Stirrings in the Atlantic

The tropical storm season has been a relatively quiet one so far this year, but  in the last two days there have been some a couple of tropical waves that bear watching.  The latest advisory by the Tropical Prediction Center has identified two areas of disturbed weather.  One is in the central Caribbean and is producing showers and thunderstorms from Hispaniola eastward several hundred miles. Upper level winds are unfavorable for much further development of this system.  To the southeast of this wave is another tropical wave about midday between African and the Lesser Antilles, and this has a better chance for development into a tropical cyclone over the next several days.

Tropical outlook for the Atlantic issued at 1:33 pm EDT on July 31, 2012

So far the have been four named tropical systems this season. Tropical Storm Alberto formed in mid-May and spun around off the northeast coast of Florida. Tropical Storm Beryl formed a few days after Alberto's demise and brushed the southeast U.S. with tropical storm force wind gusts and heavy rain in northeast Florida and southeast Georgia.  Hurricane Chris was a short-lived tropical system that developed southeast of the Canadian Maritimes on June 19. Tropical Storm Debby formed over the central Gulf of Mexico the last week of June and was a huge rain producer over the west coast of Florida and the Florida panhandle. On the morning of June 25 most CoCoRaHs observers in Hernando County, FL reported 10 to more than 14 inches of rain in 24 hours. Two CoCoRaHS observers in Crawfordville, FL (Wakulla County in the panhandle) reported more than 16 inches of rain in 24 hours!

While no one wants the damage and headaches associated with a landfalling tropical system, a good portion of the central United States would love to see a tropical system bring its moisture and rain inland to drought-affected areas. That is probably a long shot at this point. By the way, "Ernesto" will be the name of the next tropical cyclone.

More information on tropical systems in both the Atlantic and the Pacific can be found at National Hurricane Center web site.

Rain Around the Ridge

You may have noticed on this week's national CoCoRaHS precipitation maps that the rainfall pattern was generally in a large arc extending from the Rockies across the Dakotas, the upper Midwest, through the southern Great Lakes and then to the mid-Atlantic coast. South of that arc was a large area of from Nebraska and Iowa southward with no rain.   The arc of precipitation marked the northern edge of the upper level ridge of high pressure anchored over the Central Plains and Midwest. The pattern did not change much during the first four days of this week as can be seen from this animation:

National CoCoRaHs map July 21 through July 25

The 500 millibar upper air chart for July 22, 2012.

The subsiding air underneath the ridge kept the weather hot and dry. An upper level low pressure wave moving through the northern U.S. (seen just on the British Columbia coast on the map above) weakened the ridge and allowed a cold front to drop through the central U.S. today. It brought some rain to the parched Plains and Midwest last night and this morning. At the time of this post a line of storms extended from Texas to New Jersey, and severe thunderstorm watches were in effect from the mid-Mississippi Valley to the Atlantic coast.

Weekend Dust-Up in Phoenix

A haboob advances toward Yellow House Canyon near
the community of Ransom Canyon, Texas. June 18, 2009.
Credit: Wikimedia Commons

In the last post about monsoons one of the hazards listed was dust storms. Phoenix experienced a spectacular dust storm, or haboob, on Saturday, July 21. It was the first of the season for Phoenix.

Haboobs (Arabic for "strong wind") are common in arid parts of the world. In the U.S. haboobs occur in the Desert Southwest. They typically result from strong downburst thunderstorm winds. These winds spread outward from the storms, picking up loose, dry sand from the desert floor.  They often appear as a wall of dust hundreds of feet high advancing along the ground.

The haboob in Phoenix this weekend resulted from the outflows of thunderstorms that developed to the southeast of Phoenix and moved northwest.  The two radar images below show the outflow of the thunderstorms as they approached Phoenix, which likely marked the leading edge of the haboob.  It crossed through the Phoenix metro area from about 5:00 p.m. to near 7:00 p.m. local time. (Note that I was unable to find the time of the dust storm in news reports, but I did find it in the comments from our CoCoRaHS observers!)

This is the radar image from the NWS radar at Phoenix at 5;13 P.M. MST. The city of Phoenix is northwest of the radar. The white arrows point to the blue linear echo marking the outflow from the thunderstorms. The thunderstorms were moving from southeast to northwest.

This radar image shows the outflow boundary (marked by white arrows)
just about at the NWS radar site at 5:55 p.m. MST

The strong winds left almost 10,000 homes without power, and the dust reduced visibility to near zero in many areas. The dust was a nuisance and a health hazard, but it was also a boon to pool service companies and car washes in the area.

