Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 3, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 6, 1991, 5:43 PM EDT for Chester County, Pennsylvania. It was in force for 32 min.
The area
The counties it named.
The facts
- Issued
- May 6, 1991, 5:43 PM EDT (21:43 UTC)
- Expired
- May 6, 1991, 6:15 PM EDT
- In force
- 32 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
County Chester County, PA
The nearest sounding before it
Atlantic City In, NJ (KACY), launched 12:00Z, 9.7 hours before the alert went out and 122 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 574 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 224 m²/s²
- 0-3 km storm-relative helicity
- 288 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KPHL 062145 SVRPHL PAC029-062215- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PHILADELPHIA PA 543 PM EDT MON MAY 6 1991 THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 615 PM EDT FOR PEOPLE IN THE FOLLOWING LOCATION... IN SOUTHEAST PENNSYLVANIA ...CHESTER COUNTY AT 540 PM WEATHER SERVICE RADAR INDICATED A LINE OF THUNDERSTORMS MOVING INTO WESTERN CHESTER COUNTY. THESE THUNDERSTORMS PRODUCED WIND GUSTS TO OVER 60 MPH AS THEY MOVED THROUGH LANCASTER COUNTY. HAIL IS ALSO POSSIBLE WITH THESE THUNDERSTORMS AS THEY MOVE THROUGH CHESTER COUNTY. A TORNADO WATCH CONTINUES FOR SOUTHEASTERN PENN6SYLVANIA AND SOUTHERN NEW JERSEY UNTIL 1000 PM EDT. REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCED WARNING.
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, May 6, 4:10 PM EDT, 1 hour 33 minutes before
061955-002-004-062100 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ATLANTIC CITY NJ 355 PM EDT MON MAY 06 1991 ...TORNADO WATCH IN EFFECT FOR SOUTHERN NEW JERSEY UNTIL 10 PM EDT... NO SEVERE WEATHER HAS BEEN DETECTED OVER SOUTHERN NEW JERSEY AT THIS TIME. MOIST AND UNSTABLE AIR OVER THE AREA IN ADVANCE OF A COLD FRONT THIS AFTERNOON. FRONT EXTENDED FROM LAKE ONTARIO INTO CENTRAL PENNSYLVANIA AND EASTERN WEST VIRGINIA THEN CONTINUED SOUTH INTO THE SOUTHEAST STATES. THIS FRON WILL CROSS SOUTHERN NEW JERSEY DURING THE EVENING. SEVERE THUNDERSTORMS AS WELL AS POSSIBLE TORNADOES MAY BE ASSOCIATED WITH THIS FRONT. THUNDERSTORMS MAY CONTAIN HEAVY DOWNPOURS...FREQUENT DANGEROUS LIGHTNING...POSSIBLE HAIL AND STRONG GUSTY WINDS. RESIDENTS SHOULD BE PREPARED TO SEEK SHELTER IF THREATNING APPROACHES. LIGHTNING AND ACCIDENTS ASSOCIATED WITH LIGHTNING KILL MORE PEOPLE EACH YEAR THAN ANY OTHER WEATHER EVENT. REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS TO DEVELOP IN AND CLOSE TO A WATCH AREA. PERSONS SOUTHERN NEW JERSEY SHOULD BE ON THE LOOKOUT FOR THREATNING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. BE PREPARED TO SEEK SHELTER IF SEVERE WEATHER APPROACHES. BUDMAN/BUBBA
Special weather statement, May 6, 4:44 PM EDT, 59 minutes before
