Alert archive / New Jersey / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 47, NWS Philadelphia/Mount Holly

August 20, 1991Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 20, 1991, 3:45 PM EDT for Salem County, New Jersey. It was in force for 45 min.

The area

The counties it named.

The facts

Issued
Aug 20, 1991, 3:45 PM EDT (19:45 UTC)
Expired
Aug 20, 1991, 4:30 PM EDT
In force
45 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Salem County, NJ

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 7.8 hours before the alert went out and 75 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, Atlantic City In, NJ at 12:00Z on 1991-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 772 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, Atlantic City In, NJ at 12:00Z on 1991-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.1939587897Sfc1 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
772 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 201945
SVRPHL
NJC033-202030-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE PHILADELPHIA PA
345 PM EDT TUE AUG 20 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 430 PM EDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE SOUTHWEST PART OF NEW JERSEY
      SALEM

AT 340PM  RADAR INDICATED A SEVERE THUNDERSTORM OVER SALEM
COUNTY NEAR WOODSTOWN MOVING SLOWLY NORTH.

  WEATHER SPOTTER RPORTED 60 MPH WINDS AND EXTREMELY HEAVY RAINS.

 THIS IS A DANGEROUS STORM AND PEOPLE IN THE WARNED AREA SHOULD BE
PREPARED FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN
AND LIGHTNING. SHOULD THE STORM APPROACH YOU...SEEK IMMEDIATE
SHELTER. MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS AND
SHOULD BE AVOIDED.

 A SEVERE THUNDERSTORM WATCH CONTINUES FOR IN EFFECT FOR ALL OF
 SOUTHERN NEW JERSEY UNTIL 5 PM EDT.

 HEAVY RAINS WITH THIS THUNDERSTORM MAY CAUSE FLKOODING
 OF SMALL STREAMS AND UNDERPASSES.

 WN

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, Aug 20, 12:34 PM EDT, 3 hours 11 minutes before
PAZ011-016-201730-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ALLENTOWN PA
1225 PM EDT TUE AUG 20 1991

...SMALL STREAM AND URBAN FLOOD WATCH FOR EAST CENTRAL PENNSYLVANA FOR
   THIS AFTERNOON AND EVENING...
...SEVERE THUNDERSTORM WATCH FOR EAST CENTRAL PENNSYLVANIA UNTIL 5 PM EDT...

AT 1225 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A 75 MILE
WIDE BAND OF HEAVY SHOWERS AND THUNDERSTORMS EXTENDED FROM LYCOMING
AND SULLIVAN COUNTIES IN NORTH CENTRAL PENNSYLVANIA SOUTHEAST TO LANCASTER...
...CHESTER AND PHILADELPHIA COUNTIES IN SOUTHEASTERN PENNSYLVANIA. THE
BAND IS MOVING EAST NORTHEAST AT 30 MPH AND WILL MOVE THROUGH EASTERN
PENNSYLVANIA BETWEEN 1230 PM AND 3 PM EDT. HEAVY DOWNPOURS MAY RESULT IN
SMALL STREAM AND URBAN FLOODING.

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR EAST CENTRAL PENNSYLVANIA
UNTIL 5 PM. THE WATCH AREA INCLUDES BERKS...SCHUYLKILL...LEHIGH...
NORTHAMPTON...CARBON AND MONROE COUNTIES.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN
THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS
AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS.

DOVICO
Special weather statement, Aug 20, 1:05 PM EDT, 2 hours 40 minutes before
NJZ002>004-200245

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
1230 PM EDT TUE AUG 20 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 500PM THIS AFTERNOON...

AT 1230 PM EDT...THE ATLANTIC CITY WEATHER RADAR DETECTED AN AREA OF
THUNDERSTORMS WITH VERY HEAVY RAIN OVER CHESTER AND MONTGOMERY COUNTIES
OF SOUTHEASTERN PENNSYLVANIA. IN CHESTER COUNTY...TWO INCHES OF RAIN
WAS REPORTED IN TWELVE MINUTES.

THESE STORMS WERE PART OF A LARGER AREA OF SHOWERS STRETCHING FROM
NORTHERN DELAWARE INTO NORTHEASTERN PENNSYLVANIA WITH THE HEAVIEST
ACTIVITY ABOUT 20 MILES NORTHWEST OF PHILADELPHIA.

SCATTERED SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN WERE OVER NORTHEASTERN
MARYLAND AND CENTRAL NEW JERSEY.
.
ELSEWHERE...SHOWERS AND THUNDERSTORMS WITH VERY HEAVY RAIN WERE OVER
THE OCEAN BETWEEN 50 AND 125 EAST OF THE NEW JERSEY AND DELMARVA COASTS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE THUNDERSTORM IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE
AREAS SHOULD BE ON THE OUTLOOK FOR THREATENING WEATHER CONDITIONS AND
LISTEN FOR FURTHER STATEMENTS AND POSSIBLE WARNINGS.

AT THIS TIME NO SEVERE WEATHER WAS OCCURRING IN SOUTHERN NEW JERSEY.

SJG/PM
Local storm report, Aug 20, 1:16 PM EDT, 2 hours 29 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
115 PM EDT TUE AUG 20 1991

PRELIMINARY HEAVY RAINFALL REPORTS FOR
TUE AUGUST 20 1991

TIME (EDT)   COUNTY         LOCATION         EVENT

1315    +    MONTGOMERY      GLENSIDE         2.15 INCHES IN 20 MIN.

WN
Special weather statement, Aug 20, 1:59 PM EDT, 1 hour 46 minutes before
NJZ002>004-200245

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
133 PM EDT TUE AUG 20 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 5PM EDT FOR ALL OF
SOUTHERN NEW JERSEY...

