florence started as an area of low pressure that moved off the African Coast 12 days ago on August 30. The depression became Tropical Storm Florence on September 1. Florence attained hurricane strength for the first time on September 4. The storm encountered an area of upper level shear as it moved west, which weakened Florence considerably and it was downgraded to a Tropical Storm late on September 7. All indications were that Florence would reach hurricane strength again, and yesterday morning it did. The storm underwent rapid intensification today, and as of this writing Hurricane Florence is a category 4 storm (maximum winds 140 mph) heading for the Southeast Coast of the United States. It's possible it could briefly reach Category 5 strength on September 11.

We are also keeping an eye on Hurricane Issac. As of this writing it is a Category 1 storm with top winds of 75 mph. Its projected path will take through the Lesser Antilles and to the south of the Dominican Republic by Saturday as a tropical storm. Its future beyond Saturday is uncertain, but it will be over the warmer waters of the Caribbean Sea.

Hurricane Helene is currently the last in line of the storms in the Atlantic right. This storm is expected to re-curve to the north and weaken by Thursday.

Meanwhile, in the Pacific Tropical Storm Olivia is heading for the Hawaiian Islands. A Flash Flood Watch has been issued for all the Hawaiian Islands though Thursday night. Olivia is forecast to produce total rainfall amounts of 10 to 15 inches. Isolated maximum amounts of 20 inches may occur along the windward sections of Maui County and the Big Island.

Forecast track for Tropical Storm Olivia

Back to Florence, though. The various forecast model projections were the subject of much discussion the past few days. There initially was a wide spread in possible tracks, including the possibility that Florence could re-curve north before reaching the coast. However, as the weekend progressed the models increasingly began to converge on a solution showing landfall somewhere along the Southeast Coast of the U.S. The current forecast (5:00 p.m. EDT 9/10) brings Florence ashore somewhere between Charleston, SC and Cape Hatteras, NC sometime on Thursday likely as a Category 4 storm.

The footprint of Florence is going to be very large, probably as big as South Carolina, North Carolina, and Virginia combined. While winds will certainly be a big concern especially close to landfall, the rain footprint of Florence is what is really scary. Indications are that Florence will stall over the Carolinas blocked by a strong ridge of high pressure over the northeast U.S. The storm's circulation will continue to draw moisture from the Atlantic into the Carolinas, Virginia, and northward. This will mean days of heavy, flooding rain. Here is the latest precipitation forecast for Florence from the Weather Prediction Center.

While the winds with Florence will be significant if the forecast holds, it is the  storm surge and the rain and resultant inland flooding that will make this a notable storm.

CoCoRaHS observers: If you are in the Carolinas and Virginia please remove the funnel and inner cylinder from your gauge as they can become projectiles in high winds. In heavy rain the outer cylinder alone will also be more efficient for catching heavy rain (no splashout from funnel). If you're given evacuation orders, please follow them. Your safety is our number one concern!

For the latest information on Hurricane Florence visit the National Hurricane Center website.

Thursday, May 31, 2018

Evapotranspiration and Water Balance Maps Now Available

Atmometer (E-T Gauge)
About six years ago CoCoRaHS added measurement of reference evapotranspiration (ET0) to the phenomena observers can measure. Evapotranspiration is the sum of evaporation from ground surfaces and the transpiration of water to the atmosphere from plant leaves, and is a function of temperature, wind speed, relative humidity, and solar radiation. On average more than half the precipitation that falls is returned to the atmosphere through ET. There are about 120 observers across the the U.S. and in Canada currently measuring E-T using a special E-T gauge called an atmometer. You can read more background on CoCoRaHs E-T measurements in this blog post from 2013.

Recently the Midwestern Regional Climate Center (MRCC) in partnership with the National Integrated Drought Information System (NIDIS) developed are series of maps of E-T and water balance measurements using CoCoRaHS data. These maps can be found on the Midwest Drought Information page in the Midwest Climate Watch section of the MRCC web site.

