From the ABC 7 Weather team

Archive for July 2012

D.C. Records: July 2012 Second Hottest Month In Weather Records

August 1, 2012 - 05:00 AM

July 2012 will go down as the 2nd hottest month in weather records.  The month finishes with an average of 84°.  That's 4.2° higher than the July average.  The hottest month still goes to July 2011 with an average high of 84.5°. 

Even though the month wasn't the hottest, it sure came close.  Only half a degree difference between this year and last year.  July 2011 takes the gold for the hottest month on record, but July 2012 takes the crown for the number of days at 100° or higher.  This July had 7 days 100° or higher - in fact, 4 of them fell on consecutive days, which ties the most number of consecutive 100° days set back in 1930. 

July 2012

July was hot, but also dry.  The two often go hand in hand and this July was no exception.  Most of the region remains under abnormally dry conditions or a moderate drought.  D.C. did get a few summertime thunderstorms that provided some needed rain, but the monthly rain was, once again, below average - nearly an inch below.  Here are the yearly rainfall deficits, as of July 31, 2012. 

2012 D.C. area yearly rainfall totals and departures

July was not only above average and hot in D.C., but across the Southern Plains and much of Eastern states.  As of July 30th, take a look at some of the monthly average temperature departures across the nation (thanks to intern James Stanley for finding out these numbers!). 

Indianapolis, IN: +8.5° - 28 days of 90° or higher

Topeka, KS: +7.4° - 30 days 90° or higher 

Oklahoma City, OK: +3.5° - 100° or higher since July 18th

Chicago, IL: +7.2° - 18 days 90° or higher

August 2012 in D.C. will start off hot, but no record breaking temperatures through the first week. 

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TIMELAPSE: Storms & Fantastic Sunset All In One

July 31, 2012 - 08:34 PM

What an eventful last day of July in the Nation's Capital.  The thermometer climbed to 90° on the 31st making it the 22nd day of the month at 90° or higher.  There were also summertime thunderstorms that made for some neat sky views.  Take a look at this timelapse from the WeatherBug camera on top of the ABC7 studio looking West.  Notice the dark storm clouds and rain falling in the distance and the storms moving North.  You have to see the sun come out at the end.  Enjoy!


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Lightning: Awareness and Safety

July 28, 2012 - 03:00 PM

You've heard it before - "When thunder roars, head indoors".  It seems simple, but unfortunately, some people take too long to get into a safe space when thunderstorms approach.


Lightning, although neat to look at in photographs, is extremely dangerous.  To learn more on the science behind lightning, here's a great link to check out.  Sadly, lightning has already caused 17 deaths in 2012 in 13 states.  With the recent high heat and humidity, the middle and Eastern U.S. has seen numerous severe weather outbreaks.  Often, a lot of lightning is associated with these summer storms.  Not only does lightning occur in the summer, but can happen in every month and in every state.  Here's a map of lightning deaths by state.  Florida has the highest lightning fatalities.


Lightning fatalities can be avoided if people follow this motto - "When thunder roars, head indoors".  It's especially important to remember in the summer months when people are outside enjoying the warm days.  Even if it isn't raining and doesn't appear there's a storm where you are, still go inside!  If you're close enough to hear the thunder, you're close enough to get struck by lightning.

If you're interested in other lightning phenomena, check out NC8 meteorologist Devon Lucie's blog on Ball Lightning.  Be safe!

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A timelapse worth watching (VIDEO)

July 27, 2012 - 08:00 AM

The clouds at sunrise were originally rainmakers over the Ohio Valley, but for us they just made for a colorful sunrise. The sun rose at 6:05 a.m., and we have 14hr and 18 mins of daylight today in Washington, D.C. I love our WeatherBug rooftop camera, and it's easy to see why.  By the way, you can always view the feed here along with many other HD cameras across the Washington area.

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LIVE BLOG: D.C. Severe Weather Possible

July 26, 2012 - 08:45 PM

11:27PM: Eileen Whelan Even though the initial threat for severe weather is done before midnight, I think there could be another round to move into the area overnight (between about 3-6AM).  The radar image below shows the area of storminess we'll watch overnight, as it tracks East.  The big question is whether the storms will hold together.  Regardless, they do not look likely to be severe. 

Storm Scan as of 11:25PM

11:02PM: Eileen Whelan The threat for severe storms is done tonight.  A few showers/rumble of thunder are still possible, but overall, everything is quieting down.  Severe thunderstorm warnings have been canceled. 

