From the ABC 7 Weather team

Archive for March 2013

Easter Weekend in D.C.: A 'hoppy' forecast

March 30, 2013 - 05:00 AM

Easter weekend has come again.  Easter falls on the first Sunday after the first full moon after the vernal equinox.  Astronomical spring arrived on Wednesday, March 20th and the full moon occurred this past Wednesday, March 27th, ergo why Easter falls this weekend.

After a fairly cool, spring, temperature pattern this month, the pattern will change slightly for the holiday weekend. Along with the milder (more seasonable) temperatures, also comes the chance for showers. 

Sunshine will be the dominant weather feature on Saturday with highs in the upper 50s to lower 60s.  By Sunday morning, clouds will be on the increase and showers will develop ahead of a weak front.  Most of the rain should hold off until after lunch time in the metro area; however, showers may begin as early as 10am along the Blue Ridge.  Temperatures will be quite mild, though, near 60 degrees.  Check out our hyper-local futurecast that shows showers moving in late morning/early afternoon (early showers West of D.C.). 

The 135th annual White House Easter Egg Roll will take place on Monday and the weather looks pretty good for the event.  Another mild day expected Monday with highs in the mid 60s and breezy, too, ahead of a more potent cold front that will slide through late Monday night. 

Enjoy the 60 degree temperatures this Easter weekend and Monday because highs will drop back into the lower 50s with gusty winds come Tuesday and Wednesday of next week. 

Have a happy and safe Easter everyone!

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Palm Sunday Snowstorm: 71 Years Ago Today

March 29, 2013 - 05:00 AM

Earlier this week, D.C. received its first inch of snow in nearly two years!  No records were set in Washington, but a daily snowfall record of 3.2 inches was recorded at BWI and Dulles.  This March's snow was certainly not one for the record books, but March of 1942 certainly was.

Library of Congress

Not all of us remember, but it was a historic late March snowstorm that was named the 'Palm Sunday snowstorm' since it fell the weekend before Easter that year. 

Looking back at previous records and accounts, mainly from Sterling's National Weather Service, it was an unexpected snowstorm that crippled the region.  On March 29th rain began in the area, but changed over to a very heavy, wet snow and continued for many hours.  The snow stuck to power lines, trees, and shrubs, which weighed them down and caused massive problems.  Here's a surface map of the storm.  Notice the area of low pressure off the mid-Atlantic coast.

US Department of Commerce - Weather Bureau

The ironic thing was just twelve days earlier, high temperatures climbed into the upper 70s, so trees were already starting to blossom. 

The Palm Sunday snowstorm is the heaviest March snow on record in Maryland.  Baltimore and Hagerstown measured 22 inches of snow.  Hagerstown's 22 inches fell in a 24 hour period!  Washington received a total of 12 inches.  The record snow for March 29th is 11.5" from 1942.  That's the highest record snow in March, since weather records began. 

Library of Congress
Library of Congress

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Extreme weather: The new normal?

March 27, 2013 - 03:33 PM

Is the weather really going to extremes, or are we just more aware about “extreme weather” thanks to the news and blogs?  Well, March 2013 has sure been an extreme change from March 2012. 


March 2012 was the warmest one on record here in Washington and across the United States. But at the same time across the globe, March 2012 was the coolest since 1999. 


In fact, while March 2012 set more than 6,000 record highs across the U.S., March 2013 so far has seen only a bit over 500 with most in the west. The National Climatic Data Center (NCDC) plot of the climate extremes index (extremes of temperature and precipitation across the U.S.) shows extremes of weather increasing, or at least becoming more probable. 



Why is this happening? Are weather patterns changing? Many climate scientists think the answer is yes. Like any good detective, let’s look at the scientific - not political - footprints.

Earth is warming, the chemistry of Earth’s air and water/oceans is changing and we are sure a large part of the reason why. 

ZZZZZThe famous Keeling Curve shows not only about a 40 percent increase in carbon dioxide in the air over the last 150 years, but an increasing rate of change.
Changes in the global temperature are most dramatic in high latitudes in the Arctic.