There are maps of 7-, 14-, 30-, and 60-day accumulations of E-T for the Midwest region and for the continental U.S. and southern Canada. A second set of maps displays water balance calculations for the same periods as E-T. Water balance is the total precipitation minus the total E-T for a designated period. Water balance charts  are available on the CoCoRaHS web site and show the change in water balance over time at a location along with daily E-T and precipitation values. All the maps are updated each day.

Here is today's map of 7-day E-T for the U.S. and Canada. Note that only stations with 100 percent data completion in that period are displayed. E-T occurs every day, so stations with missing observations cannot be used to compare with other stations.

This is a 14-day water balance map. It's pretty clear where it's very dry and has been very wet.

An advantage to having this data plotted spatially is we can see where more E-T observations are needed. ET does not vary to the same extent as precipitation (it's more similar to temperature), so multiple measurements in the same general area are usually not needed, unlike precipitation. ET measurements are only made during the warm season, since freezing temperatures can damage the gauge. There a few stations in the south and west that measure E-T year 'round.

If you are interested in measuring E-T at your location contact CoCoRaHS headquarters for more information.

Friday, April 20, 2018

CoCoRaHS 36"+, 24-hour Rainfall in Hawaii Confirmed

Lost in the coverage of heavy snow in the Midwest and wildfires in Oklahoma this past week was an incredible rain event that occurred in Hawaii over the weekend. The rain fell beginning late on April 13 and continued through Sunday, April 15. In produced severe flooding over portions of Hawaii, particularly over east Oahu on Friday night and across Kauai from late Saturday through Sunday.

The entire island was under a flash flood warning on Saturday and Sunday.Here are the 24-hour rainfall amounts from Kauai on Sunday morning, April 15.

Throughout the storm on the night of April 14 until the morning hour of April 15, the CoCoRaHS observer at HI-KI-24 made several trips out to the rain gauge to measure than rain before it over-topped the gauge. Nolan Doesken from CoCoRaHS headquarters contacted the observer to get more details on this incredible event. Here is a timeline of what the observer measured and reported.

HI-KI-24 Hanalei 3.0 W (Wainiha)
Saturday, April 14, 2018

Time HST Precip, in. Duration (hrs)
7:30 a.m. 2.96 24
2:20 p.m 5.00 6.8
5:30 p.m 7.55 3.2
7:00 p.m. 7.33 1.5

Local damage began to occur. After this observation the observer evacuated the house and stayed in their car which was parked up the hillside from the house along the road.

Sunday, April 15, 2018

Time HST Precip, in. Duration (hrs)
1:30 a.m. Gauge was nearly full. Observer did not measure precisely at this time, but conservatively estimated 10.00 inches of rain since 7:00 p.m.

6.45 a.m. 6.55 5.25

Monday, April 16, 2018

Time HST Precip, in. Duration (hrs)
6:30 a.m. 2.14 23.75

The total Sunday morning from the incremental measurements was 36.43 inches. The final total of 36.49 inches includes an estimate of what might have been lost during to spillage during the incremental measurements (the observer does not have an extra outer cylinder). He made the measurements with the help of a friend, wading out to the rain gauge for the measurements and making them in the rain. Nolan indicates the observation is fully valid and if anything may be a bit of an under-report.

The observer commented that based on the location of thunder and lightning, the heaviest part of the storm seemed to be a few miles east of his location. This observation seems to be borne out by the radar estimated precipitation. The maximum amount on the Storm Total Precipitation image below is 27.5 inches.We know that the total rainfall was considerably higher. The location of CoCoRaHS rain gauges are plotted on the radar image.

Radar estimated precipitation for the 50-hour period ending
at 2:13 p.m.HST April 15, 2018.

While the observer's house barely escaped flood damage, there was damage close by. One notable comment from the observer was that somewhere around 7:00 p.m. the roar of the nearby Wainiha River began dominating over the sound of thunder to the east.Two nearby houses were washed away, and a large 18-inch diameter log ended up in a neighbors living room. The road was washed out in three places. Roads and homes were flooded across much of eastern Kauai, and as of April 18 more than 425 people had been evacuated.