Here are some of the comments about the haboob from our CoCoRaHS observers, all from the observations on the morning of July 22. Suprisingly there were no Significant Weather Reports filed for this event!


AZ-MR-5    Sun City West 1.9 NNE    Apx 6pm Sat very strong winds with heavy blowing dust and poor visibility. Apx 8pm thunder/lightning/rain started. Apx 9:12pm VERY LOUD boom over our house with strong vibration and lightning. Heavy rain followed.

AZ-MR-25    Phoenix 4.2 NE    peak wind gust 47mph at 18:02:46 hours.

AZ-MR-68    Mesa 1.3 NNE    Haboob struck from ESE @ 1658 on 072112W? gusts < approx 50 mph. Rain began approx 1610, lasting about 20 min. (All blow and no show)

AZ-MR-72    Paradise Valley 2.8 NNW    A lot of dust and wind last evening around 6pm. To call the rainfall "trace" is a gross overstatement. There was a lttle dust in the rain guage, probably associated with a few rain drops.

AZ-MR-157    Chandler 6.6 SE    dust storm, 50+ mph winds started about 6 pm with heavy rain and thunderstorm starting at 6:30 pm, lasted until 6:45 pm, 20 degree temp drop in 1/2 hour, rain and wind stopped with gradual clearing

AZ-MR-174    Surprise 5.1 NW    The blow came through about 6PM with lots of dust and high winds followed by loud and very close lighting and thunder around 8Pm and rain toaling 0.04 inches. Lost power little after 9PM for about an hour. This AM skys are clearing, winds very light from the North, humidity 63%, temp 84 degrees.

AZ-MR-287    Surprise 10.9 NE    1.28"... 2 miles NE of Happy Valley Rd./67th Ave close to Pyramid Peak. Was not home, but could tell from where we were near 107th Ave/Deer Valley that our home was being hit hard both by the haboob and later by the thunderstorm.

AZ-MR-57    Phoenix 7.4 NE    partly cloudy. About 5:15 pm huge dust storm rolled in last night, totally obscuring the mountain from our location. Gusts of wind blew through the yard, whipping trees, then stilling. Later we would see lightning to the north, but we received no precipitation.

A freelance photographer for the Phoenix New Times took some spectacular photos of the haboob as it swept across Tempe and Scottsdale toward Phoenix. You can view these photos on the Phoenix New Times web site.

Monsoon Season

A monsoon is a seasonal change in atmospheric circulation and precipitation associated with the differential heating of land and and ocean. This differential heating, where the land is warmer than the water, results in large scale changes to the wind patterns allowing moisture-laden air to flow from the ocean sources to the land.  We typically associate monsoons with southern Asia and subtropical locations.  However, the North American Monsoon is an important mechanism bringing rain to the southwestern U.S. For many locations the monsoon accounts for 50 to 60 percent of the average annual precipitation.

The Southwest Arizona Monsoon Project (SWAMP) in 1990 and 1993 established the fact that a true monsoon, characterized by large-scale wind and rainfall shifts in the summer, develops over much of Mexico and the intermountain region of the U.S.  In 2004 the North American Monsoon Experiment (NAME) conducted in northwest Mexico and the southwest U.S sought to better describe the monsoon in North America, and increase our ability to predict it on a daily, weekly and seasonal basis. NAME showed that the weather pattern in the southwestern U.S.during the summer is not only a true monsoon, but it also affects the weather over a large portion of North America.

This map depicts the general weather pattern for the
North American Monsoon.The thermal low sets up
over the Desert Southwest,while the subtropical high
moves into the Southern Plains. The resulting wind
pattern draws moisture from sources in the Gulf of California,
the Sierra Madre mountains, and the Gulf of Mexico (green arrows).
Source: NOAA National Weather Service

The North American Monsoon (NAM) is associated with an area of high pressure, the subtropical ridge, that moves northward during the summer months and a thermal low (a trough of low pressure which develops from intense surface heating) over the Mexican Plateau and the U.S. Desert Southwest. The NAM usually occurs in five general phases, although this can vary from year to year. In general the monsoon season extends from June 15th to September 30th. The Ramp-Up phase usually occurs from mid-June through early July. The onset of the NAM occurs from late June through mid-July.  At this time winds over the southwestern U.S. shift into the east and southeast drawing moisture in at both the surface and aloft. The National Weather Service officially marks the start of the monsoon when there have been three consecutive days with the dew point above 54°F.  The peak of the NAM occurs from mid July through mid August.  The Late Monsoon phase occurs from mid August to mid September, and the monsoon Decay can occur from late August to late September.