 Courtesy Dr. Jennifer Francis-Rutgers University

This greatest warming in the Arctic, by the way, was predicted about 50 years ago, in some of the earliest simulations of a world with increasing concentrations of greenhouse gases.
So what if the Arctic warms? Not everyone in Greenland and marginal agricultural areas think longer growing seasons are terrible. But look at the changes in Arctic sea ice in this warming world.  

Courtesy Cryosphere Today
It shows dramatic decreases not only in summer, but in winter.  
A warmer arctic with less and thinner ice means more Arctic Ocean surface water. 
Of course, more water means more evaporation.

Courtesy Dr. Jennifer Francis
Some recent studies suggest a weakening in the mid-latitude jet stream
You can see that there's not as strong a temperature contrast from the equator to the poles.
Weaker westerly winds (also called Rossby waves in the general circulation) and a higher probability of blocking patterns or patterns with slower moving waves and persistent north to south, or south to north winds at high latitudes. 

 CourtesyDr. Jennifer Francis-Rutgers University

The result is a higher probability of extremes in the weather. That means  possibly longer droughts and heat waves, but also persistent cold waves or stormy patterns.

Depending on the persistence of these blocking patterns (Stu Ostro of The Weather Channel has a wonderful extensive presentation that he has developed over the years), some weather may be just unusual or a once-in-a-lifetime extreme event over days or weeks.

The long term outlook? More extremes. A simulation of a world with three times the carbon dioxide we’ve already added to the air shows dramatic decreases in the normal west-to-east jet and dramatic increases in the flow (meridional) from north to south and south to north.  


Courtesy Dr. Jennifer Francis Rutgers University

Does all this mean no more snow in Washington?  No, but maybe the super snowy winter 2009-2010 followed by our recent two almost snowless winters will become the new normal.

Summers may be hotter, contain more persistent droughts and longer heat waves, but they also could feature increasing probabilities of heavier rains storms.

Not every extreme weather event is due to us, but as many researchers have said, “We are stacking the deck."

Stay tuned. We’ll all find out over the next 20-50 years. More interesting resources and recent blogs on this and related topics can be found here:

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Washington, DC. sunrise and daylight info (timelapse)

March 27, 2013 - 08:31 AM

The sun rose at 7 am for the last time this spring in Washington, D.C. As our daylight increases the sunrise will continue to be earlier and earlier with the earliest sunrise at 5:42 am June 10th-17th. Mid June is also when we have the maximum amount of daylight (14hrs 53min). The next time the sunrises at 7 am isn't until September 26th. Enjoy the increasing daylight and this time lapse of the fantastic sunrise this morning.

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Late March Snow in D.C.: Any Records?

March 25, 2013 - 03:56 PM

Meteorological spring began March 1st and astronomical spring arrived March 20th at 7:02am.  Just when we thought, after a relatively snow-less winter, we were done with snow for the season, Mother Nature threw us a curve ball.  Just as forecast, snow started falling late last night and many people woke up to a winter wonderland.  We received some beautiful pictures from our news and weather team, as well as from loyal viewers. Check out the full photo gallery here.

Mary Kay Mallonee - Shirlington, VA

Snowfall totals were higher farther north and west of the metro area, but D.C. and southern Maryland still picked up some measurable snow.

Reagan National recorded 1.3" of snow, which is not a record for the day.  The record still remains 1.5" from 1906.  Even though it wasn't a record for the day, the inch of snow at DCA ends the longest inch-free streak in D.C. history!   The last time Reagan National received more than an inch of snow was back on January 26, 2011 -- Commutageddon

D.C.'s 1.3" of snow today, March 25th, will go in the record books, as the most late March snow in 23 years.  The last largest recorded snowfall at DCA was 1.9" on March 24th, 1990.  Dulles also falls in this category with 3.2" of snow today.  The last time Dulles received 3 inches of snow, this late in the season, was also on March 24th, 1990. 

A few snowfall records were made this late March date.  Both Dulles and BWI received 3.2" of snow, which breaks the previous records from the early 90s.  Reagan was close to at least tying a record, but was .2" short. 

