Alert archive / Virginia / Tornado Watches in 2003

Tornado Watch 925

September 18, 2003Saint Mary's County, Somerset County, Worcester County, Maryland; 19 counties in North Carolina; 31 counties in Virginia

The Storm Prediction Center issued this tornado watch at Sep 18, 2003, 8:25 AM EDT for Saint Mary's County, Somerset County, Worcester County, Maryland; 19 counties in North Carolina; 31 counties in Virginia. It was in force for 12 hr.

The area

The outline as issued.

The facts

Issued
Sep 18, 2003, 8:25 AM EDT (12:25 UTC)
Expired
Sep 18, 2003, 8:00 PM EDT
In force
12 hr
Issued by
the Storm Prediction Center
All 53 counties

Saint Mary's County, MD, Somerset County, MD, Worcester County, MD, Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Gates County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Martin County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC, Accomack County, VA, Charles City County, VA, City of Chesapeake, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 91 km from the middle of the area, began a volume at 12:28 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 18, 12:45 PM EDTFlash Flood WarningMHXCarteret, Craven, Pamlico4 hr
Sep 18, 3:00 PM EDTFlash Flood WarningMHXHyde3 hr
Sep 18, 6:12 PM EDTTornado WarningAKQCity of Norfolk28 min
Sep 18, 6:29 PM EDTTornado WarningAKQWorcester16 min
Sep 18, 6:30 PM EDTTornado WarningAKQWorcester15 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

Newport, NC (KMHX), launched 12:00Z, 0.4 hours before the alert went out and 162 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, Newport, NC at 12:00Z on 2003-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Newport, NC at 12:00Z on 2003-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 184 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
543 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
276 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 181233
SEL5  
SPC WW 181225
MDZ000-NCZ000-VAZ000-CWZ000-190000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 925 
NWS STORM PREDICTION CENTER NORMAN OK 
825 AM EDT THU SEP 18 2003

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

       EASTERN SHORE OF MARYLAND
       EASTERN NORTH CAROLINA
       SOUTHEAST VIRGINIA
       COASTAL WATERS

EFFECTIVE THIS THURSDAY MORNING AND EVENING FROM 825 AM UNTIL 800
PM EDT.

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

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 25 MILES EAST NORTHEAST OF PATUXENT RIVER MARYLAND
TO 25 MILES SOUTHEAST OF NEW BERN NORTH CAROLINA.

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.




DISCUSSION...HURRICANE ISABEL IS EXPECTED TO MAKE LANDFALL ON THE
SRN OUTER BANKS OF NC THIS AFTERNOON.  N OF THE STORM TRACK...RICH
LOW-LEVEL MOISTURE WILL SPREAD GRADUALLY INLAND FROM NE NC BY MID
MORNING TO SE VA AND SE MD BY EARLY AFTERNOON...ALONG AND E OF A
WEAK WARM FRONT THAT EXTENDS NNEWD FROM THE CENTER OF THE HURRICANE.
 ONCE THE LOW LEVELS DESTABILIZE INLAND...VERY STRONG LOW-LEVEL
SHEAR WILL SUPPORT A THREAT OF RAINBAND MINI SUPERCELLS WITH A FEW
TORNADOES THROUGH THIS EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 08040.


...THOMPSON

382,0745 344,0754 344,0774 382,0770

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 18, 4:04 AM EDTMesoscale DiscussionSPCDorchester, Somerset, Wicomico, Worcester3 hr
Sep 18, 7:44 AM EDTMesoscale DiscussionSPCCalvert, Dorchester, Saint Mary's, Somerset, Talbot, Wicomico and 1 more2 hr
Sep 18, 12:03 PM EDTMesoscale DiscussionSPCSaint Mary's, Somerset, Worcester117 min
Sep 18, 4:03 PM EDTMesoscale DiscussionSPCSaint Mary's, Somerset, Wicomico, Worcester117 min
Sep 18, 6:44 PM EDTMesoscale DiscussionSPCCalvert, Charles, Dorchester, Saint Mary's, Somerset91 min

Nearby

Tornado Watches in Virginia, 2003Tornado Watches in North Carolina, 2003Tornado Watches in Maryland, 2003Every tornado watch in 2003

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.