 U.S. Coast Guard video of overflight of area near Hanalei Bay, Kauai, April 15, 2018

What caused this heavy rain was the interaction of an upper level low and tropical moisture. On Friday a trough was crossing north of Hawaii, but the bottom of the trough cut off and became a closed low. This closed low then drifted westward across Hawaii, tapping into low level moisture fueling the storms.

Here is a three panel image that shows the 500 millibar analysis beginning at 2:00 a.m. HST on April 14 showing the low drifting west, followed by a chart of the total precipitable water.

Total Precipitable Water at 2:00 a.m. HST April 15. The Hawaiian Islands are circled.

The National Weather Service in Honolulu reported that the rain gauge in the town of Hanalei collected 28.15 inches of rain from early Saturday morning into Sunday morning (April 15) before the gauge stopped working at 2:00 a.m. HST. The 24-hour record for that location is 28.54" set on March 5, 2012. It's highly likely that this record was broken.

In Wainiha, where our CoCoRaHS observer is located, an automated rain gauge recorded 32.35 inches of rain for the 48-hour period ending at 6 PM HST on April 15, 2018. This rain gauge recorded 19.54" for the 24 hour period the previous record for a 24-hour total in Wainiha was 16.70 inches on January 6, 1969. The confirmed CoCoRaHS total more than doubles that record. The total rainfall for HI-KI-24 for the 72-hour period ending at 6:30 a.m. HST on April 16 was a whopping 41.59 inches.

The 24-hour record rainfall for Hawaii is 38.00 inches at Kilauea Sugar Co. Plantation (Kauai) on January 24-25, 1956. It is an estimate, but is listed as the record because it was obtained from a reliable rain gauge and is deemed conservative by an inch or more.

Monday, April 9, 2018

Tornado Detection by Radar Started 65 Years Ago Today

The first hook echo identified and photographed on radar.
Sixty-five years ago, out in the middle of central Illinois cornfields at the University of Illinois airport, electrical and radar engineer Don Staggs deferred shutting down a radar being used for rainfall research because he noticed something peculiar about the radar return he was seeing. That decision turned out to reveal the first detection of a tornado "hook echo" by radar. We have come a long way since then. The dual polarization Doppler radar now being used by the National Weather Service can detect rotation in storm before tornadoes develop, adding critical lead time for tornado warnings.

My blog post on April 9, 2013 relates the story behind the detection of the first hook echo on the 60th anniversary of the event.

Friday, March 30, 2018

A Bullseye of Dry

The past winter season (December-February) was a little on the weird side. The west coast, which normally experiences it's wet season in the winter, was pretty dry. It was cold across the Plains and Midwest, but snowfall was way below average in many areas. Winter had a late surge in the northeast in late February and March. However, one aspect of the last five to six months that has been interesting to watch is the fairly rapid development of severe to exceptional drought in the panhandle region of Texas and Oklahoma and adjacent portions of Colorado, Kansas and New Mexico.

Here is the U.S. Drought Monitor as of today, showing parts of this area in Extreme Drought, compared to the Drought Monitor in early October.

Dryness expanded and intensified through November and December, and by early January the first depictions of Extreme drought were showing up on the U.S. Drought Monitor. 

By early March an area from the Four Corners region to the panhandles was painted with Extreme Drought, with a small area of Exceptional Drought in northern Oklahoma. That small area has doubled in size in the past two weeks.

The precipitation map for the past 6 months depicts the seriousness of the precipitation deficit.

This map from the Oklahoma Mesonet demonstrates the incredible precipitation gradient across Oklahoma the past four months, ranging from only an inch in the panhandle to more than 25 inches in the southeastern part of the state.

Then there was this note included in the Area Forecast Discussion by the NWS Amarillo office on March 28.