While the monsoon brings beneficial rain to the normally parched southwestern U.S., it also produces a variety of weather hazards including intense heat, enhanced wildfire risk, flash flooding, severe thunderstorms with damaging winds and hail, lightning, and dust storms.

The North American Monsoon is a busy time for CoCoRaHS observers in Arizona, New Mexico, and southwestern Texas.  After weeks if not months of reporting zeroes they are finally able to measure something other than dust and bugs in the gauge. Check out the Daily Comments on the CoCoRaHS web site to get the observers' perspectives on the North American Monsoon.

You can learn much more about the North American Monsoon at two web sites in particular. The National Weather Service office in Tuscon, AZ has assembled an excellent series of web pages on the Monsoon in Southeastern Arizona and was the source for much of the information in this post.   There is also a web site dedicated to monsoon safety and preparedness, monsoonsafety.org.

Houston, We Have a Problem

That problem is rain, and lots of it. A nearly stationary upper level trough along the Gulf Coast combined with a steady flow of moist air from the Gulf of Mexico resulted in torrential rain in the northwest side of Houston for the past couple of days.

This is the water vapor satellite image for Thursday, July 12, 2012 at 2:45 pm CDT. The yellow dashed line marks the upper level trough, and the green arrow depicts the flow of very moist air. The orange area northwest of the trough is dry air, and the white to blue colors depict the moist air.

More than 15 inches of rain have accumulated at some locations since Tuesday, pushing several creeks and rivers to major flood levels.  Numerous homes were flooded with anywhere from a few inches to several feet of water. Some roads were still closed due to flooding late Friday afternoon.

This graph shows the river stage on Cypress Creek. The blue line tracks the observed values, and the purple dots are the forecast stages.

The National Weather Service reported that one rain gauge on the border of Harris and Waller counties recorded 10.30 inches of rain in a 10 hour period.

CoCoRaHS maps for July 12 (top) and July 13 (bottom)

 On the positive side, the three days of rain will likely put an end to the drought in southeastern Texas.

"It’s like farming in hell.”

That was a statement from Fred Below, a plant biologist at the University of Illinois in Urbana quoted in an article in Bloomberg Businessweek.  He estimated that during the heat wave last week corn yields were dropping by five bushels per day in the driest parts of the Midwest. Commodity prices are rising as yield estimates continue to tumble.

The U.S. Drought Monitor for July 10 (released today) depicts only two states not affected by abnormal dryness or worse - Vermont and Maine.  Eighty percent of the lower 48 states is affected by abnormally dry weather to exceptional drought. Severe to exceptional drought covers 37 percent of the lower 48. Both numbers are a few percentage points higher then the week before.
 

Although the focus has been on the corn crop in the last few days, that is by far from the only crop or agricultural sector affected.  Today the U.S. Department of Agriculture named more than 1,000 counties in 26 states as natural-disaster areas, the biggest such declaration ever by the USDA.

To get a feel for the scope of this disaster you have to look no farther than the drought impacts reported by CoCoRaHS observers across the country.  Here is a sampling.

Cracks in the ground are getting larger.   KS-JF-3   Jefferson County, KS   7/12/12
   
Very little irrigation water so we won't get a hay crop and will have to buy all of our hay this year. We are planning on selling some of the livestock. Horses. Also, the drought has caused wildfires which have closed roads to our area, thus stemming the flow of tourists we rely on for income. Thankfully no fires in the immediate area.  CO-JK-25 Jackson County, CO  7/3/12
   
We have reached a point that everything is so dry that fires are starting to pop up. Tuesday's fire took out over 500 acres. Fortunately no one lost Life or homes. It did get close and evacuation was necessary. This drought is at a very severe point, where we are going to see fires pop up every where. The loggers were shut down late last week, until we get some rain. Whole herds of cattle are being sold off because the producers can't feed them or they have run out of water or both. Tri-County water is in a severe shortage of water and has even mentioned that the lack of water may put some home owners with no water in an area from 105 north across to Gum Log. The fire fighting Tuesday was handy capped by the shortage of water to fight fire with. AR-PP-15    Pope County, AR  7/5/12

I've measured 1.21 inches of rain this calendar year. You can't raise a cactus on that!!  NM-RV-1    Roosevelt County, NM  7/2/12