10:34PM  Bob Ryan Once cell south Manassas moving toward Dale City.  That's about it.  Watch being gradually dropped west to east  with time

 10:07PM - Devon Lucie  The SEVERE T'STORM WARNING for Loudoun-Fauquier-Prince William COs has been cancelled as the thunderstorm drastically dropped in its intensity.  As per the SPC discussion below, I really think our severe threat is very slim now through tonight.



10:00PM - Devon Lucie First SEVERE WARNINGS have been issued for the D.C. Metro: Loudoun-Fauquier-Prinice William COs until 10:30PM.




9:26PM - Devon Lucie  The SPC has issued a new mesoscale discussion for our area.  My quick summary:  severe storms still possible, but likelihood of very strong winds and/or a widespread severe event is doubtful. 

Courtesy: NOAA/SPC


9:00PM - Devon Lucie  Storms have really slowed up over the Appalachians.  Take my earlier D.C. metro times and slow them down by an hour:  NW suburbs around 10PM - D.C. about 10:30-11PM - E suburbs around 11:30-midnight.  A lack of severe warnings too... good news.

8:45PM: Storms are starting to fire up north of Baltimore and another line of storms is stretching from Hagerstown and Southwest through Martinsburg.  These storms will generally track, very slowly, towards the East.  The greatest threat will be localized flooding and strong wind gusts.

Live Super Doppler as of 8:40PM

7:45pm update: - Devon Lucie  My latest storm tracks put strong/severe t'storms to the west/northwest suburbs by 9PM - D.C. proper by around 10PM - and the east suburbs (Prince Georges & Anne Arundel counties) by around 11PM.

6:05pm update: - Devon Lucie 
A SEVERE T'STORM WATCH has been issued for the entire region effective through 1AM Friday morning.  The main threats from these storms are possible damaging winds over 58mph, and hail.

 5:40 PM
Now a 45% Chance severe storms with damaging winds later this evening across northern Marylaqnd


5:30 pm Update - Bob Ryan Reports of tornado damage Elmira, NY and people trapped in cars.  Strong storms SW PA-eastern NYS but so far nothing developing DC area.  Record 7th 100° Day this July

4:45pm update:  The Storm Prediction Center (SPC) has put the D.C. region under a SLIGHT RISK for severe weather through Friday morning.  Already, a significant outbreak of severe weather is occurring in Pennsylvania and New York. 

It's the ABC7 weather department's thinking that our best chance for storms comes after midnight tonight.  There is a very slim chance that we might see storms fire up over the next few hours, but we feel that chance is very low.  The SPC has discussed the possibility of this storm development too.  Here's a glance of the graphic and part of their discussion from about 3pm EDT.  To sum up:  the risk of storm development is marginal in the D.C. region through the early evening hours.

Courtesy: NOAA/SPC

I think it's storms over Ohio at about the 4:45pm EDT hour that will have an impact on the D.C. re


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This Weekend's Beach and Boating Forecast

July 26, 2012 - 06:15 PM

Atlantic City, NJ
Saturday has 50% chance of thunderstorms, with temperatures in the upper-80s. Saturday evening will have 40% chance of thunderstorms; temperatures will drop down into the low-70s.

Sunday, however, will only have a 20% chance of thunderstorms, and temperatures will only reach the upper-70s. The temperatures will just drop a few degrees into the low-70s, and the skies will be mostly clear.

Atlantic Beach Forecast July 28 & 29th

Rehoboth Beach, DE / Ocean City, MD / Virginia Beach, VA
Saturday has a 40% chance of showers, with temperatures in the upper-80s to low-90s. However, the evening will bring a 40% chance thunderstorms, and temperatures will drop off into the low to mid-70s.

There is a 30% chance of thunderstorms on Sunday, while temperatures rise to the mid to upper-80s. On the other hand, Sunday night will have mostly to partly-clear skies and temperatures will sink into the lower-70s.

Hatteras, NC
Saturday will start off with temperatures in the low-90s, and a 40% chance of thunderstorms. The evening will drop down into the upper-70s to low-80s, with a 30% chance of thunderstorms.

Sunday will reach the upper-80s and only has a 20% chance of thunderstorms. Sunday night, temperatures will only drop into the mid-70s, but has a 30% chance of thunderstorms.

If you are heading to the Chesapeake Bay, this weekend looks nice as well.

Chesapeake Bay Forecast July 28 & 29th

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D.C. Weather: Record challenging heat today but relief is not far off

July 26, 2012 - 10:31 AM

Within 24 hours, our weather has done a complete 180. In one day, we're going from blue skies, low humidity and seasonable highs in the upper 80s to humid and perhaps record-challenging heat.

What happened?

In short, a warm front lifted north through the region overnight, putting us back in the sticky, hot, and unstable air.