AT 133 PM EDT...THE ATLANTIC CITY WEATHER RADAR DETECTED AN AREA OF
THUNDERSTORMS WITH VERY HEAVY RAIN OVER BUCKS AND CHESTER COUNTIES
OF SOUTHEASTERN PENNSYLVANIA. AN ISOLATED THUNDERSTORM WITH VERY HEAVY
RAIN WAS ALSO IN SALEM COUNTY OF SOUTHERN NEW JERSEY. THESE STORMS
WERE PART OF A LARGER AREA OF SHOWERS THAT STRETCHED FROM SOUTHWESTERN
NEW JERSEY INTO NORTHEASTERN PENNSYLVANIA WITH THE HEAVIEST ACTIVITY
BETWEEN 10 AND 40 MILES NORTH OF PHILADELPHIA.

OTHER SCATTERED SHOWERS AND THUNDERSTORMS WERE OVER CENTRAL NEW JERSEY
AND NORTHEASTERN MARYLAND.
ELSEWHERE...SHOWERS AND THUNDERSTORMS WITH VERY HEAVY RAIN WERE OVER
THE OCEAN BETWEEN 50 AND 125 EAST OF THE NEW JERSEY AND DELMARVA COASTS.

MOVEMENT WAS NORTHEAST AT AROUND 30 MILES AN HOUR.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE THUNDERSTORM IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE
AREAS SHOULD BE ON THE OUTLOOK FOR THREATENING WEATHER CONDITIONS AND
LISTEN FOR FURTHER STATEMENTS AND POSSIBLE WARNINGS.

SJG/PM
Special weather statement, Aug 20, 2:52 PM EDT, 53 minutes before
NJZ002>004-201950-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
245 PM EDT TUE AUG 20 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 5PM EDT FOR ALL OF
SOUTHERN NEW JERSEY AND ADJACENT COASTAL WATERS...

AT 234 PM EDT...THE ATLANTIC CITY WEATHER RADAR DETECTED A SMALL BAND OF
POSSIBLE SEVERE THUNDERSTORMS WITH HAIL...INTENSE DOWNPOURS...GUSTY WINDS
AND FREQUENT DANGEROUS LIGHTNING IN NORTHERN NEW JERSEY EXTENDING FROM
SOUTHERN MORRIS COUNTY INTO SOMERSEY COUNTY AND MOVING INTO ESSEX AND UNION
COUNTIES. FLASH FLOOD WARNING HAVE BEEN ISSUED FOR THESE COUNTIES.
MOVEMENT WAS NORTHNORTHEAST AT 20 TO 25 MILES AN HOUR.

OTHER THUNDERSTORMS WITH VERY HEAVY RAINS AND POSSIBLE GUSTY WINDS WERE
INDICATED ALONG THE NORTHERN NEW JERSEY COASTA AND COASTAL WATERS FROM
SANDY HOOK TO MANASQUAN...CAMDEN AND MAPLE SHADE WESTERN SOUTHERN NEW JERSEY
...CHESTER COUNTY SOUTHEAST PENNSYLVANIA AND NEAR ANNAPOLIS MARYLAND.

SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAIN...WERE SCATTERED OVER
CENTRAL AND NORTHERN NEW JERSEY...EXTREME WESTERN SOUTHERN NEW JERSEY...
NORTHEAST INTO EASTERN AND SOUTHEAST PENNSYLVANIA...CENTRAL MARYLAND AND
OVER THE OCEAN FROM 25 TO 130 MILES EAST OF THE NEW JERSEY AND DELMARVA
COASTS. MOVEMENT WAS NORTHEAST AT 20 TO 25 MILES AN HOUR.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSO7NS IN THESE
AREAS SHOULD BE ON THE OUTLOOK FOR THREATENING WEATHER CONDITIONS AND
LISTEN FOR FURTHER STATEMENTS AND POSSIBLE WARNINGS.

SJG/PM/FXD
Special weather statement, Aug 20, 3:44 PM EDT, 1 minute before
DEZ003-002-202145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON DE
339 PM EDT TUE AUG 20 1991

...THUNDERSTORMS MOVING TOWARDS DELAWARE...

AS OF 330 PM EDT WEATHER SERVICE RADAR INDICATES THUNDERSTORMS
DEVELOPING RAPIDLY ACROSS THE STATE OF DELAWARE.  AN AREA OF
THUNDERSTORMS LOCATED IN QUEEN ANNES AND KENT COUNTIES OF MARYLAND
WILL BE MOVING TO THE NORTHEAST INTO NORTHERN KENT COUNTY AND NEW
CASTLE COUNTIES OF DELAWARE.  ANOTHER AREA OF STORMS ARE LOCATED IN
SOUTHERN NEW CASTLE COUNTY MOVING NORTHEAST ACROSS THE DELAWARE RIVER
INTO NEW JERSEY TOWARDS SALEM NEW JERSEY.

THESE STORMS ARE MOVING TO THE NORTH NORTHEAST AT ABOUT 30 TO 35 MPH.
THEY MAY BE ACCOMPANIED BY STRONG GUSTY WINDS...HEAVY RAIN...AND
DANGEROUS LIGHTNING.

IF YOU SEE THREATENING WEATHER APPROACHING SEEK SHELTER
IMMEDIATELY...AND LISTEN FOR THE LATEST INFORMATION ON LOCAL
TV...RADIO AND NOAA WEATHER RADIO.

THE STORMS IN MARYLAND WIXLL BE MOVING ACROSS NORTHERN DELAWARE WITHIN
THE NEXT 1 TO 2 HOURS.

VAUGHAN

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 1:45 PM EDTFlash Flood WarningPHIMercer60 min
Aug 20, 6:56 PM EDTFlash Flood WarningPHIMercer3 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 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; the sounding from the Mesonet's radiosonde archive.