Alert archive / Virginia / Flash Flood Warnings in 1998

Flash Flood Warning 99, NWS Baltimore/Washington

March 20, 19987 counties in Virginia

NWS Baltimore/Washington issued this flash flood warning at Mar 20, 1998, 8:24 PM EST for 7 counties in 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

Counties Clarke County, VA, Fauquier County, VA, Frederick County, VA, Page County, VA, Rappahannock County, VA, Shenandoah County, VA, Warren County, VA

The radar

The Sterling radar (KLWX), 64 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

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 WarningLWXCity of Winchester2 hr
Mar 20, 8:24 PM ESTFlash Flood WarningLWXLoudoun2 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
Mar 20, 8:24 PM ESTFlash Flood WarningLWXBerkeley, Jefferson2 hr
Mar 20, 10:56 PM ESTFlash Flood WarningLWXGrant, Hampshire, Hardy2 hr
Mar 21, 12:57 AM ESTFlash Flood WarningLWXBerkeley2 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.