Our forecast for Thursday has us topping out around 100 degrees, which puts our area records in jeopardy of being tied or even broken. The record that has the best shot of being broken, in my opinion, would be Dulles with a record high of 98.

BWI Marshall also has a pretty good chance reaching or exceeding the current record of 101, but Reagan National will be the hardest to break or tie, with 103 degrees the current record high.

Even though clouds blocked sunshine in many places this mornng records are still within reach. Given that we are going to see plenty of sunshine during the peak heating of the day, I am not going to rule out the possibility that all records could potentially fall Thursday.

Record highs aside, if we reach the 100 degree mark, it will be the 8th time we have done that in 2012. If you are hoping for an afternoon/evening shower or storm to cool you off, your chances might be few and far between. Thunderstorm activity will be widely separated in nature and will center mainly north and west of town.

I should also mention that while the thunderstorms will be widely separated, the potential is there for strong to severe storms.

Rain chances will increase Friday and Saturday as a cold front slowly pushes through the region. Cooler and less humid air will return by Sunday into early next week as high pressure builds into place.

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D.C. Heat & Humidity Comeback: Severe Storms, Too?

July 26, 2012 - 05:00 AM

Sunny, Seasonable, and Reasonable (I have to quote Bob Ryan on that clever rhyme).  Those three words pretty much sum up D.C.'s Wednesday forecast.  Not only a brilliant blue sky, with a few high, thin cirrus clouds, but highs about average, with extremely low humidity.  Well, I hope you were able to enjoy it, since the late July heat and humidity will return with a vengeance to round out the work week.  It was nice while it lasted, right?  Here's a clear view of the city from atop the WJLA/NC8 building late Wednesday afternoon.  Notice how clear it is!  Usually we look at a pretty hazy view of the city.

Washington WeatherBug Camera - June 24, 2012

High temperatures Thursday will climb well into the 90s with a few triple digit readings possible, too. 

Forecast Highs Thursday, June 25, 2012

Now we all remember some of the days, this summer, when highs were in the upper 90s and low 100s and  we got rocked with severe storms.  I'm sure most people still vividly remember the infamous D.C. Derecho.  So, is there any possibility of another Derecho, or at least the threat for severe storms, with this next bout of intense heat and humidity? 

Yes.  Do I think we're in for another Derecho in D.C. tomorrow?  No.  Now I will say that isn't out of the realm of possibility for points North and West of D.C. - especially in Pennsylvania and Ohio.  Take a look at the Storm Prediction Center's Convective Outlook for Thursday, July 26.

Storm Prediction Center: Convective Outlook

The greatest risk for severe storms and damaging winds will be North and West of the WJLA/NC8 viewing area.  Extreme Western Maryland and points West of the Blue Ridge will be the most likely to see storms develop.  The storms will develop ahead of a front that will move out of the Upper Midwest and into the Mid Atlantic and Northeast Thursday and will eventually slide offshore by late Friday.  That means there will be enough lift and energy to support storm development over the next two days.  Here's one simulation of the atmosphere on Thursday.


We DO NOT anticipate another D.C. derecho this week, but it may not be out of the question for people in Pennsylvania and New York.  The StormWatch7 weather team will monitor storm development and will keep you informed.  On twitter?  Want to receive ONLY severe weather alerts?  Follow StormWatch7.  Now is also a good time to see if you're prepared when severe weather strikes.  Here's a great list of items you should have on hand in the event of severe weather and other emergencies. 

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Severe weather for the D.C area (Live Blog)

July 24, 2012 - 01:21 PM


Twitter: @StormWatch7  |  @alexliggitt  |  @adamcaskey  |  @BobRyanABC7  |  @Chrisnaille  |  @DougHillABC7  |  @SteveRudinABC7


6:15PM Update Bob Ryan here - All the strongest cells now well south of DC area and severe watch for some of of the area has  come down for areas just north of DC.  Most area should come down soon

5:49PM Update The storm in Montgomery warning canceled!  Rapidly weakening but still some  gusts Will miss DC Watch still out until 8PM

5:27pm Update: A Severe Thunderstorm Warning is in effect for Montgomery County until 6pm. Damaging winds will be possible in this storm as it comes southeast along I-270.

4:52pm Update: Check out our Frederick Camera here on our website. Good rain going on there! Check out some of the other HD camera images while you're there.

4:26pm Update: A Severe Thunderstorm Warning is in effect for Frederick County in Maryland until 5pm. Damaging winds will be possible in this storm. Please be safe but if you see any wind damage, report it to us! Comment below!