An interesting tidbit I read on the NWS Sterling discussion, Dulles received 3 inches of snow on 3/24/90, another 1.2" on 3/25/90,  and then 2.7" on 4/6/90!  It's not common to have snow this late in the season, but from the stats here, it's definitely not a rarity. 

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D.C. area snow timeline, totals and photos

March 25, 2013 - 08:47 AM


Snow will taper off over the next few hours across the region as it gets closer to lunchtime on Monday. As of 8am, Reagan National Airport has recorded 1.3", which is the first inch of snow since January 26, 2011. That date just happened to be Commutageddon which I imagine many of you remember. Winter Weather Advisories continue through Noon for parts of the Metro north and west and Winter Storm Warnings continue through 6pm along the Blue Ridge and points west.

Photo Gallery Here

Fox in the snow from Brenda Vinson Johnson in Boyds, MD

Doppler radar continues to show the heavier bands of snow moving east with the majority of the snow now over the Eastern Shore and moving north into New Jersey. Snow will still continue to be possible through the late morning hours and even linger as snow showers or flurries at times through the afternoon. Now that the sun is up, no further accumulations are likely, as temperatures have started to climb into the mid 30s.

Snow in Hamilton, VA from Kelly Gaitten

Snowfall totals across the area were heavy in a few spots overnight. The highest snowfall was seen over the Blue Ridge and points west.

Harrisonburg, VA: 7.5"      Luray, VA: 6.7"

Oldtown, MD: 5.5"      Middletown, MD: 5"

Stephens City, VA: 5"      Bealeton, VA: 5"

Middleburg, VA: 4.5"      Frederick, MD: 4"

Snow will continue to come to an end through the afternoon hours. Here's a quick look at our timeline. A few pockets of moderate snow will linger through Noon but should taper off to flurries later today. We think a few flurries or showers will continue to be possible tomorrow as well with unseasonably cool temperatures hanging around through the end of the week.

Snow timeline

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Washington Snow: Another Close Call (Update)

March 24, 2013 - 02:15 PM


UPDATE (9:30PM - Alex Liggitt): So I'm sitting here watching Twister on ABC Family channel wondering where spring is. Light snow continues to fall across the D.C. area, which some have called white rain. Heard that from @capecodweather on twitter, pretty funny but true.


Snow in Charlottesville earlier Sunday from Melissa Paige

Surface temperatures in the D.C. area have continued to stay above freezing besides Winchester at the 9 o'clock hour which sits at 32. I've seen some reports of snow sticking to grass, decks and elevated things such as cars but not really to the roads yet which is good. This will change heading late tonight going into the morning hours, particularly in the far western suburbs along and west of the Blue Ridge. The first batch of precipitation is exiting the region, while the next batch will enter early tomorrow morning.

The Winter Weather Advisory has been expanded east to Montgomery and Howard Counties in MD now which is in effect from 4am to Noon Monday. The thought is there will be moderate to heavy snowfall at times in some localized areas tomorrow morning which will impact the morning commute. In any heavy bands, some slushy or slick spots may form on the area roadways, so be sure to get up early, check for closings and delays, and give yourself some extra time to get to work.

Some local models bring in this more moderate to heavy snow in the early morning hours just before sunrise which would be a terrible way to start the morning in D.C. given the commute. Snow will continue through lunchtime before tapering to scattered snow showers through the afternoon hours. Temperatures in D.C. should remain above freezing, so it will be tough for accumulations unless there is a heavier band that sets up overhead. Just west of D.C., there will be cooler air available, so accumulations will be possible, though they are expected to be light (1-3") and lead to those mentioned slushy slick spots. Higher totals (4"+) will be possible in the higher elevations of the mountains and Shenandoah Valley. Be sure to watch Steve Rudin tonight at 11pm and catch Adam Caskey early tomorrow morning at 4:30am on ABC 7 News.


