Alert archive / Virginia / Flash Flood Warnings in 1993

Flash Flood Warning 49, NWS Baltimore/Washington

April 16, 1993Loudoun County, Virginia; Frederick County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Apr 16, 1993, 11:17 PM EDT for Loudoun County, Virginia; Frederick County, Maryland. It was in force for 118 min.

The area

The counties it named.

The facts

Issued
Apr 16, 1993, 11:17 PM EDT (03:17 UTC)
Expired
Apr 17, 1993, 1:15 AM EDT
In force
118 min
Issued by
NWS Baltimore/Washington
Area
Whole counties

Counties Frederick County, MD, Loudoun County, VA

The radar

The Sterling radar (KLWX), 34 km from the middle of the area, began a volume at 03:16 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, 3.3 hours before the alert went out and 38 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 1993-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 372 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 00:00Z on 1993-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.1939587897117Sfc1 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
372 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
626 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
-6 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.9

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
Apr 16, 8:13 PM EDTSevere Thunderstorm WarningLWXLoudoun47 min
Apr 16, 8:30 PM EDTTornado WarningLWXLoudoun30 min
Apr 16, 9:30 PM EDTFlash Flood WarningLWXFauquier, Loudoun2 hr
Apr 16, 9:33 PM EDTTornado WarningLWXLoudoun42 min
Apr 16, 9:56 PM EDTTornado WarningLWXFauquier34 min
Apr 16, 9:00 PM EDTSevere Thunderstorm WarningLWXFrederick45 min

Nearby

Flash Flood Warnings in Virginia, 1993Flash Flood Warnings in Maryland, 1993Every flash flood warning in 1993

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.