3:54pm Update: Spotsylvania County southwest of Fredericksburg in Virginia is getting crushed with a strong storm and A LOT of lightning. There have been 555 lightning strikes in that storm in the past 10 minutes. Take cover now! Check out Doppler Above.

3:41pm Update: Another hour and another look at the satellite which is showing a ton of clouds over the D.C. Metro from the storms located over Winchester and Romney. There are a few storms north of the Mason-Dixon still, but unless D.C. gets some clearing in a hurry, severe weather shouldn't be a big issue. We'll continue to monitor.

The storms we are continuing to watch are located from around Gettysburg northeast to York, PA. These will move into Washington, Carroll and Baltimore Counties over the next 30 minutes or so.

2:54pm Update: We are currently looking at some clearing along the Mason-Dixon and north ahead of those new cells in Pennsylvania. This may allow for more heating in the D.C. area which could lead to severe storms later this afternoon and evening closer to the D.C. Metro.

2:48pm Update: Hardy County in West Virginia had a severe weather report come in saying,


This is where the tornado warned storm went through earlier today. No reports of a funnel or tornado but interesting enough that this may be looked at later this week by the NWS.

1:41 p.m. Update: Here is a good look at the Mid Atlantic Radar Loop which shows much of the action west of D.C. over Kentucky and West Virginia. We will be closely watching the cells developing over Pennsylvania as they will head towards our region later this afternoon and evening.

1:32 p.m. Update: A severe storm with some rotation will cross the I-81 corridor in the next few minutes just south of Woodstock, VA in Shenandoah County. The storm appears like it just weakened some but will have strong winds and very heavy rain. It will pass very near Mount Jackson and then head towards Luray and Stanley. A Tornado Warning continues through 1:45 p.m.

1:24 p.m. Update: A Severe T-Storm Watch is in effect until 8 p.m. for the entire D.C. area. Storms will have the potential of damaging wind gusts and large hail. The discussion for the watch from the Storm Prediction Center can be found here.

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Sally Ride: NASA's First U.S. Woman In Space Dies

July 23, 2012 - 09:00 PM

June 18, 1983 - Sally Ride, aboard the NASA Space Shuttle Challenger's STS-7 mission, becomes the first American woman to soar into space. 

July 23, 2012 - Sally Ride, age 61, passes away after a 17 month battle with pancreatic cancer, but leaves behind an incredible legacy. 

Dr. Sally Ride is a pioneer for women and not only made her mark, in history, as the first U.S. female in outer space, but also went on to teach and motivate young women to pursue careers in science, math, and technology. 

Ride in the pilots chair monitoring the control panels on the shuttle Challenger, June 1983

NASA Administrator Charles Bolden said, in a recent statement,  "Sally Ride broke barriers with grace and professionalism – and literally changed the face of America’s space program".  Ride went on to complete a second shuttle flight in 1984, which would end up being her last.  She was assigned a third flight, but that one was canceled after the Challenger accident in January 1986. 

STS-7 Crew - First U.S. Female & First 5 Person Crew To Head Into Space

Ride left NASA in 1989 and went on to pursue her other passion - teaching and inspiring young women.  Ride joined the University of California San Diego as professor of physics and director of California's California Space Institute in 1989.  Later, in 2001, Ride founded Sally Ride Science to create quality programs and products that "educate, entertain, engage, and inspire".

Ride working alongside Anna Fischer: Fellow member of the 1978 astronaut class

Here's where you can read Dr. Sally Ride's full biography.  Ride broke a gender barrier and showed everyone the sky is not the limit. 

Here's to an incredible life and legacy.  Godspeed, Sally Ride.

Three days before the launch, Ride on a T-38 jet bound to NASA's Kennedy Space Center in Florida

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July in Washington: A Plethora of Heat Records

July 22, 2012 - 04:40 PM

Barreling through July on a record hot pace, it's hard to believe we’ve swung the pendulum just the opposite way to record cool weather, too, not once but twice!

The average monthly temperature at Reagan National Airport in July is 84.7 degrees, which is a whopping 4.9 degrees above average. This is on par to becoming the hottest July on record in the nation’s capital (see below). What’s even more… this includes two days (Saturday included) with rock bottom “cold” temperatures amidst a sweltering month. The following includes all of the daily record temperatures set during the month so far:

Record Coldest High Temperatures
July 21: High temperature of 71 degrees defeated the coldest high temperature of 74 degrees

Record Warmest Low Temperature

July 2: Tied for the record high minimum temperature of 73 degrees

July 18: 80 degrees defeated the former record of 79 degrees

Record High Temperatures
July 7: 105 degrees defeated the former record high of 102 degrees set in 2010 and tied for the second warmest high temperature of all-time in Washington.
July 8: 102 degrees defeated 100 degrees set in 1993
July 5-8: Four in a row 100 degree days ties the record for consecutive 100 degree days set in July 1930

Now, with only nine days left in the month, Washington could easily have the warmest July on record.