UPDATE (4:30PM - Adam Caskey):  CHART road temperatures are generally in the upper 40s throughout the metro area, and most of Maryland (we don't have data for Virginia), so even once it begins snowing in the metro area, it'll melt on contact with the roads.  Heavy enough snow can overcome the warm roads and cool the road surfaces enough for snow to accumulate, but that will most likely be far west of the I- 95 corridor - similar to last Monday morning.  This is why most accumulations should be minor and mostly on grassy surfaces in the metro area.  That is, unless temperatures take an unexpected drop.  The farther west you are from I-95, the more likely your roads and side streets are of having a coating of snow by tonight and Monday morning. Road temperatures:


Road temperatures as of 4:30pm Sunday

Here's a snapshot of Live Super Doppler Radar, which can always be found here. Keep in mind that not everything you see on the radar right now is hitting the ground as the air is still saturating along the leading edge of the precipitation.

Live Super Doppler 7 radar at 4:45pm Sunday

I know.  Oh boy I've heard this talk of snow already too many times this winter and now it's spring so STOP IT!  But even though today the temperature is in the 50s and roads temperatures under the strong March sun are in the 60s, there is a risk (right now 50% chance) of enough slushy wet snow by Monday morning to be causing problems for the Monday morning commute for the western and northern suburbs.  The storm that is just forming  in the western Great Plains 


By Sunday will move to the east and very likely (70% chance) follow a path of previous storms this winter, that is move to near Ohio and then reform just off the North Carolina and Virginia Coast Sunday night and Monday.  The ground is warm and the lower air is warm with a strong March sun most of the precipitation in the metro area is likely (70% chance) to be rain.  But once again by late Sunday night and Monday, as the storm reforms, that rain-snow line is likely to be right along the I-95 corridor.  Here is a look at the rain-snow probability line from a high resolution simulation of the storm from SUNY Stony Brook 


As in previous storms high spots (500 feet and higher) are likely (70% chance) to see some heavy wet snow into the Monday morning commute.  The storm again poses a threat, depending on the exact track as the storm begins to reform, of bringing heavy snow to the northeast and New England.  The latest snowfall accumulation for our area from NWS. 







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D.C. snow forecast for Sunday and Monday

March 22, 2013 - 01:15 PM

Another late season winter storm is expected to develop in the lee of the Rockies tomorrow before moving across the U.S. into the D.C. area late Sunday into Monday. Snowfall looks likely from portions of Colorado, through the Central Plains, Mississippi Valley and Ohio Valley before finally making its way to the Mid Atlantic.

Winter Storm Watches and Warnings

What to Expect

This system is looking rather similar to snowquester in some respects, with a much higher likelihood for snow west of D.C. especially in the higher elevations. We're not expecting quite as much snow, as parts of the Blue Ridge and Alleghany Mountains saw over a foot of snow with that storm.

For the D.C. Metro, snowfall accumulations will again be on the low end. We may actually see the scenario where snow is falling but doesn't actually accumulate, as surface temperatures should remain above freezing for the majority of the event if not for its entirety. It will be something to look at around town, but high impacts do not appear likely at this point for the Metro and points east.


Precipitation is expected to move into the area late on Sunday, making it to D.C. by the late afternoon or evening hours. At this point evaporational cooling will lead to light snow at first, but it may become more moderate at times overnight into Monday morning. Snow will continue to be possible throughout the day on Monday as the low progresses off the east coast. Flurries may even linger into Tuesday.

Timing of the snow on our Microcast Model

Snowfall Potential

Well, let's see... It'll be March 24th and 25th, there is a much higher sun angle, surface temperatures should be above freezing, there is no real cold air in place until the system pushes east of D.C., there's a lot working against snow. Again, this will be a lot like last week.

Probability of 1" or more of snow for 24 hours from Sunday to Monday morning

With all of that out there, snowfall totals should be light around the immediate D.C. area, with our current thoughts around an inch or so in the grassy surfaces in the western suburbs. D.C. and points east should have enough rain mix in that there really won't be any accumulations. The mountains and higher elevations to the west may see a few inches, but again mainly on side roadways and the grass. Higher traveled roads should be better unless you are traveling as far west as I-68 where there may be complications.

