Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1993
Severe Thunderstorm Warning 20, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 21, 1993, 5:41 PM EDT for Montgomery County, Pennsylvania. It was in force for 64 min.
The area
The counties it named.
The facts
- Issued
- Jun 21, 1993, 5:41 PM EDT (21:41 UTC)
- Expired
- Jun 21, 1993, 6:45 PM EDT
- In force
- 64 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
County Montgomery County, PA
The nearest sounding before it
Atlantic City In, NJ (KACY), launched 12:00Z, 9.7 hours before the alert went out and 112 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
- 697 J/kg
- Mixed-layer CIN
- -78 J/kg
- Mixed-layer LCL
- 959 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 71 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.7
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KPHL 212143 RRA SVRPHL PAC091-212245- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PHILADELPHIA PA 541 PM EDT MON JUN 21 1993 THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 645 PM EDT FOR PEOPLE IN THE FOLLOWING LOCATION... IN SOUTHEAST PENNSYLVANIA ...WESTERN MONTGOMERY COUNTY WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM MOVING THROUGH POTTSTOWN. THIS STORM WAS HEADED EAST NORTHEAST AROUND 35 MILES AN HOUR...AND WILL CONTINUE TO AFFECT MONTGOMERY COUNTY THROUGH 645 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. THE HEAVY RAINS WITH THIS THUNDERSTORM MAY CAUSE RAPID FLOODING OF STREAMS AND UNDERPASSES. DO NOT DRIVE YOUR CAR INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER MAY BE DEEPER THAN YOU THINK. IF CAUGHT IN RISING WATERS...ABANDON YOUR CAR QUICKLY AND MOVE TO HIGHER GROUND. 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 21, 5:15 PM EDT, 26 minutes before
PAZ011-016-210000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ALLENTOWN PA 515 PM EDT MON JUN 21 1993 ...SEVERE THUNDERSTORM WATCH IN EFFECT FOR EAST CENTRAL PENNSYLVANIA... A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MUCH OF EASTERN PENNSYLVANIA INCLUDING THE COUNTIES OF BERKS...LEHIGH AND NORTHAMPTON UNTIL 9PM THIS EVENING.AT 510PM RADAR INDICATED A LINE OF THUNDERSTORMS EXTENDING FROM NEAR STROUDSBURG SOUTHWEST THROUGH THE LEHIGH VALLEY TO SOUTHERN BERKS COUNTY. SOME OF THESES THUNDERSTORMS HAD EXHIBITED SEVERE CHARACTERISTICS AS THEY MOVED FROM BERKS INTO LEHIGH COUNTY. THESE STORMS ARE PRODUCING VERY HEAVY RAINFALL AT THIS TIME AS THEY CONTINUE TO MOVE EAST AND TOWARD NEW JERSEY. 1.1" FELL IN LOWER MAGUNGIE TWSP. SOUTH OF ALLENTOWN IN A 30 MINUTE PERIOD. THE THUNDERSTORMS SHOULD BE OUT OF THE AREA BY 6PM THIS EVENING. LOEPER
Special weather statement, Jun 21, 5:17 PM EDT, 24 minutes before
DEZ003-220015- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILMINGTON DE 517 PM EDT MON JUN 21 1993 ...LINE OF THUNDERSTORMS MOVING TOWARD NEW CASTLE COUNTY... AT 516 PM EDT THIS AFTERNOON WEATHER SERVICE RADAR SHOWED A LINE OF THUNDERSTORMS STRETCHING FROM JUST EAST OF LANCASTER PENNSYLVANIA SOUTHWESTWARD TO AROUND 15 MILES WEST OF BALTIMORE MARYLAND. THESE STORMS WERE MOVING TO THE EAST NORTHEAST AT NEAR 35 MPH. THESE STORMS WILL BEGIN TO EFFECT PORTIONS OF NEW CASLTE COUNTY JUST AFTER 600 PM EDT THIS EVENING. THE STRONGEST THUNDERSTORM WAS LOCATED ABOUT 15 MILES NORTH OF BALTIMORE MARYLAND OR ABOUT 40 MILES SOUTHWEST OF WILMINGTON. THESE STORMS WILL PRODUCE VERY HEAVY RAIN...STRONG GUSTY WINDS AND FREQUENT DEADLY LIGHTNING. PERSONS ACROSS NORTHERN DELAWARE SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS. IF THREATENING WEATHER APPROACHES SEEK SAFE SHELTER IMMEDIATELY INDOORS...STAY AWAY FROM WINDOWS AND AVOID USING ELECTRICAL APPLIANCES INCLUDING THE TELEPHONE. VAUGHAN
Special weather statement, Jun 21, 5:19 PM EDT, 22 minutes before