We have some dedicated CoCoRaHS observers that have been submitting daily observations, mostly zeros, throughout the development of this drought. Here is a list of CoCoRaHS rainfall totals under one inch from Texas, Oklahoma, Colorado, New Mexico and Kansas October 1 through March 28 for all stations which had observations for at least 90 percent (161) of the days in this period.
Station Number Station Name Total Precip Total Snow
 CO-BA-27  Stonington 8.6 SE 0.28 1.3
 CO-LA-16  Kim 8.8 SSE 0.58 2.7
 KS-HM-3  Syracuse 14 SSE 0.59 0.0
 TX-LK-24  Ransom Canyon 0.4 ENE 0.64 0.2
 NM-SC-26  Lemitar 0.7 NNE 0.67 0.0
 KS-SV-18  Hugoton 0.6 NNW 0.69 0.0
 NM-SN-39  Rio Rancho 3.3 ENE 0.73 0.0
 NM-SN-62  Rio Rancho 3.0 WSW 0.75 0.0
 KS-WH-9  Leoti 6.8 NNW 0.78 7.4
 TX-LK-14  Lubbock 5.3 SSW 0.79 0.4
 NM-SN-43  Rio Rancho 3.5 W 0.80 0.3
 CO-OT-25 La Junta 1.0 S 0.82 1.8
 NM-SJ-19  Farmington 3.4 WSW 0.83 0.0
 NM-BR-205  Albuquerque 8.9 NW 0.83 0.0
 NM-BR-36  Albuquerque 5.9 WNW 0.86 0.0
 TX-LK-59  Wolfforth 4.6 S 0.86 0.5
 TX-LK-7  Lubbock 6.7 SW 0.87 0.3
 NM-BR-7  Albuquerque 7.1 SW 0.88 0.0
 TX-LK-77  Lubbock 6.4 NW 0.89 0.0
 CO-BN-8 Las Animas 8.1 NE 0.92 3.4
 NM-BR-152  Albuquerque 2.9 W 0.92 0.0
 CO-OT-28 La Junta 1.6 SW 0.93 1.5
 NM-SJ-32  Kirtland 21.7 S 0.95 0.2
 NM-TR-1  Mountainair 1.0 S 0.96 1.0
 TX-LK-81  Lubbock 3.0 S 0.96 0.0
 NM-BR-215  Albuquerque 5.3 W 0.96 0.0
 KS-HM-19  Syracuse 3.1 NNE 0.96 0.0
 KS-FO-23  Dodge City 12.7 S 0.98 1.2

The winds aloft, particularly in December and January, were west-northwest on average in this part of the country. Any moisture heading toward the Texas and Oklahoma panhandle region would get wrung out of the atmosphere as the air was forced up on the west side of the Rockies. Any low pressure systems that developed tended to be steered east before they started to develop. What the drought-affected area needed, and didn't get, were some strong low pressure system developing on the lee side of the Rockies that could tap into moisture from the Gulf of Mexico to produce precipitation.
These maps depict the average 500 millibar height pattern (~20,00 ft) for the months of December, January and February. Winds at this level blow parallel to the contour lines. The arrows show the general direction of the wind at this level.

Although this region did get a little rain this week, the operative word is "little". The latest forecasts keep the drought area dry for at least the next week or so.

Tuesday, March 20, 2018

Are You Up for a Spring Challenge?

Those of you in the Northeast might be saying "We've been challenged enough!" with the recent train of nor'easters passing thought, but this challenge will be less stressful.

NASA's GLOBE (Global Learning and Observations to Benefit the Environment) is running a spring challenge for cloud observations and is encouraging citizen scientists (that's you, CoCoRaHS observers) to participate.

From now until April 15th you can take part in the challenge by downloading the free GLOBE Observer app for iOS or Android. You can also submit you observations online through the web site. However, once you have the app, you can snap and send cloud observation photos directly to NASA using the app.

Participants are invited to enter up to 10 cloud observations per day from now to April 15. GLOBE and GLOBE Observer participants with the most observations will be congratulated by NASA scientists with a video posted on the NASA GLOBE Clouds website.

I spent some time on the GLOBE Cloud web site recently to find out more about what this entailed. There is plenty of training material available on cloud types and cloud observations, including a nice downloadable cloud chart as well as an online cloud chart, and a guide to Observing Cloud Types.

