Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 90, NWS Philadelphia/Mount Holly

August 13, 1994Berks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 1994, 3:59 PM EDT for Berks County, Montgomery County, Pennsylvania. It was in force for 46 min.

The area

The counties it named.

The facts

Issued
Aug 13, 1994, 3:59 PM EDT (19:59 UTC)
Expired
Aug 13, 1994, 4:45 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Berks County, PA, Montgomery County, PA

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 8.0 hours before the alert went out and 137 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 1994-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1816 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 1994-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.1939Sfc1 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
1816 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
906 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 132006 RRA
SVRPHL
PAC011-091-132045-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
359 PM EDT SAT AUG 13 1994
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  445 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN EAST CENTRAL PENNSYLVANIA
 
   ...SOUTHEASTERN BERKS COUNTY
 
IN SOUTHEAST PENNSYLVANIA
 
   ...NORTHWESTERN MONTGOMERY COUNTY
 
AT 400 PM RADAR SHOWED A STRONG THUNDERSTORM OVER DOUGLASS TOWNSHIP
SOUTHEAST BERKS COUNTY. IT WAS MOVING EAST NORTHEAST 25 TO 30 MPH. THE
STORM WILL MOVE INTO MONTGOMERY COUNTY WITHIN THE NEXT 20 MINUTES.
 
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR A LARGE PART OF
EASTERN PENNSYLVANIA UNTIL 8 PM EDT.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN THE WARNED AREA...PREPARE
FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN AND DEADLY
LIGHTNING.  SHOULD THE STORM APPROACH YOU...SEEK IMMEDIATE SHELTER
INDOORS...BUT DO NOT STAND NEAR WINDOWS.  MOBILE HOMES ARE MOST
VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED.

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 13, 2:42 PM EDT, 1 hour 17 minutes before
NJZ019>026-501-131945-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
240 PM EDT SAT AUG 13 1994

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR OCEAN, BURLINGTON,
ATLANTIC, CUMBERLAND, AND CAPE MAY COUNTIES, INCLUDING ADJACENT
COASTAL WATERS, UNTIL 800 PM...

AT 230 PM...THERE WERE NO THUNDERSTORMS WITHIN 100 MILES OF ATLANTIC
CITY.  HOWEVER, ANY THUNDERSTORM THAT DOES DEVELOP THIS AFTERNOON AND
EVENING HAS THE POTENTIAL TO PRODUCE DAMAGING WIND AND HAIL...SO BE
ON THE LOOKOUT.

FRANKLIN
Special weather statement, Aug 13, 2:42 PM EDT, 1 hour 17 minutes before
DEZ001-002-140045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON DE
242 PM EDT SAT AUG 13 1994

...SEVERE THUNDERSTORM WATCH FOR NORTHERN DELAWARE...

THE NATIONAL SEVERE STORMS FORECAST CENTER HAS ISSUED A SEVERE
THUNDERSTORM WATCH EFFECTIVE UNTIL 8 PM THIS EVENING FOR NORTHERN
DELAWARE TO INCLUDE NEW CASTLE AND KENT COUNTIES AND ADJACENT COASTAL
WATERS.

LARGE HAIL...DANGEROUS LIGHTNING AND DAMAGING THUNDERSTORM WINDS ARE
POSSIBLE IN THESE AREA.

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

LYLES

NNNN
Special weather statement, Aug 13, 2:55 PM EDT, 1 hour 4 minutes before
PAZ037>071-NJZ015>026-140000-

SPECIAL WEATHER STATEMENT - SEVERE THUNDERSTORM WATCH/HEAVY RAIN
NATIONAL WEATHER SERVICE PHILADELPHIA PA/MOUNT HOLLY NJ
255 PM EDT SAT AUG 13 1994

....SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 800 PM EDT...

THE NATIONAL SEVERE STORMS FORECAST CENTER IN KANSAS CITY HAS ISSUED A
SEVERE THUNDERSTORM WATCH EFFECTIVE UNTIL 800 PM EDT THIS SATURDAY
EVENING FOR MOST OF EASTERN PENNSYLVANIA AND ALL OF SOUTHERN NEW JERSEY.

THE ONLY EASTERN PENNSYLVANIA COUNTIES...EXCLUDED...FROM THE WATCH AREA
ARE...BRADFORD...CLINTON...LYCOMING...SULLIVAN AND TIOGA.

