"It sounded like a train and lasted about ten seconds but felt like five minutes."  Those are the words of a homeowner I spoke with whose home was significantly damaged by a potential tornado yesterday evening (5/08/08) in Stafford, VA.  She prefers to remain unidentified, but she had quite the story to tell. 

I took Storm Chaser 7 to the scene early this morning during Good Morning Washington to report live, witness the damage first hand and speak with homeowners.  To give you an idea of the worst damage, imagine a single family home made of vinyl siding and and some brick.  Now, imagine the roof and exterior walls of the second floor completely removed from the house and thrown around the neighborhood like a child tossing Legos.  All that's left of the entire upper level is tattered interior walls, furniture, plumbing, and personal belongings. 

That is a rough description of what two homes looked like in the England Run subdivision in Stafford, VA after a potential tornado ripped through the neighborhood.  This area was hardest hit where roofs were lifted, walls were blown out, cars were on lawns, patio furniture was mangled, windows were shattered, and mailboxes were thrown around and nearly flattened.  In one of the most severely damaged homes I found part of an interior wall of a kids room (on the upper level) that was thrown across the street (opposite storm movement) and onto a driveway two houses down.  Vinyl siding, shingles, lumber, mailboxes, potted plants, and other objects became flying projectiles.  Lumber from the roof of one house looks to have been lifted and thrown across the street (opposite of storm movement) and impaled through the siding of a neighbor's house.  I found a 2 x 4 sticking out of the wall of a babies room on the second floor of a home with other wooden boards and 2 x 4s strewn about the roof and yard.   We received preliminary reports of minor injuries but no fatalities...luckily.

This particular storm first developed around Charlottesville, VA at approximately 9pm and moved northeast through Spotsylvania County then into Stafford around 10:30pm.  The local National Weather Service office issued a severe thunderstorm warning around 9:40pm, and Shortly afterwards, a tornado warning was issued for several counties.  Fortunately, many people heard the warning, which is largely due to the woman mentioned above having a NOAA Weather Radio.  As a matter of fact, her family has several weather radios and first heard of the potential danger through the device.  Once the warning was issued, she called her neighbors to alert them, and she immediately took her family into their basement.  Other neighbors, whom I spoke with, received warnings through local media.

One reason I mention this story is to illustrate the importance of owning a NOAA Weather Radio.  We don't have a network of tornado sirens in the Midatlantic, so the best ways to obtain severe weather warnings are through local media and especially weather radios.  If a severe thunderstorm or tornado strikes at night while you're sleeping, the only way to hear of the pending danger is through a NOAA Weather Radio, which will automatically alert and sound an alarm even if turned off. 

IMPORTANT NOTE: The National Weather Service is surveying the damage today (5/09) and will determine if in fact there was a tornado, and if so, how strong it was on the Enhanced "F" Scale.  If you ask me, judging by the damage, storm movement, and orientation of damage, it was a tornado (maybe EF2), but I'm not as skilled and trained in surveying damage as the folks at the NWS.  Their preliminary report should be out later today or tomorrow.

So this afternoon I happened to be sitting in the ABC 7 Weather Center making a few graphics for the 6pm show when I heard a deep rumbling and minor rumble in the building.  I turn to my colleague Chris Naille who is the radio meteorologist here and say, "Geez, sounds like a plane just got pretty close to our building...", as our building lies in the flight path of Reagan National Airport.  The only thing is, I heard the same sound another 4 seconds later, so then thought it may have been an explosion or something.  Either way, we thought nothing of it as the sound went away and we went back to work.

About an hour later, after I go downstairs for a cut-in on News Channel 8 and come back upstairs, Chris starts telling me that there were lots of reports of something that sounded like an explosion on WTOP radio.  We go ahead and check the U.S. Geological Survey website and what do you know, we had an earthquake!  Here is a link to the page where the information was located:

http://earthquake.usgs.gov/eqcenter/recenteqsus/Quakes/ld1022071.php#details

It was a relatively weak earthquake with a magnitude of 1.8 on the Richter Scale and was located right by a bunch of my old friends houses as it was in the W.T. Woodson High School area near NOVA Community College on Little River Turnpike.  Many people across the region all the way into DC felt it as the shaking travels very well in the solid bedrock that is located beneath the surface here on the east coast.  This is like comparing the ground to a solid cement slab, where as western quakes don't travel quite as far due to the ground there, which is more like a brick patio with energy dissipating closer to the epicenter.

The largest earthquake in Virginia happened to be in 1897 when a 5.8 hit in Giles County which is along a seismic zone west of Blacksburg, VA.  The last weak quake to hit around the DC area was a 2.1 in Baltimore in 2005, and a 2.5 in Manassas, VA in 1997.  One other memorable one was a 4.5 located west of Richmond in 2003.