As always, changes are likely as this storm hasn't quite developed out of the Rockies just yet. We will have better information this weekend and will continue to keep you updated over the next 48 hours.

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Spring Outlook: Any Warm-Up?

March 22, 2013 - 05:00 AM

March and the spring season have started off much cooler than average.  Not only for us here in D.C., but across much of the country. Check out the high temperatures across the U.S. yesterday and the departure from average. 

So is this cooler than average temperature trend going to last for a while? Well, it's bound to warm-up, at some point, it just make take a little time. And after going over NOAA's recent seasonal outlook, there is hope for warm weather lovers. The Climate Prediction Center is a part of NOAA and recently released their three month seasonal outlook.  The outlook predicts weather for April, May, and June.

When I mentioned there is hope for warm weather lovers, check out the three month seasonal temperature outlook for the U.S. 


About a third, to half, of the country has a great than 30% probability of experiencing above average temperatures.  It's a little hard to imagine, right now, when much of the U.S. is enduring a cold start to spring.  Now this doesn't mean there won't be cooler than average days, but overall, the trend will be for milder than average temperatures.

As for precipitation, the highest probability of wetter than average conditions exists over the Great Lakes and Midwest, where as a drier than average outlook is forecast for much of the west and along the Gulf. 


Much of the southwest remains very dry and under a drought.  The most recently updated drought outlook doesn't look very promising for those very dry areas in the southwest.  Also, notice areas NOAA has highlighted as a heightened flood risk this spring.


The overall outlook for D.C. looks fairly average in regard to precipitation with the potential for above average temperatures. 

For a more detailed explanation from NOAA, watch this great video.  

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Snow on the Eastern Shore today (Ocean City, MD Video)

March 21, 2013 - 04:07 PM

Check out the light snow that fell in on the Eastern Shore as seen from our WeatherBug camera at Plim Plaza in Ocean City, MD. Nothing like snow at the beach!

In addition, here's some video from Dewey Beach from on Facebook.

Related: A Tale of Two Marches

As far as snowfall totals,it was pretty pitiful, with 0.1" reported at Dulles Airport and Herndon in VA and Damascus in MD. As I watched our youtube video, I found another fun one that you may think is cool, from January snow at Virginia Beach. Check it out!

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A Tale of Two Marches

March 21, 2013 - 05:00 AM

It doesn’t take an advanced science degree to know that it has been a cold month! In fact when you look at the first three weeks of March we are averaging 51.7° which is well below the seasonable average of 57°! Even the National Cherry Blossoms are balking at the chill and have decided to delay their floret elongation by a week! (See the latest blossom information here.)

So why does it feel off to so many of us? Just one year ago we had an extremely warm March. In fact, the warmest on record and by this point last March we had already had SIX 70 degree days and THREE 80 degree days! Wow! So unlike this year we were running nearly 10 degrees above the seasonal norm and I am pretty sure us weather folks were not hearing too many complaints!

It’s not that we had a long or harsh winter, but honestly this spring (no matter how you characterize it: solar, astronomical or meteorological) has been a letdown.


We have had more snow opportunities late in the season and the temperatures feel like they are headed in the wrong direction.

Today for example, will feature temperatures near 40 degrees and wind chills in the 30s – yes 30s! The end of the week and start of the weekend will see a minor rise is temperatures, but still barely make it to 50 degrees. This pattern will continue well into next week, if not even longer. Plus, computer models are persistently simulating the development of an east coast storm on Monday…maybe a repeat of this past Monday.

In summation I would like to take a line from the late, great Bob Hope: Thanks for the Memories March 2012!

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Environmental Film Festival in its 21 year!

March 20, 2013 - 12:42 PM

Obviously, the DC area has many different attractions to offer visitors and residents. One of these events is the Environmental Film Festival that is in its 21st year. Although this film festival began March 12th, you can still have a chance to view some films, in the 75 different venues around town, before the festival wraps up this Sunday, March 24th. And to put the icing on the cake- most of these films are free! - (including the two featured below).





