Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 21, NWS State College, PA

May 29, 1991Clinton County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at May 29, 1991, 4:19 PM EDT for Clinton County, Pennsylvania. It was in force for 56 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 29, 1991, 4:19 PM EDT (20:19 UTC)
Expired
May 29, 1991, 5:15 PM EDT
In force
56 min
Issued by
NWS State College, PA
Area
Whole counties

County Clinton County, PA

What was reported inside it

TimeReportWhereRemark
May 29, 4:26 PM EDTThunderstorm Wind 0Clinton, PA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.3 hours before the alert went out and 208 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, Buffalo Intl Airport, NY at 12:00Z on 1991-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 65 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 1991-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 186 square meters per square second.193958Sfc1 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
65 J/kg
Mixed-layer CIN
-205 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
186 m²/s²
0-3 km storm-relative helicity
216 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 KIPT 292019
SVRIPT
PAC035-292115-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
419 PM EDT WED MAY 29 1991
 
THE NATIONAL WEATHER SERVICE IN WILLIAMSPORT HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  515 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTH CENTRAL PENNSYLVANIA
 
   ...CLINTON COUNTY
 
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTsIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
PMG/TG
NNNN

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 29, 2:24 PM EDT, 1 hour 55 minutes before
PAZ007-008-014-292030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
224 PM EDT WED MAY 29 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 700 PM EDT FOR PORTIONS
OF NORTHCENTRAL PENNSYLVANIA...

THE NATIONAL WEATHER SERVICED HAS ISSUED A SEVERE THUNDERSTORM WATCH
EFFECTIVE UNTIL 700 PM EDT FOR PARTS OF NORTHCENTRAL PENNSYLVANIA. THIINCLUDES PORTIONS OF CLINTON...LYCOMING...BRADFORD AND TIOGA COUNTIES.

AT 215 PM EDT NATIONAL WEATHER SERVICE RADAR WAS SHOWING VERY STRONG
THUNDERSTORMS OVER NORHERN CLINTON AND LYCOMING COUNTIES. THE
STRONGEST THUNDERSTORMS WERE ALONG THE NORTHCENTRAL CLINTON-TIOGA
COUNTIES BORDER AND NEAR CEDAR RUN IN NORTHERN LYCOMING COUNTY. THE
THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AT 40 MPH.

THESE THUNDERSTORMS WILL CARRY DANGEROUS LIGHTNING...HEAVY
RAIN...GUSTY WINDS AND POSSIBLE HAIL WITH THEM. ANYONE THAT IS IN
THE PATH OF THESE STORMS OR OBSERVES THREATENING WEATHER SHOULD TAKE
SHELTER.

PMG/TG

NNNN
Special weather statement, May 29, 2:30 PM EDT, 1 hour 49 minutes before
PAZ007-008-014-292030-

SPECIAL WEATHER STATEMENT...CORRECTION...
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
224 PM EDT WED MAY 29 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 700 PM EDT FOR PORTIONS
OF NORTHCENTRAL PENNSYLVANIA...

THE NATIONAL WEATHER SERVICED HAS ISSUED A SEVERE THUNDERSTORM WATCH
EFFECTIVE UNTIL 700 PM EDT FOR PARTS OF NORTHCENTRAL PENNSYLVANIA.
THIS INCLUDES PORTIONS OF CLINTON...LYCOMING...BRADFORD AND TIOGA
COUNTIES.

AT 215 PM EDT NATIONAL WEATHER SERVICE RADAR WAS SHOWING VERY STRONG
THUNDERSTORMS OVER NORHERN CLINTON AND LYCOMING COUNTIES. THE
STRONGEST THUNDERSTORMS WERE ALONG THE NORTHCENTRAL CLINTON-TIOGA
COUNTIES BORDER AND NEAR CEDAR RUN IN NORTHERN LYCOMING COUNTY. THE
THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AT 40 MPH.

THESE THUNDERSTORMS WILL CARRY DANGEROUS LIGHTNING...HEAVY
RAIN...GUSTY WINDS AND POSSIBLE HAIL WITH THEM. ANYONE THAT IS IN
THE PATH OF THESE STORMS OR OBSERVES THREATENING WEATHER SHOULD TAKE
SHELTER.

PMG/TG

NNNN
Special weather statement, May 29, 2:45 PM EDT, 1 hour 34 minutes before
PAZ004-006-007-013-014-291945-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
235 PM EDT    WED  MAY 29 1991

...THUNDERSTORMS WERE MOVING THROUGH PORTIONS OF WESTERN AND NORTHERN
   PENNSYLVANIA...