Doug and I were researching earthquakes in Virginia before the show and he came across a good article that talked about the 2003 earthquake and history of certain fault lines in Virginia.  You should be sure to check it out.

http://www.wm.edu/geology/virginia/whats_new/QuakeStory.pdf

  

www.extremeinstability.com

I randomly came across this site while surfing the web looking for pictures of supercells and tornadoes as I love weather photography.  This guy updates this site often and I have even bought a print from him of a supercell which is a 16" x 20" and looks really nice.

He also writes about all of his chases and includes pictures in those which are really interesting.  Believe me I don't know the guy but he does some good work and has incredible shots and links on his site.  I just figured since we are in the middle of severe weather season I would throw out a good site you should check out.

So apparently my birthday happens to lie on the date of some very violent weather history, with not only the tornadoes from yesterday, but also the La Plata tornado back in 2002.  Two of the tornadoes from April 28 in Colonial Heights and Halifax were measured with a peak intensity of EF-1 (EF standing for the Enhanced Fujita Scale which was implemented last year), and the other larger more intense tornado that went through the city of Suffolk, Virginia with a rating of EF-3.

 

EF-1 tornadoes have wind speeds in the 86-110 mph range, where EF-3 tornadoes have wind speeds in the 136-165 mph range.  Looking at doppler estimated wind speeds on our Live Supper Doppler radar, entering the storm we could see a wind shear velocity of 127 mph right after it exited the City of Suffolk, so there were very high wind speeds and a noticeable "notch" or hook echo when looking at reflectivities.  That tornado was on the ground for 15 minutes and spanned 10 miles in that time period with a top width of a quarter mile.  It was amazing that no one was killed by that tornado, but that was most likely due to the fact that there was a tornado warning in place for almost an hour, with the warning being issued at 3:11pm for portions of Suffolk, VA, and the tornado didn't actually come through the downtown area until 4:05pm.  The tornado warning was reissued at 3:50pm and stated that a tornado would be near downtown Suffolk at 4:05pm, and at 4:04pm, the tornado went through the northern part of the city.  The other  two tornadoes were only on the ground for approximately 1 mile, with the top widths from 80 to 240 yards wide.

 Here are a few pictures:

It is crazy to notice how selective tornado winds can be, with one house being completely destroyed, and the row of houses across the street remaining completely intact with minor damage.

Finally, here is a good reason you should heed these warnings and get into an interior room in the house such as a bathroom and a basement.  Notice that every single window has been blown out as debris from surrounding buildings, houses, trees, cars and anything else that could be picked up was thrown at the house.  This is absolutely horrible sight that I hope I will never have to see.  Our thoughts here in the ABC 7 Weather Center are with the victims from those storms.

 

 

With the recent rainfall of last week, our meteorologists, and I know you citizens, have been hoping that we made a major crack into the rainfall deficit that we've had through the beginning of the year.  Deficits through the beginning of April had already reached 2 and a half to 3 inches through the region.  Add to that the 6 inch deficit at Reagan National and BWI and the 13 inch deficit at Dulles from 2007 and that would make for a huge problem for the remainder of the Spring and continue through the more climatologically dry Summer months.

 

 So this last rainfall of 2 to 4 inches throughout the region late last weekend through earlier this week really has helped return our region toward normal.  As of April 24, Reagan National Airport is 0.45 inches of rain ahead for the year, Dulles Airport is down only 0.07 inches, and BWI continues to lag a bit behind with a deficit of 1.80 inches.  Overall, we can deal with this.  This isn't too bad, as we are still in the time of the year where we receive the majority of our rainfall.  Here is a look at the current Drought Monitor for Virginia:

Notice how even the abnormally dry region has backed farther to the south, and how the moderate and severe drought have also really taken a hit with the latest rainfall.  Here is the Maryland Drought Monitor for the week:

The only portions of Maryland still in the moderate drought are far Southern Maryland in southern St. Mary's and southern Calvert counties, as well as much of the Delmarva Peninsula.

Our next chance for rain will be during the evening and overnight hours tomorrow, a better chance Saturday with the passage of a cold front, and finally another chance Monday as a new area of low pressure crosses the region.  This could further help dig our region out of trouble for the approaching Summer months, as some models hint at rainfall amounts up to 2.5 inches of rain by Monday night.  The NAM model hints at less than the GFS, but either way, expect the region to receive something, and no matter how much it is, it will continue to help. 

Every Spring and Fall, the National Weather Service office in Sterling, VA hosts members of the media to come and take a look at their operations and meet with them to talk about different aspects of the weather.  Topics addressed this Spring were such as this years winter, or lack there of, severe weather in the region and past events such as the La Plata tornado and the Fall outbreak of tornadoes associated with the remnants of Hurricane Ivan, storm based warnings, and even the EF Scale. 

It is always great to get out there and form a good relationship with the meteorologists at the Weather Service as well as talk to meteorologists from other markets such as Baltimore and Charlottesville.  It was interesting learning how the EF Scale, or Enhanced Fujita Scale, is different from the old Fujita Scale in terms of damage based wind estimates.  A whole list can be found here:  http://www.spc.noaa.gov/efscale/ef-scale.html  You can click on each of the numbers to the left and it will show you different examples of damage made by certain estimated wind speeds.