The festival, during its duration, has presented works featuring 190 documentary, narrative, animated, archival, experimental and children films all providing different and fresh perspectives on environmental issues not only here in the states, but globally with cinematic work from more than 45 different countries. The theme of this year’s festival is how rivers and watersheds play a vital role in the environment and the ecological importance and threats to these systems.

One of the interesting films on the docket for Thursday, March 21st is “The People the Rain Forgot.” This informational film gives viewers an inside look at how the drought and more irregular rain patterns have ravaged the livelihoods of millions of Africans whom rely on the rainfall for their well-being. Over the past four years, much of the region has not received sufficient rain to feed their livestock and to simply water their crops. The film depicts the courage and determination of those who are doing anything and everything to make the rain fall again. 




Another great film that runs on Sunday, March 24th follows the theme for this year’s festival. “A River Runs Through Us” explains how climate changes will affect the rivers and dams in attempt to motivate activists to protect rivers altogether. It also shows what can happen to communities affected by large dams and what can be done to preserve life-giving waterways while meeting the needs for energy and water.


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March going out like a COLD lion

March 20, 2013 - 06:27 AM
Photo: Smithsonian National Zoo

Time for true confessions of a Meteorologist. I know I am supposed to love all kinds of weather, and I know this has not been a harsh winter for us in D.C, but I’m over it.

Meteorological spring arrived March 1. The Vernal Equinox happened at 7:02 a.m. Wednesday, my daffodils are blooming, and I am completely ready for spring! I’m guessing you are too, based on the comments I have been receiving on Facebook and Twitter.

Now, I hate to be the bearer of bad news for you warm weather lovers (I am just the messenger here), but more winter-like temperatures are on the way. March will be going out as a cold lion.

So, what the heck is going on that we are talking about snow showers and well below average temperatures, you ask?

Well, we can blame something called the North Atlantic Oscillation (NAO). The NAO causes changes in weather patterns. When the NAO is in a negative phase, like it is now, it drives the polar jet stream to our south. So, what does that really mean for D.C.? Still with me?

Jet Stream from Intellicast


The polar jet stream is a fast current of air about 5-7 miles up in the atmosphere that divides the cooler air to the north and the warmer air to the south.

When there is a kink or trough in the jet stream, like there is over the Great Lakes and east this week, it allows cool air from Canada to freely descend upon us. In addition, storm systems generally travel from west to east within the jet stream.

So, with cool air in place and storms tracking to our south, it is a more likely set up for snow showers than rain showers in our region. This was the case for many of us last weekend.

And some light snow/flurries can be expected again Wednesday night. In contrast, when there is a bump or “ridge” in the jet stream, warm air builds up under the influence of high pressure. Those under the ridge tend to see calm, sunny and mild conditions. 

Trough and Ridge

These long wave patterns tend to stick around a while and it looks like that is the case for the rest of March. Here’s a look at the GFS computer model forecast for the jet stream next week, Wednesday, March 26th. 

Forecast Jet Stream March 26th

Notice the cool trough still over the Mid-Atlantic. At least one computer model is also trying to bring snow showers back at us early next week with this long wave pattern! Notice the bump out West. I’m heading for the Valley of the Sun next week to rejuvenate. Look out Spring Breakers!

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Spring Equinox: The View From Space

March 20, 2013 - 02:10 AM

OK this may be the quickest blog you've ever read.  Imagine you are about 20,000 miles in space at the altitude of the geostationary satellites.  Geostationary in that the satellites rotate around the earth above the equator at the same speed that the earth rotates.  Thus they remain (with some adjustments) in one spot above the earth's equator .  Here is the view from the GOES weather satellite late yesterday.  


See the equinox?  OK I've circled  it.  It is the glint (or reflection) of the sun in the afternoon.


In this afternoon GOES image, imagine you are flying in space with the sun behind you and the earth in front of you. The plane of the equator and the orbital plane of the earth's movement around the sun are all aligned and you see the reflection of the sun in the Pacific Ocean.  The reflection is right at the equator.  It's the equinox.  See it?  :>)

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D.C. National Cherry Blossom Festival Nearing (Update)

March 19, 2013 - 12:00 PM

Japan gave 3,020 cherry trees to the U.S. in 1912 as a symbol of friendship. Each year since, the blooms come alive during the warmer early spring and attract thousands of people to the nation’s capital. The splash of color that surrounds Washington as the trees bloom serves as the first spring celebration.