Lawns are crisp and dry, and the ground is cracked. Plants are drying up and dying and watering is necessary for vegetable gardens. Corn in fields is showing signs of needing water. Water restrictions have not been put in place as of yet. Risk for fire is high.  PA-MT-56   Montgomery County, PA  7/11/12

Milo crop in area is averaging between 400 - 1100 lbs/acre. Normal average is 3000 - 3500 lbs/acre. Corn crop is burned up but harvest has not begun on the corn. Drip watering to keep trees and shrubs alive. Wildlife coming to water troughs near house to drink.  TX-JW-6  Jim Wells County, TX  7/11

Some friends here in the Sierra foothills are on "survival mode". Some of our wells are low because of little snow in the mountains this last winter.   CA-MP-1  Mariposa County, CA  7/9/12

Drought conditions continue to intensify from the drought which has developed back in May. Lawns across the region have gone completely dormant (brown). Larger landscape plants are constantly wilted and smaller plants are dying off. Large trees are now showing stress with color change and leaves falling off. Most streams and rivers have very low flows. OH-SN-3  Seneca County, OH  7/9/12

Watching friends and neighbors lose their crops. Ii [is] very discouraging. The field corn is turning blue and the soybeans keep losing blooms and stunted growth.  KS-SN-7  Shawnee County, KS

Some of the trees are starting to show yellow leaves. The ferns are either wilted or turning yellow. Fire danger is still extremely high. Been using leaf blowers to move the dead leaves away from the house & outbuildings.  MI-VB-2  Van Buren County, MI  7/6/12

Ground settling around lagoon knocked fence out of alignment. Pastures are very dry. Are having to feed some hay to the horses. tree leaves are starting to shrivel up. Pond and lagoon levels are dropping. electric use is up because we are using the AC's more and have to run a fan in the barn to keep the horses cool. We have been able to keep up with watering the garde and plants. Which means more electric use and wear and tear on the well pump. If we don't get significant rain Monday or Tuesday things will begin to look dire. Did have five deer grazing in my South pasture this morning which is competition for the horses.  MO-BN-20  Boone County MO  7/6/12

Corn is devastated. Cotton and soybeans are hurting. Severe fire dangers too. Showers this week have been spotty and light. Thankful for what we did get. TN-LC-7  Lincoln County, TN  7/6/12

We began chopping our corn crop for silage to feed the animals on July 1st. Two other farmers in the area have begun doing the same. The corn in our area has not produced corn cobs and will likely yield nothing. The only areas that appear to be salvageable for yields are low-lying areas near creeks and rivers.  IL-EF-13  Effingham County, IL  7/5/12

You can view all of the drought impacts reports submitted by CoCoRaHS observers on the CoCoRaHS web site. Select View Data in the top line menu, then select Drought Impact Reports in the left hand menu.

How Dry I Am...

That loud sound this weekend was that of the heat wave breaking in the eastern half of the U.S.  After days of triple digit record high temperatures in many locations, the upper level ridge shifted west and allowed cooler air to spill south into the nation’s midsection behind a relatively weak cold front. That is the good news. The bad news is that although there were some showers and thunderstorms associated with the front, there were not nearly enough to break the expanding and intensifying drought that grips much of the country.

The map on the left is the 500 millibar map upper air map (about 18000 to 20000 feet up) for the morning July 6 showing the upper level ridge planted over the middle of the country. The map on the right shows the 500 millibar map for this morning.  The axis of the ridge has retreated to the west, and cooler air from Canada is flowing into the central and eastern U.S.

 The July 3rd U.S. Drought Monitor depicted an astounding 76 percent of the lower 48 states in Abnormal Dryness, and 36 percent in Severe Drought or worse.  This is a critical time for agriculture in the corn and soybean belt, as corn is in or approaching the pollination stage. The lack of water and the heat will take a toll on corn yields, and grain prices are already rising as the condition of the crop worsens.  Soybeans can tolerate more heat and have some more time before they reach a critical period of development in August.

In an ironic twist, the High Park fire area west of Fort Collins, CO received two to four inches of rain this weekend, resulting in flash flooding. Debris from the fire was washing into piles creating debris dams, further exacerbating the flooding.  Two weeks ago firefighters were dealing with the wildfire. This weekend they were pumping basements flooded by the rain.

With drought so dominant at this time, we need and appreciate your daily rainfall reports, especially those reports of ZERO. The spotty nature of showers and thunderstorms mean that some locations can receive inches of rain, while a few miles away there's not enough to settle the dust.  

