September 8, 2012 Severe Weather

Radar Data from the Sterling, VA WSR-88D Radar (KLWX)

Click on each image (gif) to enlarge.

KLWX 0.5 Radar Reflectivity Animation
(12:01 PM - 5:01 PM EDT)

KLWX 0.5 Radar Velocity Animation
(12:01 PM - 5:01 PM EDT)

The image above is an animation from around 12 to 5 PM EDT (1601-2101 UTC) on September 8, 2012 of a line of thunderstorms that produced damaging winds as it moved through the region. Notice the leading line of thunderstorms that initially developed over extreme northwestern Virginia, the eastern panhandle of West Virginia and western/central Maryland between ~12 and 2 PM EDT. This initial line of storms produced damage mainly in Washington and Frederick counties, Maryland during the early afternoon. The line then developed farther south over the central and northern Shenandoah Valley between ~2 and 3 PM EDT, before organizing and strengthening as it crossed the Blue Ridge Mountains. The line of thunderstorms produced the most damage across the greater Washington D.C. metro in northern Virginia and central Maryland between ~3:00 and 4:30 PM EDT.

Although damage to date has been attributed to straight-line winds, several embedded (counterclockwise-rotating) circulations developed within the line (not shown). Consequentially, six tornado warnings were issued that afternoon. There were several reports of funnel clouds in northern Virginia and central Maryland, but none of the damage to date has been assessed as tornadic. This may change at a later date once additional storm surveys are conducted by the Baltimore/Washington NWS Weather Forecast Office.

In the radar images above, the small circular hole in the center of each image is the KLWX radar location in Sterling, VA; reflectivity values (left image) are in units of dBZ; velocity values (right) are in units of knots, with the green and cyan colors representing strong inbound velocities; bright red to orange colors representing strong outbound velocities.

Severe Weather Warnings and Reports from September 8th

The image above shows all Severe Thunderstorm, Tornado, Marine and Flash Flood Warnings issued by the Baltimore/Washington NWS Weather Forecast Office and Severe Weather Reports received during the afternoon of September 8, 2012.

NWUS51 KLWX 121738
LSRLWX

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
137 PM EDT WED SEP 12 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1229 PM     TSTM WND DMG     1 ENE MARTINSBURG       39.46N  77.96W
09/08/2012                   BERKELEY           WV   EMERGENCY MNGR  

            LARGE TREE DOWN IN 600 BLK OF QUEEN ST 

1245 PM     TSTM WND DMG     1 ESE HALFWAY           39.61N  77.75W
09/08/2012                   WASHINGTON         MD   DEPT OF HIGHWAYS

            TREE DOWN ACROSS MD RT 632 BETWEEN HALFWAY AND I-70 

1246 PM     TSTM WND DMG     1 ESE FUNKSTOWN         39.60N  77.68W
09/08/2012                   WASHINGTON         MD   BROADCAST MEDIA 

            TREES DOWN ON ROUTE 40 NEAR INTERSTATE 70. 

1250 PM     TSTM WND DMG     1 W CHEWSVILLE          39.64N  77.65W
09/08/2012                   WASHINGTON         MD   BROADCAST MEDIA 

            TREES DOWN ON ROUTE 64 IN ROBINWOOD 

1251 PM     TSTM WND DMG     BRIDGEPORT              39.64N  77.67W
09/08/2012                   WASHINGTON         MD   DEPT OF HIGHWAYS

            TREE DOWN NEAR MD 64 AND GREENDALE DRIVE 

1253 PM     TSTM WND GST     SMITHSBURG              39.66N  77.58W
09/08/2012  M58 MPH          WASHINGTON         MD   MESONET         

1255 PM     TSTM WND DMG     CAVETOWN                39.64N  77.59W
09/08/2012                   WASHINGTON         MD   DEPT OF HIGHWAYS

            TREE DOWN ACROSS MD RT 66 AT CAVETOWN CHURCH RD 

0113 PM     TSTM WND DMG     BURKITTSVILLE           39.39N  77.63W
09/08/2012                   FREDERICK          MD   911 CALL CENTER 

            TREE DOWN ALONG GAPLAND ROAD 

0113 PM     TSTM WND DMG     2 N ROCKY RIDGE         39.63N  77.32W
09/08/2012                   FREDERICK          MD   DEPT OF HIGHWAYS

