Alert archive / Pennsylvania / Tornado Warnings in 1991

Tornado Warning 1, NWS State College, PA

July 7, 1991York County, Pennsylvania

NWS State College, PA issued this tornado warning at Jul 7, 1991, 1:22 PM EDT for York County, Pennsylvania. It was in force for 23 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
Jul 7, 1991, 1:22 PM EDT (17:22 UTC)
Expired
Jul 7, 1991, 1:45 PM EDT
In force
23 min
Issued by
NWS State College, PA
Area
Whole counties

County York County, PA

What was reported inside it

TimeReportWhereRemark
Jul 7, 1:50 PM EDTThunderstorm Wind 65York, 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.4 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 1991-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1279 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, Washington/Dulle, VA at 12:00Z on 1991-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 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
1279 J/kg
Mixed-layer CIN
-100 J/kg
Mixed-layer LCL
1270 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this tornado 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, Jul 7, 9:05 AM EDT, 4 hours 17 minutes before
PAZ007-008-014-071400

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
905 AM EDT SUN JUL 7 1991

...THUNDERSTORMS CONTINUING TO MOVE ACROSS NORTHCENTRAL
PENNSYLVANIA...

AT 900 AM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A FAIRLY
SOLID AREA OF SHOWERS AND THUNDERSTORMS COVERING TIOGA AND BRADFORD
COUNTIES. EXTENDING OUT OF THAT SOLID AREA WAS A LINE OF SHOWERS AND
STRONGER THUNDERSTORMS EXTENDING FROM TOWANDA IN BRADFORD COUNTY
THROUGH CENTRAL SULLIVAN COUNTY...SOUTHEAST LYCOMING COUNTY AND INTO
SOUTHEAST CENTRE COUNTY.

MOST OF THE THUNDERSTORM ACTIVITY WAS DECREASING IN INTENSITY WITH THE
STRONGEST THUNDERSTORM LOCATED IN SULLIVAN COUNTY JUST NORTH OF
LAPORTE.

THESE STORMS WERE PART OF A LARGE AREA OF SHOWERS AND THUNDERSTORMS
THAT STRETCHED FROM CENTRAL NEW YORK INTO NORTHWEST AND NORTHCENTRAL
PENNSYLVANIA.  MOVEMENT OF THE THUNDERSTORMS WAS TOWARD THE EAST AT 40
MPH.

HEAVY DOWNPOURS...GUSTY WINDS...AND LIGHTNING WILL ACCOMPANY THESE
THUNDERSTORMS AS THEY CONTINUE TO MOVE ACROSS NORTHCENTRAL
PENNSYLVANIA THIS SUNDAY MORNING.

REMEMBER...ANY THUNDERSTORM CAN BE DANGEROUS.  TO PROTECT YOURSELF
FROM THE DANGERS OF LIGHTNING...REMAIN INDOORS AND DO NOT USE
ELECTRICAL APPLIANCES.  HEAVY RAINS CAN FLOOD ROADS QUICKLY...SO DO
NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROADWAY.

PMG
Special weather statement, Jul 7, 9:19 AM EDT, 4 hours 3 minutes before
PAZ008-013-014-071430-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA
915 AM EDT SUN JUL 7 1991

...THUNDERSTORMS OVER THE CENTRAL MOUNTAINS AND MIDDLE SUSQUEHANNA VALLEY...

AT 910 AM WEATHER SERVICE RADAR IN HARRISBURG SHOWED AN AREA OF THUNDERSTORMS
SOME WITH VERY HEAVY RAIN...OVER CENTRE AND EAST UNION COUNTIES.  DURING THE
NEXT HOUR THE STORMS WILL MOVE INTO THE COUNTIES OF MIFFLIN...SYNDER...AND
NORTHUMBERLAND AROUND 1000 AM.

THESE THUNDERSTORMS MAY PRODUCE GUSTY WINDS...HAIL...DANGEROUS LIGHTNING...
AS WELL AS LOCALLY HEAVY DOWNPOURS. IF THREATENING WEATHER APPROACHES...MOVE
INDOORS AND STAY AWAY FROM WINDOWS.

LISTEN TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV FOR POSSIBLE WATCHES
OR WARNINGS.

WSO HAR CRUZ
Special weather statement, Jul 7, 10:53 AM EDT, 2 hours 29 minutes before
PAZ008-009-013-014-072100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA
1055 AM EDT SUN JUL 7 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR MUCH OF CENTRAL AND SOUTHERN
PENNSYLVANIA UNTIL 500 PM EDT...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR MUCH
OF CENTRAL AND SOUTHERN PENNSYLVANIA. THIS INCLUDES ADAMS...CENTRE...CUMBERLAND
...DAUPHIN...FRANKLIN...FULTON...HUNTINGDON...JUNIATA...MIFFLIN...MONTOUR...
NORTHUMBERLAND...PERRY...SYNDER...UNION...AND YORK COUNTIES.

THESE THUNDERSTORMS MAY PRODUCE GUSTY WINDS...HAIL...DANGEROUS LIGHTNING...
AS WELL AS LOCALLY HEAVY DOWNPOURS. IF THREATENING WEATHER APPROACHES...MOVE
INDOORS AND STAY AWAY FROM WINDOWS.