Davidson County, TN rainfall for the morning of July 9, 2012.  Nashville is located near the red dot.

 "0.00" is a measurement- it explicitly states that you measured no rain. No report, on the other hand, leaves everyone guessing.  There have been an impressive number of CoCoRaHS observers regularly reporting rainfall, zero and otherwise.  Below is the map from June 26 when the central U.S. was dry as a bone.

On June 26 there were 9,561 total reports, of which 7,061 were zeroes (gray dots).

So remember, "Be a Hero - Report Your Zero!"

The Catch - Important request at a critical time of year

Dear CoCoRaHS rain gauge team
 
A belated 4th of July greeting.  It was odd here to have no fireworks 
show last night (I know the same was true in many other areas of the 
country).  But it simply was not appropriate given the severity of heat, 
drought and wildfire potential.  There were scarcely any backyard 
firecrackers, either -- a clear sign of public recognition of the 
situation.   Nevertheless, we were able to celebrate with friends and 
family some of what makes this such a great country.  I, for one,  gave 
thanks that we live in a country where so many people love to volunteer 
their time and resources to accomplish important things together.  Our 
mutual rain gauge program (CoCoRaHS) is one small example of that.
 
 
We need more rainfall data
 
We are currently experiencing extreme heat, extreme drought, extreme 
storms, and local floods in various parts of the country.  In all my 
years in this field, there have only been a few others where there was 
this much public, media and commercial interest and concern over 
precipitation (or lack thereof) in so many parts of the country.
 
 
Does it really matter?
 
Yes indeed!  Our CoCoRaHS rainfall reports are a huge and valued 
resource to weather and water forecasters, agribusinesses, researchers, 
teachers, resource managers and many more.  We already have great 
volunteers all over the country, but rainfall varies so much that we 
still aren't tracking it well in many places.  We need more gauges in 
more places.
 


Look at today's (July 5) maps  http://www.cocorahs.org/Maps/  In Wake 
County, NC precipitation ranged from 0 to over 3" in just a few miles.  
Likewise, check out Pima County, AZ (0.05" - 4.32"),  Real County, TX 
(0.19" - 3.74"), Pasco County, FL (0 - 2.95") and Oakland County, MI 
(0.13" - 2.03")  We were able to pinpoint these remarkable local 
variations because we were fortunate to have many volunteers in each of 
those counties.
 
For much of the country we only have one or two reports per county. 
Despite good progress this year, we still have a few hundred counties 
nationally with no active reporters.
 
And now is when it matters most.  This is the time when rainfall is most 
locally variable -- and this is the time when drought is having the most 
acute impacts over the largest areas.  It is also the time when the most 
intense rains tend to fall -- from localized summer thunderstorms.  As I 
write, I am recalling 15 years ago (can't believe that much time has 
passed already) when we had 14" of rain right here in Fort Collins -- 
but other parts of town had less than 2".  If we had volunteers then 
reporting their rainfall and sending in "Significant Weather Reports" 
during the heaviest rains, there is some chance we might have helped 
saved lives that night.  This same situation repeats itself every year 
but in different places.  Our rainfall reports really can make a difference.
 
 
You can help.
 
Here are some ideas and suggestions
 
1)  Many of us are already helping.  Thank you so much for checking your 
gauge and sending in your reports.  Please know, your efforts are 
appreciated.  Also know that the earlier in the day you submit your 
report (ideally by 9 AM), then the more weather and water forecasters 
will be able to use your data -- both when it rains and when it 
doesn't.  We're working on smart phone data entry that will make this 
easier for some of you.
 
2)  Some of us signed up but have never gotten started.  If this sounds 
like you, PLEASE begin now.  This alone could add several thousand new 
observers to the network and that would be AWESOME. It's really easy (at 
least in summer).  If you have questions or need help getting started, 
just send a quick e-mail to info@cocorahs.org    or contact the local 
CoCoRaHS volunteer leader (coordinator) for your area listed here: 
http://www.cocorahs.org/Content.aspx?page=coord   If you were very 
interested in reporting rainfall but could not join CoCoRaHS because of 
the ~$30 cost of the rain gauge, please let me know.  We have some 
generous sponsors who are helping in these situations.
 
3)  A whole lot of us signed up, got started, but didn't stick with it 
for a whole variety of good reasons.  If this sounds like you == then 
please consider trying again.  It really only takes a couple of minutes 
a day  -- and we're very flexible (report when you are able, and don't 
worry about it when you're away or too busy).
 