            TREE DOWN NEAR MD RT 76 AND BOLLINGER RD 

0130 PM     TSTM WND DMG     4 SSW SABILLASVILLE     39.65N  77.48W
09/08/2012                   FREDERICK          MD   911 CALL CENTER 

            TREE DOWN ALONG PARK CENTRAL ROAD 

0239 PM     TSTM WND DMG     1 SE UPPERCO            39.55N  76.81W
09/08/2012                   BALTIMORE          MD   911 CALL CENTER 

            TREE DOWN AT DARK HALLOW RD AND DOVER RD 

0245 PM     TSTM WND DMG     2 WNW BUCKTON           38.97N  78.29W
09/08/2012                   WARREN             VA   PUBLIC          

            SEVERAL TREES DOWN ALONG RT 55. 

0256 PM     TSTM WND DMG     5 W PURCELLVILLE        39.14N  77.80W
09/08/2012                   LOUDOUN            VA   NWS EMPLOYEE    

            THREE TREES DOWN ON ROUTE 7. 

0258 PM     TSTM WND DMG     PURCELLVILLE            39.14N  77.71W
09/08/2012                   LOUDOUN            VA   NWS EMPLOYEE    

            ONE FOOT DIAMETER TREE DOWN ON HATCHER AVE 

0258 PM     TSTM WND DMG     1 WNW SCOTTSVILLE       37.81N  78.52W
09/08/2012                   ALBEMARLE          VA   911 CALL CENTER 

            A TREE WAS BLOWN DOWN NEAR THE 500 BLOCK OF IRISH ROAD. 

0305 PM     TSTM WND DMG     2 SE MIDDLEBURG         38.95N  77.72W
09/08/2012                   FAUQUIER           VA   911 CALL CENTER 

            TREE DOWN ALONG LANDMARK SCHOOL ROAD 

0312 PM     TSTM WND DMG     2 NE TURNBULL           38.69N  77.83W
09/08/2012                   FAUQUIER           VA   911 CALL CENTER 

            TREE DOWN ALONG SPRING ROAD 

0320 PM     TSTM WND GST     3 NW DULLES INTERNATION 38.98N  77.49W
09/08/2012  E63 MPH          LOUDOUN            VA   NWS OFFICE      

0320 PM     TSTM WND GST     ASHBURN                 39.04N  77.48W
09/08/2012  E69 MPH          LOUDOUN            VA   NWS EMPLOYEE    

0320 PM     TSTM WND GST     3 SW ASHBURN            39.02N  77.52W
09/08/2012  M58 MPH          LOUDOUN            VA   MESONET         

0320 PM     TSTM WND DMG     1 WSW AUBURN            38.70N  77.72W
09/08/2012                   FAUQUIER           VA   911 CALL CENTER 

0322 PM     TSTM WND DMG     3 SSW ARCOLA            38.92N  77.56W
09/08/2012                   LOUDOUN            VA   NWS EMPLOYEE    

            3-4 TREES SNAPPED IN COMMUNITY OF KIRKPATRICK FARMS 

0328 PM     TSTM WND DMG     1 SSW HAYMARKET         38.80N  77.64W
09/08/2012                   PRINCE WILLIAM     VA   911 CALL CENTER 

            TREE DOWN ALONG OLD CAROLINA ROAD 

0328 PM     TSTM WND DMG     5 ENE NORTH GARDEN      37.96N  78.56W
09/08/2012                   ALBEMARLE          VA   911 CALL CENTER 

            A TREE WAS BLOWN DOWN NEAR THE 1700 BLOCK OF LYNCHBURG 
            ROAD. 

0330 PM     TSTM WND DMG     1 NNW HERNDON           38.98N  77.39W
09/08/2012                   FAIRFAX            VA   NWS EMPLOYEE    

            MULTIPLE TREES DOWN. 

0330 PM     TSTM WND DMG     1 SSE NOKESVILLE        38.68N  77.57W
09/08/2012                   PRINCE WILLIAM     VA   911 CALL CENTER 

            TREE DOWN AT CARRIAGE FORD ROAD AND ALDEN ROAD. 

0332 PM     TSTM WND DMG     1 WSW MANASSAS PARK     38.78N  77.48W
09/08/2012                   PRINCE WILLIAM     VA   911 CALL CENTER 

            DOWNED TREES BLOCKING PORTIONS OF CHATHAM STREET AT 
            CLAIRMONT STREET. 