First Lady Michelle Obama was the honorary chair for last year’s celebration and planted one cherry tree in West Potomac Park. This year, 150 trees will be planted there to add to the spring scenery.

The National Cherry Blossom Festival kicks off on March 20 and goes through April 14. There are a variety of activities, ranging from arts and culture events to a 5K race, 10 mile race and even a half-mile kids’ run.


(Photo courtesy of


Green buds appeared on March 11 and The National Park Service originally said the peak bloom (when 70% of the cherry blossoms are open) would be from March 26-30. That is about a week earlier than average with the peak bloom date is usually April 4. Since March has been such a cool month (uhh, it was 40 degrees yesterday for a high) the peak bloom has been pushed back. The National Park Service is now predicting for a peak bloom between April 3 and April 6, which lies right around average.

Looking back through time, the cherry blossoms have mostly peaked ahead of schedule (or average) for the last decade. Here’s a closer look year-by-year when the cherry blossoms have reached the greatest color, including the earliest and latest peak blooms.


The blooming period, defined as the time span between when 20% of the blooms open until the petals fall, typically lasts 10 days to two weeks.

Last year, the cherry blossoms peaked earlier than this year’s expected peak bloom due to the very warm weather. The string of 80-degree days in early March accelerated the process.

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D.C. area snowfall totals and pictures

March 18, 2013 - 12:20 PM

Winter just seems like it doesn't want to end. It's hard to say this as I feel like it never really started with such pitiful snow amounts this year. Once again, measureable snow was limited to the western suburbs of D.C. The farther west the better, with multiple inches reported in the mountains of West Virginia, to a couple of inches reported along the Blue Ridge.

As far as snowfall totals are concerned across the region, here are some of the totals that were reported to the NWS Sterling office.

Madison, VA:  3.8"

Culpeper, VA:  3.3"

Frostburg, MD:  2.8"

Winchester, VA:  2.0"

Fredericksburg, VA:  1.5"

Leonardtown, MD:  1.1"

Snow reports into the NWS Sterling today

Snow was lighter than the forecast models predicted last night, which was expected with the ample amount of dry air in the region as well as the warm ground temperaturers. Closer to the D.C. Metro, most snow melted on contact with the surface but did allow for a light coating on vehicles.

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D.C. Snow: Do I believe it this time?

March 18, 2013 - 12:15 PM

OK I admit it.  We've busted a number of forecasts this winter and the darn rain/snow line has been over D.C. almost every time.  It happened again overnight and early this morning.  Check out the pretty snow pictures here, and look at the "total" snowfall.  Again a trace in DC and our winter total remains a paltry 1.7"



Still some advisories out .  Last night I said AM rush will be slippery with 1-3" of snow west and north of DC by 6-8AM in the metro area before a change to rain (sorry again snow lovers) by noon.  Check out some of the pretty snow pictures . . .again mainly just west of DC.  So Bob's Odds for Monday's "Storm" not perfect but OK?:


Morning Rush Hour Snow NW Slippery Roads     50% Chance

Snow Changes to Rain around noon                      70% Chance

"Storm" all rain as "SnowQuester"                      only 20% Chance

A "Major" snowstorm (sorry snow lovers)          Near 0%


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Snow likely in the D.C. area tonight through Monday morning

March 17, 2013 - 06:02 PM

Snow already started falling across parts of the D.C. area today with up to 1/2 inch in Culpeper and Rixeyville in Virginia and more on the way. Our region lies along a frontal boundary that extends west into the Tennessee Valley. High pressure over the northeast is ensuring a supply of cool, dry air to the region which will help create the chance for snow tomorrow morning.

Above is a look at the 12Z GFS Model depicting the high located over eastern Canada and the northeast and a frontal boundary extending over the D.C. area. High pressure is pushing the cool, dry air into our region, which means surface temperatures should be cold enough for snow tomorrow morning. As the low moves closer to the region later in the morning, enough warm air will get into the area above the surface to change the precipitation to rain.