Record Warmest July at Reagan National Airport (average temperature):
1. 2012 (84.7 degrees so far)
2. 2011…84.5 degrees
3. 1993 and 2010…..83.1 degrees
4. 1999…..83.0 degrees
5. 1987…82.5 degrees
6. 1872….82.3 degrees

Temperatures will climb above average early next week before a front returns them back to near average by the middle of the week. Looking ahead through July 31, temperatures will likely trend above the average high of 89 degrees but no major heat waves like we saw so far this month are in the offing.

Stay cool and for the latest forecast tune to WTOP Radio, watch ABC7 News and visit the website.


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StormWatch7 Severe Weather Alerts on Twitter

July 20, 2012 - 08:20 PM

On Twitter?  Looking for the perfect follow to give you the most timely severe weather alerts... and ONLY severe weather alerts for the ABC7 and NewsChannel8 viewing area?  Well, look no further.  StormWatch7 is the twitter handle to follow. 

The alerts are updated any time the National Weather Service issues a severe thunderstorm warning, flash flood warning, or tornado warning.  It will do the same for winter storm warnings and other severe winter events.  It won't clutter your twitter feed, but will only give you the most pertinent weather warnings. 

StormWatch7 Twitter Account
So, get on twitter and follow StormWatch7! If you're also looking for a good weather app to track possible severe weather and keep updated with the local forecast, click here to download the FREE the StormWatch7 weather app.

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This Weekend's Beach and Boating Forecast

July 20, 2012 - 06:15 PM

Ocean City, MD / Rehoboth Beach, DE

Saturday will be overcast and have a 50% chance of showers during the day; temperatures will peak in the upper-70s to low 80s. In the evening, temperatures will be dropping down to the low-70s and upper 60s, with a 30% chance of rain.

Sunday will be slightly warmer in the low to mid-80s but only have a 20% chance of showers during the day and into the night. Temperatures will drop into the mid-70s overnight.

*If you click here, you can check out what it looks like at Ocean City.

**Also, here is the camera for Rehoboth Beach.

Weekend Beachcast

Atlantic City, NJ

Saturday has only a 30% chance of rain showers throughout the day and the night. Highs will be in the low-80s and lows in the upper-60s.

Sunday will have partly sunny skies, with temperatures in the low-80s, but only dropping down into the low 70s at night. There is a 20% chance of showers and thunderstorms in the evening, so be aware of that during your late night beach and boating activities.

Virginia Beach, VA / Nags Head, NC

On Saturday, there is a 70% chance of showers with heavy rain at times; temperatures will be in the mid to upper-80s. There will be a 50% chance of showers in the evening as well, with temperatures dropping off into the low to mid-70s.

Sunday temperatures will be the same as on Saturday, in the mid to upper-80s, and have a 50% chance of thunderstorms all day and night, with lows in the mid to upper-70s.

Hatteras, NC

Saturday has a 50% chance of thunderstorms, with highs in the mid-80s and lows in the mid-70s.

Sunday will be slightly warmer in the mid to upper-80s and has a 50% chance of thunderstorms. During the nighttime, there is a 30% chance of thunderstorms, but temperatures will only be as low as the upper-70s.

Here's a look at what you can expect near the Chesapeake Bay:

Weekend Chesapeake Bay Forecast

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Flash flooding possible for the D.C. area Friday

July 20, 2012 - 06:45 AM

Yesterday brought with it more storms with flooding through the D.C. and Baltimore Metro areas. Unfortunately, there is another potential for flooding today as an area of low pressure advances from the west. Not only is there the chance for flooding, but also some isolated severe weather, as some of the storms may also have damaging wind gusts. With the already saturated grounds from recent storms and weakened trees from the derecho a few weeks ago, it may not take as much now for trees to fall.

Check out the thunderstorms that came through the region last night. I remember looking at them on Doppler Radar before heading to bed early and thinking they were definitely going to reach D.C. Sure enough, 10pm rolls around and it was rocking and rolling outside my bedroom! Here's a picture I snapped of the line last night. (On a side note, I went to bed at 8pm as I had to wake up around 3 a.m., just sayin..)