PAZ011-016-210000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE ALLENTOWN PA 515 PM EDT MON JUN 21 1993 ...SEVERE THUNDERSTORM WATCH IN EFFECT FOR EAST CENTRAL PENNSYLVANIA... A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MUCH OF EASTERN PENNSYLVANIA INCLUDING THE COUNTIES OF BERKS...LEHIGH AND NORTHAMPTON UNTIL 9PM THIS EVENING.AT 510PM RADAR INDICATED A LINE OF THUNDERSTORMS EXTENDING FROM NEAR STROUDSBURG SOUTHWEST THROUGH THE LEHIGH VALLEY TO SOUTHERN BERKS COUNTY. SOME OF THESES THUNDERSTORMS HAD EXHIBITED SEVERE CHARACTERISTICS AS THEY MOVED FROM BERKS INTO LEHIGH COUNTY. THESE STORMS ARE PRODUCING VERY HEAVY RAINFALL AT THIS TIME AS THEY CONTINUE TO MOVE EAST AND TOWARD NEW JERSEY. 1.1" FELL IN LOWER MAGUNGIE TWSP. SOUTH OF ALLENTOWN IN A 30 MINUTE PERIOD. THE THUNDERSTORMS SHOULD BE OUT OF THE AREA BY 6PM THIS EVENING. LOEPER
Special weather statement, Jun 21, 5:19 PM EDT, 22 minutes before
DEZ003-220015- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILMINGTON DE 517 PM EDT MON JUN 21 1993 ...LINE OF THUNDERSTORMS MOVING TOWARD NEW CASTLE COUNTY... AT 516 PM EDT THIS AFTERNOON WEATHER SERVICE RADAR SHOWED A LINE OF THUNDERSTORMS STRETCHING FROM JUST EAST OF LANCASTER PENNSYLVANIA SOUTHWESTWARD TO AROUND 15 MILES WEST OF BALTIMORE MARYLAND. THESE STORMS WERE MOVING TO THE EAST NORTHEAST AT NEAR 35 MPH. THESE STORMS WILL BEGIN TO EFFECT PORTIONS OF NEW CASLTE COUNTY JUST AFTER 600 PM EDT THIS EVENING. THE STRONGEST THUNDERSTORM WAS LOCATED ABOUT 15 MILES NORTH OF BALTIMORE MARYLAND OR ABOUT 40 MILES SOUTHWEST OF WILMINGTON. THESE STORMS WILL PRODUCE VERY HEAVY RAIN...STRONG GUSTY WINDS AND FREQUENT DEADLY LIGHTNING. PERSONS ACROSS NORTHERN DELAWARE SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS. IF THREATENING WEATHER APPROACHES SEEK SAFE SHELTER IMMEDIATELY INDOORS...STAY AWAY FROM WINDOWS AND AVOID USING ELECTRICAL APPLIANCES INCLUDING THE TELEPHONE. VAUGHAN
Special weather statement, Jun 21, 5:28 PM EDT, 13 minutes before
NJZ003-004-006-212245 SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE ATLANTIC CITY NJ 528 PM EDT MON JUN 21 1993 ...SEVERE THUNDERSTORM WATCH UNTIL 10 PM FOR OCEAN AND BURLINGTON COUNTIES AND THE ADJACENT COASTAL WATERS... ...STRONG STORMS MOVE ACROSS EASTERN PENNSYLVANIA... AT 528 PM...ATLANTIC CITY WEATHER RADAR SHOWED A LINE OF SHOWERS AND STRONG THUNDERSTORMS STRETCHING FROM SUSSEX COUNTY NEW JERSEY THROUGH ALLENTOWN TO LANCASTER TO BALTIMORE COUNTY MARYLAND. THE HEAVIEST RAIN WAS INDICATED NEAR EASTON AND POTTSTOWN PENNSYLVANIA. MOVEMENT WAS TO THE EAST AROUND 30 MILES AN HOUR. REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR THE DEVELOPMENT OF SEVERE THUNDERSTORMS. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL STATION FOR THE LATEST INFORMATION. GERAPETRITIS
Special weather statement, Jun 21, 5:38 PM EDT, 3 minutes before
NJZ003-004-006-212245 SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE ATLANTIC CITY NJ 528 PM EDT MON JUN 21 1993 ...SEVERE THUNDERSTORM WATCH UNTIL 10 PM FOR OCEAN AND BURLINGTON COUNTIES AND THE ADJACENT COASTAL WATERS... ...STRONG STORMS MOVE ACROSS EASTERN PENNSYLVANIA... AT 528 PM...ATLANTIC CITY WEATHER RADAR SHOWED A LINE OF SHOWERS AND STRONG THUNDERSTORMS STRETCHING FROM SUSSEX COUNTY NEW JERSEY THROUGH ALLENTOWN TO LANCASTER TO BALTIMORE COUNTY MARYLAND. THE HEAVIEST RAIN WAS INDICATED NEAR EASTON AND POTTSTOWN PENNSYLVANIA. MOVEMENT WAS TO THE EAST AROUND 30 MILES AN HOUR. REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR THE DEVELOPMENT OF SEVERE THUNDERSTORMS. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL STATION FOR THE LATEST INFORMATION. GERAPETRITIS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 8:08 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 52 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 1993Every 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.