Another important topic was the storm based warnings.  You know how when a warning used to go out such as a Severe Thunderstorm Warning or a Tornado Warning, the whole county was warned?  Now, just the particular area involved will be warned (i.e. Southeastern Fairfax County, moving east at 30 mph).  This is because there are so many people getting warned in some parts of the county that are not being affected that the NWS decided to make a change.  Here is a good website that shows examples:  http://www.weather.gov/sbwarnings/

Afterward, we took a picture there in front of their building and hit the road.  They are actually moving into a new building this Fall as Dulles Airport decided to put a runway where their current building is.  You can see Adam Caskey and I on either side of Chris Strong, the Warning Coordination Meteorologist.  Jim Lee, the Meteorologist in Charge, or MIC, is on the opposite side of me (white shirt), with Ron Riley of NewsChannel8 next to him, and at the end of the row, Steve Zubrick, the Science and Operations Officer there at the Sterling office.

A beautiful week is finally coming to an end and now we are looking to the weekend to continue this nice trend.  The weekend, however, doesn't exactly want to agree with us as a change is in the winds as a cold front begins to approach the region from the west.  Saturday is expected to be our last nice day with highs near the 80 degrees under partly cloudy skies.  I expect mostly sunny skies in the morning hours with increasing clouds by the afternoon and cloudy skies by evening and Saturday night.  This frontal system is expected to bring with it showers and maybe even a few rumbles of thunder during the day on Sunday. 

With high pressure developing to the northeast and low pressure moving overhead, an easterly flow at the surface is expected to set up and cold air damming against the mountains will cool highs into the low to mid 60s Sunday.  Model ouput is spitting out a moderate amount of precipitation Sunday and into Monday as this situation holds together.  Monday will be yet another cool day with highs only in the lower 60s.  The main problem with cold air damming situations is the models grasp on the longevity of the occurance.  They usually don't hold on long enough to the damming and break it down early, meaning model predicted temperatures are way too high and skies conditions are too sunny.  Regardless, we intend to break down this damming by Tuesday night into Wednesday as high pressure moves further to the northeast and has less of an effect on our region.  Highs Tuesday are still only expected to reach the lower 60s.  Enjoy this nice warm and dry weather while it lasts!

 

Clear skies, warm temperatures, light winds...  What else could we ask for at this time of year when the leaves are starting to come out, the days are beginning to get longer, and the new grass in my back yard is beginning to grow.  Highs today reached the 70 degree mark and are expected to again tomorrow, Friday and through the weekend.  I think we should expect one last cool night in the suburbs as lows may fall enough for some patchy frost, but around town, lows will only fall into the low to mid 40s.

Sunny skies will hold through the remainder of the work week, with partly cloudy skies taking over during the day on Saturday.  A disturbance is expected to cruise through the plains and into the Ohio Valley where a cut-off low then veers to the northwest of our region.  Warm temperatures will therefore hang around as winds should remain out of the west, but a few and I stress FEW added clouds will join us for the day on Saturday.  Saturday night and Sunday will be a bit different with added cloud cover and a slight chance for a few showers.

The only problem with such beautiful weather is the fact that we are already below average for the year in rainfall, and I was hoping the region would at least get a good base before the summer months.  As of now, it appears decent rainfall is expected to hold off until the end of next week, so we will not be out of the woods with this rainfall deficit for some time.  I'll give you more details tomorrow... 

There are many reasons to look forward to springtime in the DC area, but what I appreciate the most is the lack of humidity and haze.  As we all know, the heat and humidity make summertime weather oppressively sweaty and uncomfortable, and as early as late May, the humidity can rear it's ugly head.  This is why it's important to make the most of the mild Spring days before the humidity makes its annual surge northward from the Gulf of Mexico, and our air conditioning bills sky rocket, or course. 

 

High temperatures this week will slowly climb to near 80 degrees by Friday, and dewpoints will only rise into the upper 40s with our springtime, southerly flow.  For those not familiar, the dewpoint is the temperature the air must be cooled to in order to become saturated (100% relative humidity).  It is all you need to look at to determine how much moisture is in the air, and to figure out how comfortable or uncomfortable the day will be.  Normally, once the dewpoint is in the 50s, you begin to feel a touch of humidity, but it's not uncomfortable.  Dewpoints in the upper 60s and especially lower 70s are uncomfortable, and to some, unbearable.  In the summertime our dewpoint is most often in the 60s and lower 70s, so there is more moisture in the air causing it to feel hotter outside.  Also, without the added moisture in our air this time of year, we have baby blue skies rather than the hazy, blueish-white skies common in the summertime.

I understand comfort is all relative as I'd rather be too cold than too hot while others would like it the other way around, so it all comes down to personal preference.  Regardless, enjoy the lack of humidity & bright, blue skies and look forward to another month or so of conditions we will yearn for during the sultry summer, which is inevitably just around the corner.