Line of thunderstorms last night

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Storms Crossing The Chesapeake Bay: TIMELAPSE

July 18, 2012 - 11:45 PM

July 18, 2012 marks D.C.'s 7th day, in 2012, at 100° or higher!  With the July heat (and relief on the way) comes some nasty storms.  Take a look at this timelapse from one of our WeatherBug cameras in Stevensville, MD. The camera is looking West, across the Chesapeake Bay.  Fast moving storms and then a pretty sunset. 


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Severe weather heading to the D.C. area (Live Blog)

July 18, 2012 - 03:30 PM

Check out Live Super Doppler 7 Here

Get immediate updates about warnings on Twitter: @StormWatch7

Send any pictures and video to or using our Weather App.

6:15PM Update:  Everything fairly quiet now around the Metro area.  Few storms still firing up West of the Blue Ridge, but otherwise the main threat for severe weather is over.  Thanks for keeping updated through our live blog!

5:58PM Update:  Lot of lightning with the strongest storms over the Bay Bridge and now onto the Eastern Shore. Take a look at all those lightning strikes... that's a total of 478 in 5 minutes!  Dangerous!

Latest 5 Minute Lightning Strokes as of 5:47PM

5:55PM  Bob Ryan here: The strongest storms continue to move well east of DC over the Bay and into the Eastern Shore.  There is still the risk of some local flash flooding but the storms are pretty much over for the DC area.  Tomorrow very humid but still hot, near 95° and the risk of thunderstorms again by mid-late afternoon



5:40PM:  Nasty storms over Annapolis and crossing over the Chesapeake and Bay Bridge.  Blinding rain, gusty winds, and possibly small hail.  Very dangerous to be driving in right now.  Strong storms over in the D.C. metro area now. 

Latest live Doppler - 5:40PM

5:15 PM Update Bob Ryan  Strongest storms with still threat of 1" hail now into Anne Arundel County.  Downtown DC almost 2" rain in one hour so reason for Flash Flood warning until 7PM  Other severe warnings in metro area until 5:45 PM.



5:03 PM Upate:  Those slow moving storms over the District, Montgomery, and Prince Georges counties have prompted a FLASH FLOOD WARNING until 7PM.  Some spots have seen between 1 and 2 inches of rain in the past hour, so be very cautious on the roadways and don't drive through standing water. 

5:00PM Update  Bob Ryan here New warnings for the line of strong thunderstorms moving through Prince Georges and Ann Arundel County.  History of hail and plenty of cloud to ground lightning so power outages likely.  These storms move into the Bay next 1-2 hours



4:35PM Upate:  Current storms over Southern Montgomery County, Northern D.C., Prince George's, and Anne Arundel counties now under a Severe Thunderstorm Warning until 5:15PM.  VERY heavy rain, lots of lightning, and even some reports of hail.  Be safe out there!

Live Super Doppler as of 4:35PM

4:24pm Update:  Severe warning for DC and immediate area until 5PM threat from some already damaged trees with some wind gusts and hail reported in Bethesda.  Cells moving very slow and with heavy rain  



4:08pm Update  Cells are developing now over metro area  Report of small hail around Bethesda  Slow movement and very heavy rain with these slow movers  



3:53pm Update: Bob Ryan here  Thunderstorm firing up right now around Bethesda all these cells moving fairly slow so dump heavy rain.  Strongest still in Frederick County MD



3:31pm Update: A few rogue storms are popping up closer into the city though they are still rather weak at the moment. Still enough for a few lightning strikes.

3:26pm Update: There have already been a few reports of trees down from the National Weather Service through Frederick Co., VA. There are some gusty winds in the line moving towards Frederick now, be sure to get inside to a safe place.

3:19p Update: The strongest storms are heading into Frederick and Carroll Counties in MD and will affect Westminster, New Market, Manchester and Green Valley. These will also head towards the City of Frederick as well in the next 20 minutes or so. Be ready for damaging winds and a lot of lightning in these storms. A Severe T-Storm Warning is in effect through 4pm.

3:16pm Update: A Severe Thunderstorm Watch is in effect for the entire D.C. Metro until 9pm tonight. Stronger storms will be capable of producing damaging wind gusts and possibly some large hail. There is also the potential for some flash flooding as these will be relatively slow moving storms.

