Alert archive / Virginia / Tornado Watches in 2008

Tornado Watch 403

May 31, 20087 counties in Maryland; 55 counties in Virginia

The Storm Prediction Center issued this tornado watch at May 31, 2008, 3:07 PM EDT for 7 counties in Maryland; 55 counties in Virginia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 31, 2008, 3:07 PM EDT (19:07 UTC)
Expired
May 31, 2008, 9:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 62 counties

Calvert County, MD, Charles County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Accomack County, VA, Albemarle County, VA, Amelia County, VA, Augusta County, VA, Buckingham County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Poquoson, VA, City of Richmond, VA, City of Staunton, VA, City of Waynesboro, VA, City of Williamsburg, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Henrico County, VA, Highland County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Madison County, VA, Mathews County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, York County, VA

The radar

The Sterling radar (KLWX), 86 km from the middle of the area, began a volume at 19:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 31, 3:11 PM EDTSevere Thunderstorm WarningLWXOrange, Spotsylvania, Stafford, City of Fredericksburg64 min
May 31, 3:13 PM EDTSevere Thunderstorm WarningAKQFluvanna, Goochland, Hanover, Louisa47 min
May 31, 3:21 PM EDTSevere Thunderstorm WarningAKQDorchester, Wicomico54 min
May 31, 3:25 PM EDTSevere Thunderstorm WarningAKQCaroline80 min
May 31, 3:30 PM EDTSevere Thunderstorm WarningLWXCalvert, Charles, Prince George's, Saint Mary's75 min
May 31, 3:57 PM EDTSevere Thunderstorm WarningAKQGoochland, Hanover, Henrico, King William, Louisa, Powhatan and 1 more63 min
May 31, 3:59 PM EDTSevere Thunderstorm WarningAKQDorchester39 min
May 31, 4:09 PM EDTTornado WarningAKQCaroline20 min
May 31, 4:27 PM EDTSevere Thunderstorm WarningAKQCaroline, Essex, King and Queen, King William, Richmond, Westmoreland63 min
May 31, 4:48 PM EDTTornado WarningAKQCaroline, Essex, Hanover, King and Queen, King William23 min
May 31, 5:02 PM EDTSevere Thunderstorm WarningAKQHanover, King William43 min
May 31, 5:10 PM EDTTornado WarningAKQKing and Queen17 min
May 31, 5:14 PM EDTSevere Thunderstorm WarningAKQKing William28 min
May 31, 5:19 PM EDTSevere Thunderstorm WarningAKQKing and Queen, Lancaster, Middlesex, Northumberland, Richmond, Westmoreland71 min
May 31, 5:40 PM EDTSevere Thunderstorm WarningAKQKing and Queen, King William18 min
May 31, 5:46 PM EDTSevere Thunderstorm WarningAKQAccomack73 min
May 31, 6:23 PM EDTSevere Thunderstorm WarningAKQGloucester, King and Queen, King William, Mathews, Middlesex, New Kent52 min
May 31, 6:30 PM EDTSevere Thunderstorm WarningAKQNorthampton90 min
May 31, 7:06 PM EDTSevere Thunderstorm WarningAKQMathews20 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.1 hours before the alert went out and 85 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2008-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 658 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2008-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
658 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
165 m²/s²
Significant tornado parameter
0.4
Supercell composite
6.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000
WWUS20 KWNS 311907
SEL3  
SPC WW 311907
MDZ000-VAZ000-WVZ000-CWZ000-010100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 403
NWS STORM PREDICTION CENTER NORMAN OK
310 PM EDT SAT MAY 31 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       SOUTHERN MARYLAND
       VIRGINIA
       PART OF THE EASTERN WEST VIRGINIA PANHANDLE
       COASTAL WATERS

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 310 PM UNTIL
900 PM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 20 MILES WEST OF STAUNTON
VIRGINIA TO 10 MILES SOUTH SOUTHEAST OF WALLOPS VIRGINIA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 402...

DISCUSSION...HEIGHT FALLS/ASCENT ASSOCIATED WITH STRONG UPPER TROUGH
MOVING ACROSS THE ERN GREAT LAKES WILL INCREASE THUNDERSTORMS OVER
THIS REGION THIS EVENING AS TROUGH SHIFTS EWD.  AIR MASS IS VERY
UNSTABLE SOUTH OF OUTFLOW BOUNDARY NOW PUSHING INTO FAR NRN VA/NERN
MD/DE WITH MLCAPES AOA 2000 J/KG.  GIVEN STRONG DEEP LAYER
SHEAR...EXPECT ACTIVITY WILL ORGANIZE INTO LINES/SUPERCELLS WITH
THREATS OF LARGE HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 28035.


...EVANS

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 31, 4:10 AM EDTTornado WatchSPCGarrett6 hr
May 31, 8:54 AM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Carroll, Cecil, Frederick, Harford and 6 more96 min
May 31, 10:20 AM EDTTornado WatchSPCAllegany, Anne Arundel, Baltimore, Caroline, Carroll, Cecil and 11 more7 hr
May 31, 12:05 PM EDTMesoscale DiscussionSPCSaint Mary's, Somerset55 min
May 31, 4:28 PM EDTMesoscale DiscussionSPCGarrett62 min
May 31, 4:04 PM EDTMesoscale DiscussionSPCBrunswick, Dinwiddie, Greensville, Isle of Wight, Lunenburg, Mecklenburg and 7 more56 min
May 31, 4:23 PM EDTTornado WatchSPCAppomattox, Brunswick, Campbell, Charlotte, Dinwiddie, Greensville and 23 more4 hr
May 31, 6:19 PM EDTMesoscale DiscussionSPCLee56 min
May 31, 7:37 PM EDTMesoscale DiscussionSPCAccomack, Brunswick, Caroline, Charles City, Chesterfield, Dinwiddie and 36 more53 min

Nearby

Tornado Watches in Virginia, 2008Tornado Watches in Maryland, 2008Every tornado watch in 2008

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.