Alert archive / Virginia / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 21, NWS Baltimore/Washington

May 6, 19914 counties in Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at May 6, 1991, 4:35 PM EDT for 4 counties in Virginia. It was in force for 55 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 6, 1991, 4:35 PM EDT (20:35 UTC)
Expired
May 6, 1991, 5:30 PM EDT
In force
55 min
Issued by
NWS Baltimore/Washington
Area
Whole counties

Counties Culpeper County, VA, Fauquier County, VA, Loudoun County, VA, Rappahannock County, VA

What was reported inside it

TimeReportWhereRemark
May 6, 4:35 PM EDTThunderstorm Wind 0Loudoun, VA
May 6, 4:40 PM EDTThunderstorm Wind 0Fauquier, VA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.6 hours before the alert went out and 48 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 1991-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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 1991-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.193958Sfc1 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
13 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
559 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
33 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 
TTAA00 KWBC 062035
SVRWBC
VAC047-157-107-061-113-062130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE WASHINGTON DC
435 PM EDT MON MAY 6 1991
 
THE NATIONAL WEATHER SERVICE IN WASHINGTON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  530 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL VIRGINIA
 
   ...CULPEPER COUNTY...RAPPAHANNOCK COUNTY
 
IN NORTH VIRGINIA
 
   ...LOUDOUN COUNTY
 
IN NORTH CENTRAL VIRGINIA
 
   ...FAUQUIER COUNTY
 
IN WEST CENTRAL VIRGINIA
 
   ...MADISON COUNTY
 
AT 435 PM RADAR SHOWED A DEVELOPING AND INTENSIFYING LINE OF
THUNDERSTORMS FROM WESTERN LOUDOUN COUNTY ACROSS WESTERN FACQUIER
COUNTY TO JUST WEST OF CHARLOTTESVILLE VA. THE LINE WAS MOVING TOWARD
THE EAST AT 25 MPH. IN ADDITION WIND GUSTS IN EXCESS OF 58 MPH WERE
REPORTED 14 MILES NORTHWEST OF LEESBURG VA.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
A TORNADO WATCH IS ALSO IN tEFFECT FOR A PORTION OF THE WARNED AREA.  R
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING.  REMAIN CALM BUT BE ALERT TO
RAPIDLY CHANGING WEATHER CONDITIONS.
 
JLW

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 6, 2:56 PM EDT, 1 hour 39 minutes before
MDZ001>007- 062000-

NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
2.50PM EDT MON MAY 6 1991

 ...THUNDERSTORMS DEVELOPING OVER NORTHEAST MARYLAND...

AT 2.45PM THE NATIONAL WEATHER SERVICE WEATHER RADAR INDICATED SMALL CLUSTERS
OF RAINSHOWERS AND THUNDERSTROMS WERE DEVELOPING OVER ANNE ARUNDEL...BALTIMORE
...HARFORD AND CECIL COUNTIES IN NORTHEASTERN MARYLAND.

THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING BRIEF HEAVY DOWNPOURS AND  STRONG
GUSTY WINDS AS THEY MOVE TOWARD THE NORTHEAST AT 35 TO 40 MPH.

WEATHER CONDITIONS ARE RIPE FOR FURTHER THUNDERSTORM DEVELOPEMENT. AN
APPROACHING COLD FRONT HAD PRODUCED VERY HEAVY TO SEVERE THUNDERSTORMS
ACROSS WESTERN MARYLAND AS IT MOVES ACROSS MARYLAND.

THIS AREA IS EXPECTED TO MORE INTO CENTRAL AND EASTERN MARYLAND LATER THIS
AFTERNOON.  A SEVERE THUNDERSTORM OR TORNADO WATCH/WARNING IS ANTICIPATED
FOR THESE SECTIONS OF THE STATE AS THE FRONT APPROACHES.

RAD
Special weather statement, May 6, 3:16 PM EDT, 1 hour 19 minutes before
MDZ001>007- 062200-

NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
3.15PM EDT MON MAY 6 1991

 ...TORNADO WATCH FOR MOST OF MARYLAND AS THUNDERSTORMS MOVING INTO THE AREA...

A TORNADO WATCH HAS BEEN ISSUED EXTENDING FROM RICHMOND VIRGINIA TO PHILADELPHIAPENNSYLVANIA UNTIL 10PM TONIGHT.  THIS WATCH INCLUDES ALL MARYLAND COUNTIES EX-
CEPT GARRETT AND ALLEGHANY COUNTIES.