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Global Warming and the Higgs Boson

July 18, 2012 - 05:10 AM

OK I admit I picked this title to get your attention. But there is a bit of a parallel between the headlines of July 4 of the “discovery” of the Higgs boson, global warming, climate and environmental change and the way science works and how I hope how we learn. Indeed after the announcement of the discovery, Washington then had 4 100° days in a row and the temperature reached 105° July 7. A coincidence you say?? Of course                                                                                            



 Peter Higgs is a theoretical physicist who with other scientists proposed a theory in 1964 for the existence of what would be known as the Higgs boson or Higgs particle. It was a mathematical fundamental concept or idea if you will. A theory. The theory of global warming is much older than Peter Higgs theory. A Swedish scientist Svante Arrheniis in the late 1800s examined the role that carbon dioxide plays in climate change (everyone agrees that the climate and earth’s temperature have always been changing) and his theory was that a doubling of CO2 would raise the earth’s temperature by about 10°. In the 1930s another pioneering scientist/engineer G.S. Callandar published a number of papers on the theory. All this well before Peter Higgs  theory and the recent “discovery" of the Higgs Boson. What the heck is the connection? Well experimental physicists haven’t actually seen the Higgs particle. Just the footprint of the evidence of the particle. This is the graph from the huge Hadron atom smasher in Switzerland at CERN and the statement about the Higgs being found "We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV."  No one had actually seen the Higgs particle but the little bump in the graph below is its "footprint" of where it should be, when atomic particles are accelerated to tremendous speeds and energy and crash into each other


 That is how science works - from theory to observations and experiments. See any footprints of human influence on the night sky below? 


Nasa Image
How about our influence on land in this satellite image from 400 miles above us.


See New York City, an urban footprint? Anthropogenic changes in land use?  Even run off in the Hudson River after Tropical Storm Lee?  Any footprints like the footprints of the discovery of the Higgs

 Footprints similar to the footprints of the Higgs particle found by experiment? Scientists built tremendous atom smashers to test theory, perform atomic experiments and seek answers. But as scientist Ben Santer has pointed out, we don’t have 2 earths to preform experiments with.


The Higgs theory was a model of elementary particles, how mass forms from nothing. (Don’t ask me about the Higgs field it’s way beyond me). But if we can’t experiment on a “control” earth.  But, we can model or simulate what will happen in the future. More and more the simulations are agreeing with the footprints and observations of global warming. 


The chemistry of the air and water is changing. Sure there are many natural “drivers” of our climate, but we are also now a driver.


The chemistry of the air, oceans, even land is changing.  We are now part of the experiment.  What will the "discovery" be 40 years from now?  As exciting as outcome of the experiment Dr. Higgs witnessed of his theoretical work?  Dr. Higgs never thought he would live to see the day an experiment, observations and footprints would verify his theory, his mathematical model.  What changes and experiments have we undertaken in the last 200 years with our environment and climate?  What will our grandchildren live to see verified?  A Higgs Boson . . .or something much bigger and maybe even more important?



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Air Conditioning Anniversary: 110 Years of Personal Comfort

July 17, 2012 - 04:35 PM

It's a stifling 100°, the humidity is unbearable, and all you want to do is stay in a cool and comfortable, air conditioned enviornment.  Wait a second, it's 1900 and there is no air conditioning!  Hard to imagine, right?

I know it is for me.  We're all so accustomed to "cool" spots in the summer.  Whether that's at the movie theater, museums, shopping malls, or even in our homes and cars.  So who is the genius who invented air conditioning?  The one responsible for our comfort on those blazing summer days?  This is him!

Dr. Willis H. Carrier - Inventor of Air Conditioning

Dr. Willis H. Carrier.  Last name sound familiar?  It's a well-known air conditioning company today.  Carrier was a young research engineer who graduated from Cornell University.  Shortly after college, Carrier designed a machine that would control the humidity in a New York printing plant in 1902.  This invention would go on to be a summertime haven for many people.  Take a look at Carrier's blueprint of this groundbreaking design. 

1902 Blueprint of Groundbreaking Invention

In the beginning, in the early 1900s, this new invention was used primarily for industrial purposes, but slowly became more mainstream over the years.  It was in 1930 that the Batlimore and Ohio Railfoad ordered Carrier air conditioning for its dining cars.  Here is what the first air-conditioning system likley looked like:

Early 1900 Air Conditioning

Oh how times have changed.  Take a look how some of the most recent air conditioning units look:

Modern Day Air Conditioning Unit

So a happy 110th anniversary to air conditioning - a milestone invention I will always celebrate in the summer!

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Types of clouds: Which kind is your favorite?

July 17, 2012 - 05:00 AM

I don't know about you, but one of my favorite things to do is look up into the sky to see the different types of clouds.  Sometimes the clouds produce snow, rain, or storms.  Other times they are few and far between.  My personal favorite are the ones that look like fun shapes!  So of all the clouds, which ones are your favorite?

Here's a quick overview of the different types of clouds.  Keep in mind, these are just the basics.  There are even more than just the ones described below, but this will get you started.