Here is a look at the 4km NAM model, which hasn't been the most trustworthy as of late, but still has the same depiction of most of the other deterministic models with snow in the region tomorrow morning during the morning commute.

Snowfall totals expected by our Hyperlocal Microcast

As far as snowfall totals, this will again be a storm that will rely on elevation, with snow already falling in the Blue Ridge and Mountains to the west. Higher snowfall totals will be experienced in higher elevations, with much lesser amounts closer to the D.C. area. Another issue with the D.C. Metro area will be the fact that snow will mainly just be found in the grassy surfaces, and will also more than likely be found on your car tomorrow morning so be sure to get up a couple minutes early to brush it off!

Timing has been showing snow coming into the region early tomorrow morning prior to sunrise and continuing as snow through the morning commute. Above is a look at our in-house RPM model depicting some moderate snow going on at 7am. This will surely have an effect on the morning commuters, so don't be surprised by it when you get up to go to work tomorrow morning. Winter Weather Advisories are posted in the immediate western suburbs with a Winter Storm Warning posted for northern Fauquier County and points west into the Blue Ridge and Shenandoah Valley.

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Feeling Like Ireland This St. Patrick's Day: What A Difference A Year Makes!

March 15, 2013 - 11:00 PM

Top 'o the mornin' to ya, this St. Patrick's Day weekend! D.C. certainly has the feel of Ireland today with clouds, cool temperatures, and a chance for showers in the forecast. OK, maybe it doesn't quite resemble the country without the lush green pastures and rolling hills, but oh well.

Jason Kottke - Kerry, Ireland

Regardless, the entire weekend will feature cooler than average temperatures and chances for showers, mainly today. I think most areas will be dry tomorrow for the actual St. Patrick's day holiday, but it will be cloudy and rather cool with highs in the 40s.

What a difference a year makes, though! Looking back to last March, temperatures were WAY above average. In fact, the high climbed to 82 degrees last March 15th, which set a new record in Washington.   I did a graphical comparison of the two months.  It's interactive, so roll your cursor over the lines to find out the actual highs.

The rest of March 2012 was well above average. In total, there were 14 days with highs at 70° or higher.  Last March was incredibly mild , overall, ending 10° above the monthly average!  So far, this month is just about average.  It's halfway through the month and no sign of any 70° temperatures.  The first day of March, last year, made it to 70°.

Wondering about last year's St. Patrick's Day weather?  The high made it to 75°!  This year, only about 46°.  The average high, for the middle of March, is 56°.  Maybe add a jacket if you're planning on going to the St. Patrick's Day Parade in D.C., but you can probably leave the umbrella at home with just cloudy skies.  Cheers!

Have a happy and safe St. Patrick's Day!

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Rain and the chance for snow back in the D.C. area one last time?

March 14, 2013 - 02:13 PM

Yes you ready the headline correctly, please don't throw your shoe at me. Who throws a shoe, honestly? After a brief lull in the wet weather, it appears the pattern will change once more, bringing back the chance for precipitation to the D.C. area from Saturday through next Tuesday. If that's not enough to make you mad at me, parts of the region will be cold enough for some snow to mix in. Happy mid-March everyone.

GFS 500mb Voriticity Forecast for Friday Afternoon

Above is a look at the 500mb vorticity plot for Friday early afternoon. I have circled the region of unsettled weather over the Northern Plains. This unsettled weather will travel along those constant lines of height (black lines aka isohyse) and right into the D.C. area through the weekend. Unfortunately, there is another larger area of storminess in the Pacific that will continue to bring this chance for rain to the region through early next week.

5-day Precipitation Outlook from HPC

Take a look at the rainfall potential for the next 5 days. Up to an inch of rain is forecast for the D.C. area with the potential for isolated higher amounts. The best chances for rain will be here Saturday morning, Monday and again Tuesday morning. A cold front will finally move into the region Tuesday afternoon bringing dry air back to the region.

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