AT 230 PM RADAR SHOWED SCATTERED THUNDERSTORMS FROM NEAR PITTSBURGH...
NORTHEAST THO NORTH OF WILLIAMSPORT. OTHER THUNDERSTORMS WERE OVER THE
LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS IN SOUTHERN PENNSYLVANIA.
THE STORMS COULD PRODUCE HEAVY RAIN...HAIL...STRONG GUSTY WINDS AND
DANGEROUS LIGHTNING. THE STORMS TO THE SOUTH ALSO REACHED SOUTH INTO
WESTERN MARYLAND WHERE SOME MARBLE SIZE HAIL WAS REPORTED EARLIER.
THESE STORMS WERE MOVING MAINLY EAST TO SOUTHEAST AROUND 25 MPH.

PERSONS IN THESE AREAS AND ADJACENT AREAS TO THE EAST SOUTHEAST SHOULD
BE ALERT FOR THE PASSAGE OF THE STORMS. IF THREATENING WEATHER APPROACHES
GO TO A SAFE PLACE.

WSO HAR JORDAN
Special weather statement, May 29, 3:31 PM EDT, 48 minutes before
PAZ006-007-008-013-014-292015-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
320 PM EDT    WED  MAY 29 1991

...THUNDERSTORMS CONTINUE ACROSS PORTIONS OF WESTERN AND CENTRAL
PENNSYLVANIA...

AT 320 PM RADAR SHOWED SCATTERED THUNDERSTORMS FROM NEAR PITTSBURGH...
NORTHEAST TO SOUTH AND EAST OF WILLIAMSPORT. SOME OF THESE THUNDERSTORMS
WERE PRODUCING HEAVY RAIN...STRONG GUSTY WINDS...DANGEROUS LIGHTNING AND
POSSIBLY SMALL HAIL. WE HAVE RECEIVED A REPORT THAT HEAVY RAIN AND STRONG
WINDS WERE OCCURRING IN NORTHERN UNION AND NORTHERN NORTHUMBERLAND COUNTIES.
OTHER THUNDERSTORMS WERE OVER PORTIONS OF THE SOUTH CENTRAL MOUNTAINS...
MAINLY IN FULTON AND FRANKLIN COUNTIES.

THESE THUNDERSTORMS WERE MOVING MAINLY TO THE EAST SOUTHEAST AROUND 25
MPH.
.
PERSONS IN THESE AREAS AND ADJACENT AREAS TO THE EAST AND SOUTHEAST
SHOULD BE ALERT FOR THE PASSAGE OF THESE STORMS. IF THREATENING
APPROACHES GO TO A SAFE PLACE.

WSO HAR JORDAN
Special weather statement, May 29, 3:50 PM EDT, 29 minutes before
PAZ006-008-009-013-292030-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA
348 PM EDT WED MAY 29 1991

...THUNDERSTORMS CONTINUE TO MOVE THROUGH PARTS OF CENTRAL AND
   WESTERN PENNSYLVANIA...

AT 330 PM THE NATIONAL WEATHER SERVICE RADAR IN HARRISBURG SHOWED STRONG
THUNDERSTORMS MOVING THROUGH CENTRAL PENNSYLVANIA. ONE OF THE STRONG
STORMS WAS IN SOUTHWEST FULTON COUNTY ABOUT 15 MILES WEST OF MERCERSBURG.

THE RADAR SHOWED ANOTHER STRONG STORM IN SOUTHERN CENTRE COUNTY ABOUT 15
MILES SOUTHEAST OF STATE COLLEGE...AND ANOTHER STRONG STORM IN SOUTHERN
CLINTON COUNTY ABOUT 20 MILES SOUTHWEST OF WILLIAMSPORT.

THE STORMS WERE MOVING TO THE SOUTHEAST AT ABOUT 25 MILES AN HOUR. AT THIS
RATE THE STORM IN FULTON COUNTY WILL BE MOVING INTO MARYLAND BY ABOUT 415
PM. THE STORM IN SOUTHERN CENTRE COUNTY WILL BE ABOUT 10 MILES EAST OF
HUNTINGDON BY 445 PM AND THE STORM IN CLINTON COUNTY WILL PUSH ACROSS
UNION COUNTY AND BE ABOUT 5 MILES EAST OF SELINSGROVE BY 445 PM.
.
SOME OF THE STORMS HAVE ALREADY PRODUCED SMALL HAIL...GUSTY WINDS
AND HEAVY DOWNPOURS. IF YOU SEE THREATENING WEATHER APPROACH YOU
SHOULD SEEK SHELTER IMMEDIATELY.

WSO HAR RBH

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 2:40 PM EDTSevere Thunderstorm WarningCTPLycoming65 min
May 29, 3:17 PM EDTSevere Thunderstorm WarningCTPClinton43 min
May 29, 4:39 PM EDTSevere Thunderstorm WarningCTPJuniata, Perry, Snyder66 min
May 29, 5:14 PM EDTSevere Thunderstorm WarningCTPBerks31 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.