Clouds are classified based on their height and appearance from the ground.  There are low, middle, and high level clouds. 

Low Clouds: Stratus

Stratus Clouds

Stratus clouds are usually found below 6,500 ft.  Stratus clouds are generally uniform and flat and cover the entire sky.  They are the type of clouds you see on a gray day.

Mid Level Clouds:  "Alto" Clouds - Altostratus and Altocumulus

Altostratus Clouds
Altocumulus Clouds

"Alto" is used as the prefix to clouds that are found in the mid level of the atmosphere - generally 6,500 to 20,000 ft.  They can be associated with stratus or cumulus clouds (definition farther down). 

High Clouds:  Cirrus

Cirrus Clouds

Cirrus clouds are the highest clouds in the sky.  They are near 20,000 ft in the atmosphere and look thin and whispy.  These clouds are made up mainly of ice crystals because they are so high up in the sky.  The prefix "Cirro" can be added before stratus or cumulus if they fit multiple characteristics. 

Vertically Developed Clouds: Cumulus

Cumulus Clouds

Cumulus clouds are thick, puffy clouds that sometimes resemble cotton balls.  With the right imagination, they can take on many different shapes and figures.  Cumulus clouds can range from near the ground to above 50,000 ft.  You may hear forecasters refer to fair-weather cumulus clouds that are associated with dry weather, but these clouds can also lead to thunderstorms.

So where do the rain clouds come into play?  Well, if you add the prefix "nimbo" or suffix "nimbus" to one of these cloud types it then is referred to as a rain cloud.  For example, if a cumulus cloud produces a thunderstorm, the cloud would then be a cumulonimbus.  Remember those low lying stratus clouds?  If it starts to rain from them, it is now a nimbostratus cloud. 

Cumulonimbus Cloud

Wondering where the names of clouds came from?  We have Englishman Luke Howard (1773-1864) to thank for our cloud classification.  Before 1800, clouds were referred to as "essences" floating in the air.  Howard went on to published a book titled "On The Modification Of Clouds" around 1802 or 1803.  The names of the clouds are based off Latin terms.  Cumulus comes from the word "heap", stratus - from the Latin word "layers", and cirrus - meaning "curl" in Latin. 

Here's a great link from The National Weather service on cloud classification and characteristics

Take a look at this timelapse from a summer thunderstorm in Arlington, VA courtesy of our WeatherBug camera at Washington Lee High School.  Can you name some of the clouds seen in here?  Have fun with it!

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D.C. Drought And Heat: How Dry And Hot Locally And Nationally

July 13, 2012 - 05:00 AM

You've heard and read about the devastating Colorado wildfires, the crops that are suffering due to the lack of water, and the record breaking heat across much of the country.  All of these devastating events occur because of the heat and drought.  They are both interconnected.  The latest drought monitor was released Thursday, July 12, 2012 and once again, shows much of the country under severe to extreme drought conditions.

U.S. Drought Monitor July 10, 2012

Locally, the Nation's Capital falls under the abnormally dry and moderate criteria.  Parts of the Eastern Shore of Maryland are dealing with a severe drought.

Local Drought from July 10, 2012 Drought Monitor

Not only has it been very dry, but also very HOT!  The recent January to June 2012 period was the warmest for the Mid Atlantic and US in weather records. Take a look at the states that were the warmest on record across the U.S. Both Maryland and Virginia fall into the record warmest category for the 6 month period. 

NCDC State of the Climate

So is there a correlation between the heat and drought?  Well, yes there is.  The two can sometimes "feed" off each other.  Look at it this way:  If the ground and soil are abnormally dry, then the sun heats up the ground faster (there's no water in the ground that the sun needs to evaporate, which is a cooling effect), so the temperature continues to climb.  This process can sometimes continue for days, weeks, and months at a time and this relationship is known as a "positive feedback". 

The presence of a drought can enhance the heat and vice versa.  Another factor that can play into the excessive heat in the summertime, especially, is the Bermuda High.  A Bermuda High is a general area of high pressure that develops over the Atlantic in the summer and can bring the Eastern U.S. a persistent South to Southwest wind flow.  This then pumps up the hot and humid temperatures from the Southeastern states. The graphic below is a good visual of what happens with a Bermuda high offshore:

Courtesy USAToday

A good, soaking rain is very much needed in many of these drought stricken areas, but the weather front that pushed South into the Carolina's Sunday, July 8th, not only brought relief from the wicked heat, but also showers to some of these exceptionally dry areas.  The drought monitor is updated every Tuesday and released every Thursday.  We'll keep you posted on the updated maps. 

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