AT 245 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED A LARGE
AREA OF SHOWERS AND THUNDERSTORMS COVERING MUCH OF WESTERN AND NORTH
CENTRAL PENNSYLVANIA.  THE SOUTHERN EDGE OF THIS PRECIPITATION AREA
EXTENDED FROM NEAR PITTSBURGH NORTHEAST THROUGH SUSQUEHANNA COUNTY.
HEAVY RAIN HAS OCCURRED IN PARTS OF WESTERN PENNSYLVANIA WITH THIS AREA.
TRAINING OF THESE THUNDERSTORM MAY ALSO PRODUCE AROUND TWO /2.0/ INCHES
OF RAINFALL IN A SHORT PERIOD OF TIME IN PARTS OF EASTERN PENNSYLVANIA.
THE SPECIFIC REGIONS MOST PRONE TO HEAVY RAIN INCLUDE THE MIDDLE AND
UPPER SUSQUEHANNA VALLEY...PARTS OF THE LEHIGH VALLEY...NORTHEAST AND
POCONOS.

DOPPLER RADAR ALSO INDICATED THUNDERSTORM DEVELOPMENT NEAR HAGARSTOWN
MARYLAND AND WHEELING WEST VIRGINIA...SOUTH OF THE WIDESPREAD
PRECIPITATION AREA.  THESE THUNDERSTORMS...AS WELL AS OTHERS THAT MAY
DEVELOP IN THE HOT AND HUMID AIRMASS...MAY EFFECT THE WEATHER IN THE
REMAINDER OF THE WATCH AREA INCLUDING SOUTHERN PENNSYLVANIA AND SOUTHERN
NEW JERSEY LATER THIS AFTERNOON AND EVENING.

SEVERE THUNDERSTORMS PRODUCE LARGE DAMAGING HAIL 3/4 OF AN INCH OR
LARGER IN DIAMETER...DAMAGING THUNDERSTORMS WINDS OF 58 MPH OR GREATER
AND DANGEROUS CLOUD TO GROUND LIGHTING.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE WEATHER IN AND CLOSE TO THE WATCH AREA.  IF YOU LIVE IN OR
NEAR THE AREA...BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND
LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS.

ALSO...THUNDERSTORM ACTIVITY IN THE PRESENT AIRMASS HAS THE POTENTIAL TO
PRODUCE COPIOUS AMOUNTS OF RAINFALL IN A SHORT PERIOD OF TIME.  AS A
RESULT...THE POTENTIAL EXISTS FOR FLOODING IN URBAN AND POOR DRAINAGE
LOCATIONS.  RAPID RISES ON STREAMS AND CREEKS SHOULD ALSO BE MONITORED.

DCY
Special weather statement, Aug 13, 2:59 PM EDT, 1 hour before
PAZ037>071-NJZ015>026-140000-

SPECIAL WEATHER STATEMENT - SEVERE THUNDERSTORM WATCH/HEAVY RAIN
NATIONAL WEATHER SERVICE PHILADELPHIA PA/MOUNT HOLLY NJ
255 PM EDT SAT AUG 13 1994

....SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 800 PM EDT...

THE NATIONAL SEVERE STORMS FORECAST CENTER IN KANSAS CITY HAS ISSUED A
SEVERE THUNDERSTORM WATCH EFFECTIVE UNTIL 800 PM EDT THIS SATURDAY
EVENING FOR MOST OF EASTERN PENNSYLVANIA AND ALL OF SOUTHERN NEW JERSEY.

THE ONLY EASTERN PENNSYLVANIA COUNTIES...EXCLUDED...FROM THE WATCH AREA
ARE...BRADFORD...CLINTON...LYCOMING...SULLIVAN AND TIOGA.