AT 3.00PM RAINSHOWERS AND THUNDERSTORMS WERE APPEARING ON THE NATIONAL WEATHER
SERVICE RADAR AT PAXUXENT RIVER MARYLAND.  THE SHOWERS AND THUNDERSTORMS WERE
MOVING TOWARD THE NORTHEAST AT 35 TO 40 MPH.

INCLUDED IN A TORNADO WATCH IS THE STRONG LIKELIHOOD FOR SEVERE THUNDERSTORMS
ACCOMPANIED BY STRONG GUSTY WINDS...HAIL...AND HEAVY DOWNPOURS. PRECAUTIONS
SHOULD BE TAKEN NOW TO MINIMIZE THE DANGERS FOR THE IMPENDING STORMS.

RAD
Special weather statement, May 6, 4:04 PM EDT, 31 minutes before
MDZ001>007- 062100-

NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
410 PM EDT MON MAY 6 1991

 ...TORNADO WATCH IN EFFECT FROM 4PM TO 10 PM...

A TORNADO WATCH HAS BEEN ISSUED FOR ALL OF MARYLAND EXCEPT ALLEGHENY AND
GARRETT COUNTIES...

AT 400 PM STRONG THUNDERSTORMS WERE REPORTED IN THE HAGERSTOWN AREA.
THESE THUNDERSTORMS WERE MOVING TO THE EAST NORTHEAST AT 35 TO 40 MPH.
THESE STORMS HAVE A HISTORY OF SEVERE WEATHER WITH WIND GUSTS TO 66 MPH
AND 1 INCH HAIL AND TREES DOWN IN PARTS OF VA. AND W.VA.

THE WEATHER SERVICE WILL BE MONITORING THESE STORMS AS THEY ADVANCE ACROSS
THE STATE AND WARNINGS WILL BE ISSUED AS NEEDED. STAY TUNED TO NOAA WEATHER
RADIO AND THE LOCAL ?MEDIA FOR FUTHER UPDATES AND BULLETINS.

FAD
Special weather statement, May 6, 4:23 PM EDT, 12 minutes before
MDZ001>007- 062100-

NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
420 PM EDT MON MAY 6 1991

 ...TORNADO WATCH IN EFFECT FROM 4PM TO 10 PM...

A TORNADO WATCH HAS BEEN ISSUED FOR ALL OF MARYLAND EXCEPT ALLEGHENY AND
GARRETT COUNTIES...

AT 415 PM STRONG THUNDERSTORMS WERE REPORTED IN WASHINGTON AND FREDERICK
COUNTIES. THESE THUNDERSTORMS WERE MOVING EAST NORTHEAST AT 35 TO 40 MPH.
WIND GUSTS OF 70 MPH WERE REPORTED IN BLUE RIDGE SUMMIT AND 50 MPH IN
JEFFERSON BOTH IN FREDERICK CO.

PERSON IN CARROLL COUNTY SHOULD BE ON THE ALERT FOR THE POSSIBILITY OF
STRONG WINDS IN THE NEXT HOUR. STAY TUNED TO NOAA WEATHER RADIO AND
THE LOCAL MEDIA FOR FUTHER UPDATES AND BULLETINS.
_
FAD

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 2:56 PM EDTSevere Thunderstorm WarningLWXFrederick49 min
May 6, 2:56 PM EDTSevere Thunderstorm WarningLWXCity of Winchester49 min
May 6, 3:52 PM EDTSevere Thunderstorm WarningLWXLoudoun68 min
May 6, 3:52 PM EDTSevere Thunderstorm WarningLWXClarke68 min
May 6, 4:35 PM EDTSevere Thunderstorm WarningLWXMadison55 min
May 6, 4:50 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, City of Alexandria, City of Falls Church55 min
May 6, 4:50 PM EDTSevere Thunderstorm WarningLWXPrince William, Stafford55 min
May 6, 4:50 PM EDTSevere Thunderstorm WarningLWXCity of Fairfax55 min
May 6, 4:50 PM EDTSevere Thunderstorm WarningLWXCity of Manassas, City of Manassas Park55 min

Nearby

Severe Thunderstorm Warnings in Virginia, 1991Every severe thunderstorm warning in 1991

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.