0333 PM     TSTM WND DMG     2 NW SUDLEY             38.82N  77.53W
09/08/2012                   PRINCE WILLIAM     VA   911 CALL CENTER 

            TREE DOWN AT LEE HIGHWAY AND SUDLEY ROAD 

0335 PM     FUNNEL CLOUD     S CHANTILLY             38.88N  77.41W
09/08/2012                   FAIRFAX            VA   FIRE DEPT/RESCUE

            FIRE DEPT REPORTS THE SIGHTING OF A FUNNEL CLOUD 

0335 PM     TSTM WND GST     CHANTILLY               38.88N  77.41W
09/08/2012  M58 MPH          FAIRFAX            VA   MESONET         

0335 PM     TSTM WND DMG     1 WNW FAIRFAX           38.86N  77.31W
09/08/2012                   CITY OF FAIRFAX    VA   PUBLIC          

            TREE DOWN NEAR US RT 50 AND RT 123 

0335 PM     TSTM WND DMG     4 SSE MANASSAS          38.70N  77.44W
09/08/2012                   PRINCE WILLIAM     VA   911 CALL CENTER 

            LARGE TREES DOWN BLOCKING ALL LANES ON DUMFRIES ROAD AT 
            LONGTREE DRIVE. 

0338 PM     TSTM WND DMG     2 WSW CARRSBROOK        38.09N  78.49W
09/08/2012                   ALBEMARLE          VA   911 CALL CENTER 

            A TREE WAS BLOWN DOWN NEAR THE 1700 BLOCK OF 
            EARLYSVILLE ROAD. 

0345 PM     TSTM WND GST     GAITHERSBURG            39.14N  77.22W
09/08/2012  M60 MPH          MONTGOMERY         MD   MESONET         

0345 PM     TSTM WND DMG     1 WSW CHEVY CHASE VIEW  39.02N  77.10W
09/08/2012                   MONTGOMERY         MD   DEPT OF HIGHWAYS

            TREE DOWN NEAR I-495 AT THE ROCKVILLE EXIT 

0349 PM     TSTM WND DMG     2 SSW NEWINGTON         38.72N  77.21W
09/08/2012                   FAIRFAX            VA   NWS STORM SURVEY

            THE WINDOWS WERE BLOWN OUT ON 29 VEHICLES AT THE LORTON 
            STATION VRE PARKING LOT. THE DAMAGED CARS WERE LOCATED 
            ON THE NORTHEAST SIDE OF THE PARKING LOT. IN 
            ADDITION...SEVERAL TREES WERE DOWN NEAR THE PARKING LOT 
            THAT WERE 8 TO 12 INCHES IN DIAMTER. 

0351 PM     TSTM WND DMG     1 NNW ROSSLYN           38.90N  77.08W
09/08/2012                   DISTRICT OF COLUMB DC   BROADCAST MEDIA 

            TREE DOWN ON CANAL ROAD 

0351 PM     TSTM WND DMG     WESTMORELAND            38.09N  78.45W
09/08/2012                   ALBEMARLE          VA   911 CALL CENTER 

            A TREE WAS BLOWN DOWN AT 415 CARRSBROOK DRIVE. 

0356 PM     TSTM WND GST     1 S REAGAN NATIONAL AIR 38.85N  77.03W
09/08/2012  M58 MPH          ARLINGTON          VA   ASOS            

0358 PM     TSTM WND DMG     1 NNW ALEXANDRIA        38.84N  77.10W
09/08/2012                   ARLINGTON          VA   BROADCAST MEDIA 

            TREE DOWN AT I-395 AND KING STREET 


0400 PM     TSTM WND DMG     1 WNW REAGAN NATIONAL A 38.86N  77.05W
09/08/2012                   ARLINGTON          VA   TRAINED SPOTTER 

            3 FT DIAMETER TREE DOWN 

0401 PM     TSTM WND GST     1 S REAGAN NATIONAL AIR 38.85N  77.03W
09/08/2012  M58 MPH          ARLINGTON          VA   ASOS            

0401 PM     TSTM WND DMG     BOLLING AIR FORCE BASE  38.84N  77.01W
09/08/2012                   DISTRICT OF COLUMB DC   TRAINED SPOTTER 

0402 PM     FUNNEL CLOUD     FORESTVILLE             38.85N  76.87W
09/08/2012                   PRINCE GEORGES     MD   LAW ENFORCEMENT 

            POLICE REPORTED FUNNEL CLOUD ALONG ALLENTOWN RD 

0405 PM     TSTM WND GST     2 ENE BELTSVILLE        39.05N  76.89W
09/08/2012  M59 MPH          PRINCE GEORGES     MD   MESONET         

0405 PM     TSTM WND GST     1 SW QUANTICO           38.51N  77.30W
09/08/2012  M58 MPH          PRINCE WILLIAM     VA   AWOS            

0407 PM     TSTM WND DMG     1 E CLINTON             38.76N  76.88W
09/08/2012                   PRINCE GEORGES     MD   TRAINED SPOTTER 

            MULTIPLE LARGE TREES...WITH BRANCHES UP TO 1 FOOT IN 
            DIAMETER...DOWNED IN FOX RUN ESTATES. 

