Alert archive / Maryland / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 21, NWS Baltimore/Washington

April 16, 1993Frederick County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Apr 16, 1993, 9:00 PM EDT for Frederick County, Maryland. It was in force for 45 min.

The area

The counties it named.

The facts

Issued: Apr 16, 1993, 9:00 PM EDT (01:00 UTC)
Expired: Apr 16, 1993, 9:45 PM EDT
In force: 45 min
Issued by: NWS Baltimore/Washington
Area: Whole counties

County Frederick County, MD

The radar

The Sterling radar (KLWX), 56 km from the middle of the area, began a volume at 01:01 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, 1.0 hours before the alert went out and 58 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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

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

000 
WUUS1 KWBC 170102 RRA
SVRWBC
MDC021-170145-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE WASHINGTON DC
900 PM EDT FRI APR 16 1993
 
THE NATIONAL WEATHER SERVICE IN WASHINGTON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  945 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH CENTRAL MARYLAND
 
   ...FREDERICK COUNTY
 
WEATHER SERVICE DOPPLER RADAR INDICATES AN AREA OF THUNDERSTORMS IN
NORTHERN LOUDOUN COUNTY VIRGINIA...MOVING NORTHEAST AT 35 MPH. THESE
THUNDERSTORMS ARE CAPABLE OF PRODUCING LARGE HAIL AND STRONG GUSTY
WINDS. THE ENVIRONMENT IS ALSO FAVORABLE FOR THE FORMATION OF TORNADOES
WITH THESE STORMS.
 
THE MOST INTENSE STORMS ARE HEADING FOR CENTRAL FREDERICK
COUNTY...TOWARDS THE CITY OF FREDERICK.  THE FREDERICK AREA WILL BE
AFFECTED BY THESE THUNDERSTORMS IN THE NEXT 15 MINUTES OR SO.
 
A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA.  REMEMBER
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING.  REMAIN CALM BUT BE ALERT TO
RAPIDLY CHANGING WEATHER CONDITIONS.
 
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.

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 16, 9:30 PM EDT	Flash Flood Warning	LWX	Frederick	2 hr
Apr 16, 11:17 PM EDT	Flash Flood Warning	LWX	Frederick	118 min

Nearby

Severe Thunderstorm Warnings in Maryland, 1993 Every severe thunderstorm 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.