4)  Help recruit new volunteers!
      -- Tell your friends and family, especially those who live in 
areas where we have few volunteers.  Ask with some urgency and say 
things like  "CoCoRaHS really needs your help"
      -- If you have contacts at local newspapers, magazines or TV 
stations, see if they would put out a story about CoCoRaHS and how local 
citizens can help.
      -- If belong to organizations such as Rotary or Lions clubs, 
Master Gardeners, Master Naturalists, Conservation Districts, Watershed 
Stewards, Amateur Radio, and any of a large number of similar 
organizations, tell them about CoCoRaHS and invite others to join.  
Spread the word however you can.
      --  Make use of the CoCoRaHS short animation to quickly describe 
who we are and what we do
  http://youtu.be/M5-sXXg9M30
      --  If you want to give more history about how CoCoRaHS started, 
then view this slightly longer video
http://youtu.be/yHmz5IyjV80
 
5)  Many of us have had to retire from CoCoRaHS.    Thanks, and we hope 
you elect to continue to be a part of our family even if you can't take 
measurements any longer.
 
 
Other CoCoRaHS News
 
The Blog is back http://cocorahs.blogspot.com/
 
The CoCoRaHS water cycle animation is a hit.  



View the Water Cycle video here.
Have you tried CoCoRaHS Facebook? http://www.facebook.com/CoCoRaHS
 
 
Farm News -- Good and sad
 
Despite the heat and drought, we're getting a decent crop of apples from 
our early tree. The apples (and it's always been this way) like to fall 
off the tree about a week before they are ready to pick or eat.  But if 
we get them before they're
too bruised, they make a fine apple sauce.  The last couple of weeks the 
tree has been full of Flickers -- a flock of them.  I never knew that 
flickers flocked, but we've been told they were driven out by the fire 
in the foothills and have been congregating at local water holes (like 
our tree).  I don't now if this is true, but it sounds good.
 
Our goslings are growing up so fast -- fun to watch at this stage of 
life.  Despite the heat, the chickens are still laying quite well -- 
plenty of fresh eggs/
 
Several of you have asked about Angel (our beautiful female Great 
Pyrenees who added many stories to our lives these past few years). 
There's been so much going on and I just haven't felt like talking about 
it.  She left this world a few weeks ago -- hopefully for greener 
pastures.  My plan to show a picture of us together and recount a few 
good memories in the CoCoRaHS Blog soon.
 
 
In closing
 
Nice little thunderstorm this evening -- not enough to make a flood or 
end a drought, but for now the air is fresh and cool -- a great relief 
after many days of heat.  Thanks for your interest in CoCoRaHS.  It's a 
pleasure working with all of you.
 
 
Sincerely,
 
Nolan Doesken
Colorado State University

Hotter Than a Firecracker

Much of the nation will be experiencing hot, humid summer weather on this Fourth of July.  Maximum temperatures will exceed 90°F in most locations east of the Rockies, and many locations in the nation’s midsection will see temperatures in excess of 100°F. 

Forecast maximum temperature for July 4, 2012

 

At 11:00 a.m. EDT the Midwest and mid-Atlantic region from Delaware to South Carolina were already at 85°F and higher, and the dewpoint ranged from 65° to greater than 70°F. 

Temperature (L) and dewpoint (R) at 11:00 EDT July 4, 2012

The heat index (apparent temperature) represents what it really feels like when humidity is factored in with the actual air temperature. The heat index today could reach close to 110°F in many locations – anything 105°F or higher is dangerous.  Excessive heat warnings and heat advisories have been issued for much of the Midwest, parts of the mid-Atlantic, and in western Alabama.

Forecast heat index for 5:00 p.m. EDT July 4, 2012

Heat advisories (orange) and excessive heat warnings (pink) are in effect for most of the central U.S.

On a day when picnics, parades, and fireworks are tradition, the danger posed by the heat and humidity is very real. Believe it or not, heat is the number one weather-related killer in the United States, resulting in hundreds of fatalities each year.

If you are going to be outside during hot weather know how to stay safe, and learn the warning signs of heat cramps, heat exhaustion, and heat stroke.  Information on heat waves and how to cope with them can be found at the following links:

• Heat-related Illnesses – Do You Know What to Do? - American Red Cross  
• Heat Wave Safety Checklist – American Red Cross
• Heat: A Major Killer – National Weather Service 

Have a safe and happy 4th of July, everyone!