0409 PM     TSTM WND GST     1 E MORNINGSIDE         38.83N  76.87W
09/08/2012  M59 MPH          PRINCE GEORGES     MD   AWOS            

0409 PM     TSTM WND GST     2 W GLENN DALE          38.99N  76.84W
09/08/2012  M58 MPH          PRINCE GEORGES     MD   MESONET         

0414 PM     TSTM WND DMG     2 SE BOWIE              38.94N  76.71W
09/08/2012                   PRINCE GEORGES     MD   DEPT OF HIGHWAYS

            TREE DOWN IN ROADWAY AT US 301 NORTH AT COLLINGTON RD 

0415 PM     TSTM WND DMG     2 ENE VERDIERSVILLE     38.29N  77.87W
09/08/2012                   ORANGE             VA   EMERGENCY MNGR  

            TREE DOWN ON BURR HILL RD AND RT 20. 

0419 PM     TSTM WND DMG     1 ESE BOWIE             38.96N  76.72W
09/08/2012                   PRINCE GEORGES     MD   TRAINED SPOTTER 

            TREE NEAR THE US 50 AND US 301 NORTH INTERCHANGE. 

0425 PM     TSTM WND DMG     3 SE DAVIDSONVILLE      38.90N  76.59W
09/08/2012                   ANNE ARUNDEL       MD   DEPT OF HIGHWAYS

            TREE DOWN AT RT 2 AND JORDAN TAYLOR LN 

0429 PM     TSTM WND DMG     1 SSW RIVA              38.93N  76.60W
09/08/2012                   ANNE ARUNDEL       MD   AMATEUR RADIO   

            SIX-INCH DIAMETER TREE DOWN BLOCKING ROAD 

0430 PM     FLASH FLOOD      WASHINGTON              38.91N  77.02W
09/08/2012                   DISTRICT OF COLUMB DC   911 CALL CENTER 

            PORTIONS OF MINNESOTA AVENUE AND NANNIE HELEN BURROUGHS 
            AVENUE CLOSED DUE TO FLASH FLOODING IN ASSOCIATION WITH 
            WATTS BRANCH. 

0430 PM     FLASH FLOOD      1 SW KENILWORTH         38.90N  76.95W
09/08/2012                   DISTRICT OF COLUMB DC   911 CALL CENTER 

            BENNING ROAD CLOSED DUE TO FLASH FLOODING IN 
            ASSOCIATION WITH WATTS BRANCH NEAR ROUTE 295. 

0440 PM     FUNNEL CLOUD     CAPE ST. CLAIRE         39.04N  76.45W
09/08/2012                   ANNE ARUNDEL       MD   AMATEUR RADIO   

            REPORTED BY LAW ENFORCEMENT 


&&

EVENT NUMBER LWX1201184 LWX1201176 LWX1201175 LWX1201174 LWX1201179 
LWX1201181 LWX1201178 LWX1201177 LWX1201182 LWX1201180 LWX1201191 
LWX1201195 LWX1201193 LWX1201210 LWX1201229 LWX1201199 LWX1201203 
LWX1201183 LWX1201186 LWX1201188 LWX1201202 LWX1201230 LWX1201207 
LWX1201226 LWX1201185 LWX1201216 LWX1201213 LWX1201209 LWX1201187 
LWX1201189 LWX1201212 LWX1201214 LWX1201227 LWX1201190 LWX1201204 
LWX1201225 LWX1201221 LWX1201228 LWX1201192 LWX1201220 LWX1201211 
LWX1201196 LWX1201223 LWX1201194 LWX1201197 LWX1201200 LWX1201217 
LWX1201198 LWX1201201 LWX1201205 LWX1201224 LWX1201222 LWX1201215 
LWX1201206 LWX1201218 LWX1201219 LWX1201208  

$$

JRK