Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 12, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 11, 1991, 9:29 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 46 min.
The area
The counties it named.
The facts
- Issued
- Jun 11, 1991, 9:29 PM EDT (01:29 UTC)
- Expired
- Jun 11, 1991, 10:15 PM EDT
- In force
- 46 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
Counties Bucks County, PA, Montgomery County, PA
The nearest sounding before it
Atlantic City In, NJ (KACY), launched 00:00Z, 1.5 hours before the alert went out and 111 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
- 130 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 1803 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 119 m²/s²
- 0-3 km storm-relative helicity
- 122 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KPHL 120130 SVRPHL PAC017-091-120215- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PHILADELPHIA PA 929 PM EDT TUE JUN 11 1991 THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1015 PM EDT FOR PEOPLE IN THE FOLLOWING LOCATIONS... IN SOUTHEAST PENNSYLVANIA ...BUCKS COUNTY...MONTGOMERY COUNTY AT 925 PM EDT WEATHER SERVICE RADAR INDICATED POSSIBLE SEVERE THUNDERSTORMS MOVING INTO BUCKS AND MONTGOMERY COUNTIES. THE THUNDERSTORMS WERE MOVING EAST AT 35 MPH. THESE ARE DANGEROUS STORMS. IF YOU ARE IN THE WARNED AREA...PREPARE FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN AND DEADLY LIqGHTNING. SHOULD THE STORMS APPROACH YOU...SEEK IMMEDIATE SHELTER INDOORS...BUT DO NOT STAND NEAR WINDOWS. MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED. DCY
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, Jun 11, 6:21 PM EDT, 3 hours 8 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHILADELPHIA PA 621 PM EDT JUN 6 1991E NATIONAL WEATHER SERVICE RADAR SHOWED SHOWERS AND A THUNDERSTORM THRU NORTHERN CHESTER COUNTY TO CENTRAL MONTGOMERY COUNTY AND WESTERN BUCKS COUNTY AT 620 PM EDT. THIS AREA IS MOVING EAST AT 30 MPH AND IT WILL MOVE INTO MERCER COUNTY IN ABOUT ONE HOUR. DANGEROUS LIGHTNING...GUSTY WINDS AND SOME SMALL HAIL MAY POSSIBLY ACCOMPANY THE THUNDERSTORM. KWH
Special weather statement, Jun 11, 7:05 PM EDT, 2 hours 24 minutes before
PAZ012-NJZ002 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHILADELPHIA PA 705 PM EDT JUN 6 1991E NATIONAL WEATHER SERVICE RADAR SHOWED SHOWERS AND THUNDERSTORMS FROM NORTHERN MERCER COUNTY THROUGH LOWER BUCKS COUNTY AND SOUTHERN MONTGOMERY COUNTY TO NORTHERN CHESTER COUNTY AT 7 PM EDT. THIS LINE WAS MOVING EAST AT 35 MPH. DANGEROUS LIGHTNING...GUSTY WINDS AND SOME SMALL HAIL MAY POSSIBLY ACCOMPANY THE THUNDERSTORMS. KWH
Special weather statement, Jun 11, 7:21 PM EDT, 2 hours 8 minutes before
PAZ011-016- 120100 - SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ALLENTOWN PA 720 PM EDT TUE JUN 11 1991 ...THUNDERSTORMS MOVING INTO SCHUYLKILL COUNTY... AT 720PM RADAR INDICATED A LINE OF THUNDERSTORMS EXTENDING FROM NEAR WILKES-BARRE SOUTHWEST THROUGH THE HAZELTON AREA AND INTO NORTHERN SCHUYLKILL COUNTY. A RATHER HEAVY THUNDERSTORM WAS NOTED SOUTHWEST OF ASHLAND IN NORTHWESTERN SCHUYLKILL COUNTY. MOVEMENT WAS TOWARD THE EAST AT AROUND 35 MPH. THESE THUNDERSTORMS CONTAIN GUSTY WINDS...HEAVY DOWNPOURS AND FREQUENT AND DANGEROUS LIGHTNING. PERSONS IN SCHUYLKILL AND CARBON COUNTIES SHOULD BE ALERT TO THESE THUNDERSTORMS AS THEY MOVE THROUGH THE AREA OVER THE NEXT HOUR OR SO. LOEPER
Special weather statement, Jun 11, 7:58 PM EDT, 1 hour 31 minutes before
PAZ012-NJZ002 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHILADELPHIA PA 800 PM EDT JUN 11 1991 NATIONAL WEATHER SERVICE RADAR SHOWED SHOWERS AND THUNDERSTORMS FROM SOUTHERN MERCER COUNTY THROUGH @LOWER BUCKS COUNTY TO SOUTHERN MONTGOMERY COUNTY AT 8 PM EDT. THIS LINE WAS MOVING EAST AT 35 MPH. DANGEROUS LIGHTNING...GUSTY WINDS AND SOME SMALL HAIL MAY ACCOMPANY THE THUNDERSTORMS. KWH
Special weather statement, Jun 11, 8:43 PM EDT, 46 minutes before
PAZ011-016-120200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ALLENTOWN PA 840 PM EDT TUE JUN 11 1991 ...SHOWERS AND THUNDERSTORMS APPROACHING THE LEHIGH VALLEY... AT 840PM RADAR INDICATED A BROKEN LINE OF SHOWERS AND THUNDERSTORMS EXTENDING FROM NEAR WILKES-BARRE SOUTH INTO CARBON COUNTY THEN SOUTH- WEST THROUGH BERKS COUNTY TO NEAR HARRISBURG. THIS LINE IS MOVING TOWARD THE EAST AND SOUTHEAST AT AROUND 30 MPH. THE HEAVIEST ACTIVITY WAS JUST TO THE NORTH OF READING IN BERKS COUNTY. THESE THUNDERSTORMS CONTAIN GUSTY WINDS...HEAVY DOWNPOURS AND FREQUENT AND DANGEROUS LIGHTNING. PERSONS IN LEHIGH VALLEY AREA AS WELL AS SOUTHERN BERKS COUNTY SHOULD BE ALERT TO THESE THUNDERSTORMS AS THEY MOVE THROUGH THE AREA BETWEEN 9PM AND MIDNIGHT. LOEPER
Special weather statement, Jun 11, 9:01 PM EDT, 28 minutes before
PAZ012-NJZ002 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHILADELPHIA PA 900 PM EDT JUN 11 1991 ...SHOWERS AND THUNDERSTORMS HEADED INTO SOUTHEASTERN PENNSYLVANIA... AT 845 PM EDT WEATHER SERVICE RADAR SHOWED A LINE OF SHOWERS AND THUNDERSTORMS EXTENDING THROUGH READING AND LANCASTER PENNSYLVANIA TO WEST OF BALTIMORE MARYLAND. THE STRONGEST THUNDERSTORM WAS NEAR READING IN CENTRAL BERKS COUNTY. THE SHOWERS AND THUNDERSTORMS WERE MOVING EAST AT 35 MPH AND WILL BE HEADED INTO BUCKS...MONTGOMERY AND CHESTER COUNTIES BY 930 PM EDT. DANGEROUS LIGHTNING...STRONG GUSTY WINDS...HEAVY DOWNPOURS AND POSSIBLY HAIL WILL ACCOMPANY THESE THUNDERSTORMS. IF THREATENING WEATHER APPROACHES YOUCR LOCATION...SEEK SHELTER INDOORS. STAY TUNED TO NOAA WEATHER RADIO FOR ADDITIONAL STATEMENTS AND POSSIBLE WARNINGS. YOUNG
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.