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

WSO HAR CRUZ
Special weather statement, Jul 7, 11:14 AM EDT, 2 hours 8 minutes before
PAZ007-008-014-071615

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
1114 AM EDT SUN JUL 07 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR PORTIONS OF NORTHCENTRAL
PENNSYLVANIA UNTIL 500 PM THIS EVENING...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR SOUTHERN CLINTON AND SOUTHERN LYCOMING COUNTIES UNTIL 500 PM EDT.
THIS INCLUDES THE CITIES OF WILLIAMSPORT AND LOCK HAVEN.

AT 1105 AM EDT NATIONAL WEATHER SERVICE RADAR SHOWED NUMEROUS SHOWERS
AND A FEW THUNDERSTORMS OVER SOUTHERN TIOGA AND BRADFORD COUNTIES...
WESTERN SULLIVAN COUNTY...ALMOST ALL OF LYCOMING AND CLINTON
COUNTIES...AND PORTIONS OF CENTRE AND CLEARFIELD COUNTIES. THE
STRONGEST THUNDERSTORMS WERE IN CENTRE AND CLEARFIELD COUNTIES. THESE
THUNDERSTORMS COULD CONTAIN STRONG GUSTY WINDS...DANGEROUS
LIGHTNING...HAIL AND LOCALLY HEAVY DOWNPOURS. THESE THUNDERSTORMS WERE
MOVING TO THE EAST AT 25 MPH.

PERSONS IN AND CLOSE TO THE WATCH AREA ARE ADVISED TO BE ALERT TO
LOCAL WEATHER CONDITIONS. IF THREATENING WEATHER APPROACHES...GO TO A
SAFE PLACE IMMEDIATELY AND IF INSIDE STAY AWAY FROM WINDOWS.

PMG/KJF
Special weather statement, Jul 7, 11:41 AM EDT, 1 hour 41 minutes before
PAZ008-009-013-014-072100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA
1130 AM EDT SUN JUL 7 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR MUCH OF CENTRAL AND SOUTHERN
PENNSYLVANIA UNTIL 500 PM EDT...

...STRONG THUNDERSTORMS OVER WESTERN AND SOUTHEASTERN PENNSYLVANIA...

AT 1130 AM WEATHER SERVICE RADAR IN HARRISBURG SHOWED A LINE OF STRONG
THUNDERSTORMS WITH HEAVY RAIN EXTENDING THROUGH NORTH ARMSTRONG...NORTH
INDIANA ...SOUTH CLEARFIELD...AND WEST CENTRE COUNTY. ANOTHER LINE OF STRONG
THUNDERSTORMS WITH HEAVY RAIN EXTENDED THROUGH NORTHAMPTON...EAST READING...
EAST LANCASTER...AND SOUTHEAST YORK COUNTIES.

THESE THUNDERSTORMS MAY BE ACCOMPANIED BY STRONG DAMAGING WINDS...LARGE HAIL
...TORRENTIAL DOWNPOURS...AND DANGEROUS LIGHTNING.

THE THUNDERSTORMS WERE MOVING EAST SOUTHEAST AT 40 MILES AN HOUR.

IF YOU SEE ANY SIGNS OF SEVERE WEATHER...GET INDOORS IMMEDIATELY. STAY
TUNED TO NOAA WEATHER RADIO...OR YOyUR LOCAL RADIO OR TELEVESION STATION
FOR ADDITIONAL STATEMENTS OR POSSIBLE WARNINGS.

WSO HAR CRUZ
Special weather statement, Jul 7, 12:15 PM EDT, 1 hour 7 minutes before
PAZ007-008-014-071715

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
1215 PM EDT SUN JUL 07 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR PORTIONS OF NORTHCENTRAL
PENNSYLVANIA UNTIL 500 PM THIS EVENING...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR CLINTON AND LYCOMING COUNTIES UNTIL 500 PM EDT. THIS INCLUDES THE
CITIES OF WILLIAMSPORT AND LOCK HAVEN.

AT 1200 PM EDT NATIONAL WEATHER SERVICE RADAR SHOWED A DIMINISHING
LINE OF SHOWERS AND A FEW THUNDERSTORMS STRETCHING INTO CENTRAL
PENNSYLVANIA.  AT THIS TIME RADAR SHOWED NO THUNDERSTORMS IN
NORTHCENTRAL PENNSYLVANIA.  STRONG STORMS CONTINUED TO STAY IN THE
SOUTHERN HALF OF THE STATE.  THE THUNDERSTORMS WERE MOVING EAST AT 30
MPH.

PERSONS IN AND CLOSE TO THE WATCH AREA ARE ADVISED TO BE ALERT TO
LOCAL WEATHER CONDITIONS. IF THREATENING WEATHER APPROACHES...GO TO A
SAFE PLACE IMMEDIATELY...PREFERABLY INDOORS AND AWAY FROM WINDOWSK.

PMG/KJF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 8:54 AM EDTSevere Thunderstorm WarningCTPCentre66 min
Jul 7, 10:38 AM EDTSevere Thunderstorm WarningCTPLehigh67 min
Jul 7, 12:06 PM EDTSevere Thunderstorm WarningCTPHuntingdon, Mifflin54 min
Jul 7, 12:44 PM EDTSevere Thunderstorm WarningCTPHuntingdon31 min
Jul 7, 12:56 PM EDTSevere Thunderstorm WarningCTPYork49 min
Jul 7, 1:04 PM EDTSevere Thunderstorm WarningCTPAdams26 min
Jul 7, 1:45 PM EDTSevere Thunderstorm WarningCTPYork30 min

Nearby

Tornado Warnings in Pennsylvania, 1991Every tornado warning in 1991Tornadoes 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.