The optimal observation is one that coincides with a satellite pass over your location, and there is a tool on the web site where you can get these. There are at least five orbiting satellites that collect cloud data. you will need your latitude and longitude for this. The app will determine this if you have location services turned on on your phone or tablet. That's also available from your CoCoRaHS account if you don't have it written down somewhere. The app allows you to set an alarm to alert you to upcoming satellite passes.

Clouds are important to Earth's energy balance. They reflect, absorb, and scatter sunlight as well as infrared emissions from earth. The type of cloud, its height, and transparency all are factors that have to be addressed. Satellites can detect clouds, and while they are great tools, they have limitations especially when it comes to the details. For example, satellites see the tops of clouds, but not the bottoms. Satellites may also have a hard time differentiating high, wispy thin cirrus clouds (composed of ice crystals), from deep snow cover on the ground. So while satellites look down on the clouds, GLOBE cloud observers are looking up.

Altocumulus clouds.
Photo: Steve Hilberg

The app (available on iOS and Google Play) walks you through the steps of making an observation. The following information is required for each observation:

Date, time, location
SKY:clear, cloudy, obscured
COVERAGE: what percent is covered
TYPE:  cloud/contrail types
Visual opacity
Surface conditions

One observation is allowed per time stamp, and it's recommended that you wait 10 to 15 minutes between observations so changes in the sky can be recognized.

Also, there is this important reminder:

"Reminder: This protocol includes a category of “No Clouds” which should be reported whenever there are no clouds visible in the sky. A “No Clouds” report is just as important as a “Clouds Observable” report in helping understand our Earth’s system. If “Clouds Observable” is reported, follow the observation hints located in the left navigation column."

Sound familiar, CoCoRaHS observers?? Blue sky (zero) is an observation.

You can also manually observe clouds and then enter the data into the GLOBE observer web site. A printable data entry form is provided for this.

I did try the app out and encountered a couple of hiccups. The data entry part, up to the photos, was quick and easy. However, there seems to be a little bugginess in the photo function. After messing with this a number of times I think I figured out how the app works with respect to taking photos (I could find no directions anywhere on how this works). So, you may want to hold on to these directions if you are going to use the app. I tested this on my Android phone.

 After your last entry of surface observations, you will see the photo screen.

If you want to take a photo using the app, select Take Pictures. A second screen will appear showing your camera view, along with N S E W Up Down on the bottom left, and a circle in the middle of the screen. 

IF the correct direction is showing for the direction you are pointing at (the "W" in this case), move the camera until the direction letter is lined up with the center circle. Once it is it will turn green and a photo will automatically be taken. Click DONE in the lower right of the screen and you will exit to the next screen, which will show your photo(s) at the bottom. this function, if it's working, is actually nice because by lining up the W with the circle it forces you to tilt the camera up at the correct angle

If you want to delete the photo, tap the photo thumbnail and select Delete. If everything looks OK, then click FINISH at the very bottom of the screen (you have to scroll down). The next screen will give you the option of reviewing and submitting your observation.

You can also add photos manually (second option). Selecting will take you to the Take Pictures screen. Tap the direction you are taking your photo. You have the option of taking a photo with your camera or choosing an existing photo from your photo gallery. If you are having issues with the first option the manual option is easier. 

The compass direction showing on my screen was off by 90 degrees for some reason (I was shooting north but it indicated west). There was some message about the phone's compass but it disappeared from the screen when I initially tried this and I couldn't seem to resurrect it. When I checked my phone with an independent compass app it was spot on. I don't know if the direction is determined by the internal compass or the GPS.

Also, once I took the photo in landscape mode the GLOBE screen would not return to portrait mode, and the camera was on in the background behind the menu. Even if I closed the app and reopened it it was still in landscape mode. Unfortunately there is no real app-specific help within the app itself to deal with these functions. Before you use the app to make an actual observations I would go through a few dry runs just to see how it behaves on your phone. None of the data is actually sent until you tell the app to send it. However, editing your observation is clunky. Editing takes you to the start of the data entry and you have to go through each screen again.

