Alert archive / Virginia / Flash Flood Warnings in 1998

Flash Flood Warning 101, NWS Baltimore/Washington

March 20, 1998City of Winchester, Virginia

NWS Baltimore/Washington issued this flash flood warning at Mar 20, 1998, 8:24 PM EST for City of Winchester, Virginia. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Mar 20, 1998, 8:24 PM EST (01:24 UTC)
Expired
Mar 20, 1998, 10:50 PM EST
In force
2 hr
Issued by
NWS Baltimore/Washington
Area
Whole counties

County City of Winchester, VA

The radar

The Sterling radar (KLWX), 63 km from the middle of the area, began a volume at 01:23 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.4 hours before the alert went out and 71 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 00:00Z on 1998-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1998-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 255 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
448 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
255 m²/s²
0-3 km storm-relative helicity
420 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 210125
FFWWBC
VAC043-061-069-107-139-157-171-187-840-WVC003-037-210350-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON DC
824 PM EST FRI MAR 20 1998

THE BALTIMORE/WASHINGTON DC NATIONAL WEATHER SERVICE HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1050 PM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN NORTHEASTERN WEST VIRGINIA

   ...BERKELEY COUNTY
   ...JEFFERSON COUNTY

IN NORTHWESTERN VIRGINIA

   ...SHENANDOAH COUNTY
   ...FREDERICK COUNTY IN VIRGINIA
   ...PAGE COUNTY
   ...WARREN COUNTY
   ...CLARKE COUNTY
   ...RAPPAHANNOCK COUNTY
   ...THE INDEPENDENT CITY OF WINCHESTER
   ...WESTERN LOUDOUN COUNTY
   ...NORTHERN FAUQUIER COUNTY
 
AT 820 PM DOPPLER WEATHER RADAR INDICATED A LARGE AREA OF RAIN AND
THUNDERSTORMS EXTENDING FROM WEST CENTRAL VIRGINIA NORTHWARD
THROUGH NORTHWESTERN VIRGINIA AND THE EXTREME EASTERN PORTION OF
THE WEST VIRGINIA PANHANDLE.

AUTOMATED RAIN GAGES INDICATE THAT 1.5 TO 2.0 INCHES OF RAIN HAS
FALLEN IN THE WARNING AREA DURING THE PAST FEW HOURS. A WEATHER
SPOTTER FROM FREDERICK COUNTY VIRGINIA REPORTED A MUD AND ROCK
SLIDE ON ROUTE 50 IN GORE VIRGINIA WHICH IS JUST WEST OF
WINCHESTER.

ADDITIONAL RAIN AND THUNDERSTORMS WILL BE MOVING OVER THE WARNING
AREA DURING THE NEXT ONE TO TWO HOURS. THE ADDITIONAL RAINFALL
ON ALREADY SATURATED GROUND WILL RESULT IN FLOODING. ADDITIONAL
MUDSLIDES ARE POSSIBLE WHERE HEAVY RAIN OCCURS.
 
IF FLASH FLOODING IS OBSERVED...ACT QUICKLY.  MOVE TO ESCAPE FLOOD
WATERS.  DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS
RISING.

NEVER TO CROSS A FLOODED ROAD. THE WATER DEPTH COULD BE TOO GREAT
TO CROSS SAFELY. 

&

WALSTON/THEDE

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 20, 7:27 PM ESTFlash Flood WarningLWXGreene, Madison118 min
Mar 20, 7:27 PM ESTFlash Flood WarningLWXAlbemarle118 min
Mar 20, 8:24 PM ESTFlash Flood WarningLWXLoudoun2 hr
Mar 20, 8:24 PM ESTFlash Flood WarningLWXClarke, Fauquier, Frederick, Page, Rappahannock, Shenandoah and 1 more2 hr
Mar 20, 10:46 PM ESTFlash Flood WarningLWXClarke, Fauquier, Loudoun, Rappahannock, Warren2 hr
Mar 20, 10:46 PM ESTFlash Flood WarningLWXFrederick2 hr
Mar 20, 10:46 PM ESTFlash Flood WarningLWXCity of Winchester2 hr
Mar 21, 12:57 AM ESTFlash Flood WarningLWXFauquier, Loudoun2 hr

Nearby

Flash Flood Warnings in Virginia, 1998Every flash flood warning in 1998

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.