AT 245 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED A LARGE
AREA OF SHOWERS AND THUNDERSTORMS COVERING MUCH OF WESTERN AND NORTH
CENTRAL PENNSYLVANIA.  THE SOUTHERN EDGE OF THIS PRECIPITATION AREA
EXTENDED FROM NEAR PITTSBURGH NORTHEAST THROUGH SUSQUEHANNA COUNTY.
HEAVY RAIN HAS OCCURRED IN PARTS OF WESTERN PENNSYLVANIA WITH THIS AREA.
TRAINING OF THESE THUNDERSTORM MAY ALSO PRODUCE AROUND TWO /2.0/ INCHES
OF RAINFALL IN A SHORT PERIOD OF TIME IN PARTS OF EASTERN PENNSYLVANIA.
THE SPECIFIC REGIONS MOST PRONE TO HEAVY RAIN INCLUDE THE MIDDLE AND
UPPER SUSQUEHANNA VALLEY...PARTS OF THE LEHIGH VALLEY...NORTHEAST AND
POCONOS.

DOPPLER RADAR ALSO INDICATED THUNDERSTORM DEVELOPMENT NEAR HAGARSTOWN
MARYLAND AND WHEELING WEST VIRGINIA...SOUTH OF THE WIDESPREAD
PRECIPITATION AREA.  THESE THUNDERSTORMS...AS WELL AS OTHERS THAT MAY
DEVELOP IN THE HOT AND HUMID AIRMASS...MAY EFFECT THE WEATHER IN THE
REMAINDER OF THE WATCH AREA INCLUDING SOUTHERN PENNSYLVANIA AND SOUTHERN
NEW JERSEY LATER THIS AFTERNOON AND EVENING.

SEVERE THUNDERSTORMS PRODUCE LARGE DAMAGING HAIL 3/4 OF AN INCH OR
LARGER IN DIAMETER...DAMAGING THUNDERSTORMS WINDS OF 58 MPH OR GREATER
AND DANGEROUS CLOUD TO GROUND LIGHTING.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE WEATHER IN AND CLOSE TO THE WATCH AREA.  IF YOU LIVE IN OR
NEAR THE AREA...BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND
LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS.

ALSO...THUNDERSTORM ACTIVITY IN THE PRESENT AIRMASS HAS THE POTENTIAL TO
PRODUCE COPIOUS AMOUNTS OF RAINFALL IN A SHORT PERIOD OF TIME.  AS A
RESULT...THE POTENTIAL EXISTS FOR FLOODING IN URBAN AND POOR DRAINAGE
LOCATIONS.  RAPID RISES ON STREAMS AND CREEKS SHOULD ALSO BE MONITORED.

DCY
Special weather statement, Aug 13, 3:45 PM EDT, 14 minutes before
NJZ019>026-501-132045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
345 PM EDT SAT AUG 13 1994

...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM...

AT 330 PM...THERE WERE NO THUNDERSTORMS ACROSS SOUTHERN NEW JERSEY AND
THE ADJACENT COASTAL WATERS.

MEANWHILE...THUNDERSTORMS, SOME WITH VERY HEAVY RAIN, WERE SCATTERED
ACROSS MARYLAND AND SOUTHERN PENNSYLVANIA.  THEY WILL REACH SOUTHEASTERN
NEW JERSEY AFTER 600 PM.

KEEP IN MIND THAT ANY THUNDERSTORM THIS AFTERNOON AND EVENING HAS THE
POTENTIAL TO PRODUCE DAMAGING WIND AND HAIL...SO BE ON THE LOOKOUT.

FRANKLIN
Special weather statement, Aug 13, 3:47 PM EDT, 12 minutes before
NJZ019>026-501-132045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTIC CITY NJ
345 PM EDT SAT AUG 13 1994

...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM...

AT 330 PM...THERE WERE NO THUNDERSTORMS ACROSS SOUTHERN NEW JERSEY AND
THE ADJACENT COASTAL WATERS.

MEANWHILE...THUNDERSTORMS, SOME WITH VERY HEAVY RAIN, WERE SCATTERED
ACROSS MARYLAND AND SOUTHERN PENNSYLVANIA.  THEY WILL REACH SOUTHEASTERN
NEW JERSEY AFTER 600 RPM.

KEEP IN MIND THAT ANY THUNDERSTORM THIS AFTERNOON AND EVENING HAS THE
POTENTIAL TO PRODUCE DAMAGING WIND AND HAIL...SO BE ON THE LOOKOUT.

FRANKLIN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 4:35 PM EDTSevere Thunderstorm WarningPHIBucks40 min
Aug 13, 5:21 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery54 min
Aug 13, 6:22 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia33 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1994Every severe thunderstorm warning in 1994

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.