Once your observation is in the system, ground observations of clouds are matched with satellite observations. If your observation coincides with a satellite observation, you will received an automatic "match" email, which summarizes both your ground observation and the satellite observation. It takes anywhere from one to seven days to receive the satellite data, depending on the satellite. You can read more about the satellite comparison on this page.

This is a great opportunity to spread your citizen scientist wings in a weather-related way, and the data you collect may be used by NASA scientists for their research on clouds.

While this "spring challenge" only runs until April 15, cloud observations continue year 'round. Despite a few little glitches with the app, this is a worthwhile addition to your observation activities.

Wednesday, January 31, 2018

Winter 2017-2018 Update - It's Not Over Yet

We are two-thirds of the way through climatological winter (December-February), and it has been a rather unusual one so far in many different ways. Winter weather won't necessarily stop in March, or even April (or in one or two recent cases, May), but for statistical purposes December through February is our target period.

Winter weather got off to a late start in most of the country as much warmer than normal weather prevailed in much of the country. The big news in December prior to Christmas was the tinder dry weather in the west and the devastating wildfires in California. There was also some heavy snow across parts of the southeast the second week of December.

The weather pattern changed dramatically the last week of December, and cold Arctic air spilled into much of the eastern half of the country. It persisted through the the middle of the month with one or two brief breaks. This pattern change also brought much needed rain to California. Unfortunately the rain triggered deadly mudslides as it washed away hillsides left bare by the earlier wildfires.

It was during this period the snow cover across the U.S. was at the highest of the season so far with 53.6 percent of the lower 48 states with snow on the ground. This was also the time when all 50 states had measurable snow on the ground. There was a notable lack of snow in the Cascades and Sierra Nevada.

The Accumulated Winter Season Severity Index (AWSSI) in mid-January depicted a severe to extreme winter in much of the eastern U.S. as well as in the northern Rockies. Below normal snowfall in the Midwest and Plains contributed to the average to moderate categories there, despite cold weather.

So, here is how we stand at the end of January. Temperatures have been normal to below normal across most of the country east of the Rockies., while it remains warm in the western U.S.

Season-to-date snowfall is an odd picture, with much above normal snowfall in the Gulf Coast states the southeast, and in the northern Rockies. Snowfall is near to above normal around the Great Lakes and New England. Snowfall is well below normal in the northern Plains, central and southern Rockies, and much of the Midwest.

As of today snow cover was down to about 25 percent across the U.S., half of what it was two weeks ago.

The precipitation map demonstrates the disparity in winter precipitation across the country to date. It has been dry in much of the west, and very dry from eastern New Mexico through the Texas and Oklahoma panhandles.

The dry weather in California, in what is normally the wet season, is having a significant impact on snow in the Sierra Nevada, crucial for water supplies the rest of the year. Snow water equivalent (SWE) is approaching record lows for a number of locations for this time of the season. SWE is also very low further east in the central and southern Rockies.

The last two weeks of mild weather is also reflected in changes in the AWSSI with a drop of one category in the Midwest and in the east.

Winter weather looks like it will make a return during the first two weeks of February, at least, so there will be more to factor in before this winter is over. A broad scale trough is forecast to reestablish over much of  the U.S. in the next week, funneling more Arctic air into the country.

500 millibar forecast map for 6:00 p.m. Thursday, February 8, 2018.

Monday, January 15, 2018

Singing Ice

Many people don't find a lot to like about winter weather. I'm good with everything about winter except the occasional howling winds, and freezing rain. Even if you aren't a fan of winter weather, there are a lot of interesting phenomena to observe during cold weather. Many of you have probably seen the "throw boiling water into the air when it's -20°F" video as one example. Here is a video I came across the other day which describes the physics behind the phenomenon of "singing ice".  This video was produced by National Public Radio science and hosted on their Skunk Bear YouTube channel. It's a worth a watch!

Thursday, October 26, 2017

You Won't Regret Spending 8 Minutes of Your Time on This

Lightning. Dust storms. Hail shafts.  Explosively developing thunderstorms. Microbursts. Shelf clouds. Rainbows. Spectacular Southwest scenery.