061955-002-004-062200 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ATLANTIC CITY NJ 435 PM EDT MON MAY 06 1991 ...TORNADO WATCH IN EFFECT FOR SOUTHERN NEW JERSEY UNTIL 10 PM EDT... NO SEVERE WEATHER HAS BEEN DETECTED OVER SOUTHERN NEW JERSEY AT THIS TIME. SEVERE THUNDERSTORMS HAVE BEEN REPORTED IN WESTERN PENNSYLVANIA WITH WIND GUSTS TO 62 MAH AND HAIL STONES TO 1/4 INCH. AT 430 PM...OUR WEATRHER SEARCH RADAR INDICATED SCATTERED SHOWERS FROM MANASQUAN COASTAL CENTRAL NEW JERSEY ACROSS TO SALEM IN SOUTHWEST NEQ JERSEY. ALSO SHOWERE WERE SCATTERED OVER EASTERN AND SOUTHEAST PENNSYLAVNIA. SHOWERS AND THUNDERSTORMS WERE DETECTED IN A BAND ABOUT 30 MILES WIDE FROM CENTRAL PENNSYLVANIA INTO NORTHWEST MARYLAND. HEAVIEST STORM WERE INDICATED IN PENNSYLVANIA JUST TO THE WEST OF GETTSBURG AND HARRISBURG. MOVEMENT WAS TO THE NORTHEAST AT 35 MILES AN HOUR. REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS TO DEVELOP IN AND CLOSE TO A WATCH AREA. PERSONS SOUTHERN NEW JERSEY SHOULD BE ON THE LOOKOUT FOR THREATNING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. BE PREPARED TO SEEK SHELTER IF SEVERE WEATHER APPROACHES. FXD/WS/PM
Special weather statement, May 6, 4:58 PM EDT, 45 minutes before
PAZ011-016-062200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ALLENTOWN PA 445 PM EDT MON MAY 6 1991 ...TORNADO WATCH IN EFFECT UNTIL 10 PM EDT FOR BERKS COUNTY... ...SEVERE THUNDERSTORM WATCH UNTIL 10 PM EDT FOR EAST CENTRAL PENNSYLVANIA... THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WATCH FOR BERKS COUNTY UNTIL 10 PM AND A SEVERE THUNDERSTORM WATCH FOR BERKS... LEHIGH...NORTHAMPTON...SCHUYLKILL...CARBON...MONROE AND PIKE COUNTIES. THE THREAT OF SEVERE THUNDERSTORMS WITH DAMAGING WINDS...LARGE HAIL AND DANGEROUS LIGHTNING EXIT IN AND CLOSE TO THE WATCH AREA UNTIL 10 PM EDT. AT 445 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF HEAVY THUNDERSTORMS EXTENDING FROM WILLIAMSPORT SOUTH TO HARRISBURG. THE LINE IS MOVING EAST AT ABOUT 40 MPH AND WILL MOVE THROUGH EASTERN PENNSYLVANIA BETWEEN 6 AND 10 PM. REMEMBER...A TORNADO AND SEVERE THUNDERSTORM WATCH MEAN CONDITIONS ARE FAVORABLE FOR THE DEVELOPMENT OF TORNADOES AND SEVERE THUNDERSTORMS. PEOPLE LIVING IN EAST CENTRAL AND SOUTHEAST PENNSYLVANIA SHOULD BE ALERT FOR THREATENING WEATHER. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO AND TELEVISION STATIONS FOR THE LATEST INFORMATION ON THIS WEATHER SITUATION. DOVICO
Special weather statement, May 6, 5:23 PM EDT, 20 minutes before
PAZ007>012-016-NJZ002>004-006-062300- SEVERE WEATHER STATEMENT - NATIONAL WEATHER SERVICE PHILADELPHIA PA 530 PM EDT MON MAY 6 1991 ...TORNADO WATCH IN EFFECT FOR SOUTHEAST PENNSYLVANIA AND MOST OF SOUTHERN NEW JERSEY TIL 10 PM EDT... AT 5 15 PM AN AREA OF SHOWERS AND STRONG THUNDERSTORMS EXTENDED FROM WESTERN NEW YORK STATE TO SOUTHWEST NORTH CAROLINA. IN PENNSYLVANIA THE LEADING EDGE OF THE STORMS EXTENDED FROM BRADFORD COUNTY IN THE NORTH TO LANCASTER COUNTY IN THE SOUTH. THE STORMS ARE MOVING EAST NORTHEAST AT 45 MILES AN HOUR. SOME INDIVIDUAL STORMS ARE MOVING AS FAST AS 55 MILES AN HOUR. FOR THE NEXT COUPLE OF HOURS THESE STORMS WILL BE MOVING VERY QUICKLY ACROSS CENTRAL AND EASTERN PENNSYLVANIA AND INTO NEW JERSEY. TORNADOES...STRONG WIND GUSTS...HAIL...AND DANGEROUS LIGHTNING CAN BE EXPECTED WITH THESE STORMS. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO AND TELEVISION STATIONS THIS AFTERNOON AND EVENING FOR ANY ADDITIONAL SEVERE WEATHER WATCHES...WARNINGS OR STATEMENTS. JEJ