If any of these things interest you, then you will want to be sure to view photographer Mike Olbinski's latest film, "Monsoon IV".

Olbinki is a professional photographer from Phoenix, AZ. His main business is as a wedding and family photographer, but he also spends a good amount of time chasing weather, the Southwest Monsoon in particular, and storms in general. I wrote a blog post about Olbinski's first monsoon video in 2014.

He wrote a short blog post about his activities this past summer, and you can view the video there as well. His Storm Blog contains amazing photos accompanied by description of his chasing activities associated with that particular photo.

This is best viewed full screen on your computer, but for the full experience view it on a large screen HDTV if you can.

Monday, September 18, 2017

Notes on Hurricane Irma

Hurricane Irma on September 8.
Five days ago the last remnants of what was once Hurricane Irma fizzled over the eastern U.S. Attention is now focused on dangerous Hurricane Maria, which at this writing is slamming the island of Dominca. For the most up to date information on Maria, Jose, and Lee visit the National Hurricane Center web site.

As Hurricane Irma gained strength I and many others were riveted to web sites, social media, and news programs tracking the progress of the storm. In this day of nearly instant communication of information it's not hard to get immersed in following the progress of a storm like this. Periodically I grabbed images and information to save in anticipation of a blog post or two about this storm. Irma and its aftermath has been well-documented so I won't rehash Irma's history here. What I would like to do is share some of the images and information I collected during the storm that you may not have seen.

The first land Irma slammed into was the island of Barbuda. Barbuda is one of two major islands that make up the Caribbean nation of Antigua and Barbuda in the middle of the Leeward Islands. Irma made a direct hit on Barbuda.

Here is the radar image from Guadalupe showing the eyewall of Irma over Barbuda at 0100 local time. Winds were likely gusting to 170 mph or more over the island.

Here is the series of weather observations from Barbuda for the two hours prior to the arrival of the eye.  Sustained hurricane force winds with gusts as high as 155 mph were recorded at this station on the southwest side of the island. Note that the CALM winds reported for the last two observations were not from being in the eye, but were due to the destruction of the anemometer.

Weather observations from Barbuda as Irma made landfall September 6.

This radar image at 1:30 a.m. local time shows the entire island of Barbuda in the calm eye of the hurricane.

Irma left widespread destruction across Barbuda. The island was evacuated after the hurricane moved on, leaving the island uninhabited for the first time in 300 years.

Irma's path then took it through the Virgin islands, producing destruction across St. Thomas, St. John, and St. Maarten.

Damage in St. Maarten.
Photo: Dutch Defense Ministry

Irma continued WNW and passed to the north of the Dominican Republic and Puerto Rico.

Hurricane Irma approaches Puerto Rico on September 6.

Irma was able to maintain its strength due to the very warm water in the southern Atlantic and Caribbean, especially the area between Cuba and the Bahamas. Sea surface temperatures in this region were in the range of 85°F to 90°F

Sea surface temperatures on September 6.

One interesting image is this one of all the marine traffic around Florida on Saturday, September 8, heading south and east. It's interesting to note the number of cruise ships.

Marine traffic near Florida on the morning of September 8.

After brushing along the north coast of Cuba on Saturday, September 9, Irma turned north toward the Florida Keys. The eye of the storm made landfall in the Florida Keys, east of Key West, around 8:00 a.m EDT, Sunday, September 9.

Radar image from the NWS Key West radar at 8:02 a.m. EDT September 10.

After crossing the keys, the eye of Irma was over open water and headed to another landfall on the Florida west coast. Irma made its final landfall near Marco Island, FL at 3:35 p.m. EDT on Sunday.

Radar image from the NWS Key West radar at 3:35 p.m. EDT September 10.

Hurricane Irma was certainly a storm of record. No doubt the name Irma will be retired. Philip Klotzbach, a tropical storm researcher at Colorado State University, compiled a list of of records and notable facts about Irma.
Josh Morgerman (iCyclone on Facebook and Twitter), a professional hurricane chaser, was in Naples, FL when Irma made landfall. He produced a video of his experience which you can view here.