Special weather statement, May 6, 5:25 PM EDT, 18 minutes before
PAZ007>012-016-NJZ002>004-006-062300- SEVERE WEATHER STATEMENT - NATIONAL WEATHER SERVICE PHILADELPHIA PA 530 PM EDT MON MAY 6 1991 ...TORNADO WATCH IN EFFECT FOR SOUTHEAST PENNSYLVANIA AND MOST OF SOUTHERN NEW JERSEY TIL 10 PM EDT... AT 5 15 PM AN AREA OF SHOWERS AND STRONG THUNDERSTORMS EXTENDED FROM WESTERN NEW YORK STATE TO SOUTHWEST NORTH CAROLINA. IN PENNSYLVANIA THE LEADING EDGE OF THE STORMS EXTENDED FROM BRADFORD COUNTY IN THE NORTH TO LANCASTER COUNTY IN THE SOUTH. THE STORMS ARE MOVING EAST NORTHEAST AT 45 MILES AN HOUR. SOME INDIVIDUAL STORMS ARE MOVING AS FAST AS 55 MILES AN HOUR. FOR THE NEXT COUPLE OF HOURS THESE STORMS WILL BE MOVING VERY QUICKLY ACROSS CENTRAL AND EASTERN PENNSYLVANIA...INCLUDING THE PHILADELPHIA METROPOLITAN AREA...AND INTO SOUTHERN NEW JERSEY. TORNADOES...STRONG WIND GUSTS...HAIL...AND DANGEROUS LIGHTNING CAN BE EXPECTED WITH THESE STORMS. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOC AL RADIO AND TELEVISION STATIONS THIS AFTERNOON AND EVENING FOR ANY ADDITIONAL SEVERE WEATHER WATCHES...WARNINGS OR STATEMENTS. JEJ
Special weather statement, May 6, 5:28 PM EDT, 15 minutes before
DEZALL-062300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILMINGTON DE 528 PM EDT MON MAY 6 1991 ...THUNDERSTORMS HEADING FOR THE FIRST STATE... ...TORNADO WATCH IN EFFECT UNTIL 10 PM EDT TONIGHT... AT 515 PM WEATHER RADAR SHOWED A LINE OF THUNDERSTORMS EXTENDING FROM 40 MILES NORTHWEST OF THE NEW CASTLE COUNTY AIRPORT TO 15 MILES WEST OF BALTIMORE TO JUST WEST OF WASHINGTON AND SOUTHWARD INTO VIRGINIA. THESE ARE MOVING EAST AT 30 MPH AND WILL BE REACHING NORTHERN DELAWARE AROUND 630 PM...AND A LITTLE LATER FROM 7PM TO 8PM DOWNSTATE. THESE THUNDERSTORMS HAVE BEEN PRODUCING SOME STRONG GUSTY WINDS AND RADAR INDICATES THE POSSIBILITY OF HAIL IN SOME OF THESE THUNDERSTORMS. IN THE HARRISBURG AREA...WINDS GUSTED TO 52 MPH SHORTLY BEFORE 5PM IN A HEAVY SHOWER...AND AT DULLES AIRPORT WINDS GUSTED TO 40 MPH. NO TORNADOES HAVE BEEN SIGHTED AS YET...BUT A TORNADO WATCH IS IN EFFECT FOR ALL OF DELAWARE UNTIL 10PM. SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE WARNING. PERSONS IN THE WATCH AREA SHOULD BE ALERT AND PREPARED TO TAKE PROTECTIVE MEASURES IMMEDIATELY WHEN THE THUNDERSTORMS REACH THE STATE. LISTEN FOR LATER STATEMENTS OR WARNINGS ON NOAA WEATHER RADIO OR LOCAL TV AND RADIO STATIONS. CS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 6, 6:06 PM EDT | Severe Thunderstorm Warning | PHI | Montgomery | 54 min |
| May 6, 6:48 PM EDT | Severe Thunderstorm Warning | PHI | Philadelphia | 27 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 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.