Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 131, NWS State College, PA

August 12, 1997Bedford County, Somerset County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Aug 12, 1997, 5:36 PM EDT for Bedford County, Somerset County, Pennsylvania. It was in force for 69 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 12, 1997, 5:36 PM EDT (21:36 UTC)
Expired
Aug 12, 1997, 6:45 PM EDT
In force
69 min
Issued by
NWS State College, PA
Area
Whole counties

Counties Bedford County, PA, Somerset County, PA

The radar

The State College radar (KCCX), 122 km from the middle of the area, began a volume at 21:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 9.6 hours before the alert went out and 123 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, Pittsburgh, PA at 12:00Z on 1997-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Pittsburgh, PA at 12:00Z on 1997-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
544 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
140 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 KCTP 122138 RRA
SVRCTP
PAC009-111-122245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
536 PM EDT TUE AUG 12 1997
 
THE NATIONAL WEATHER SERVICE IN STATE COLLEGE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  645 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...S...
 
IN  PENNSYLVANIA
 
   ...BEDFORD COUNTY...SOMERSET COUNTY
 
SEVERE THUNDERSTORMS CONTINUE TO MOVE ACROSS BEDFORD AND SOMERSET
COUNTIES.
 
THE WORST STORMS AT 530 PM WERE FROM NEAR WATERSIDE IN BEDFORD
COUNTY...WESTWARD TO NEAR DAVIDSVILE IN SOMERSET COUNTY.
 
THE STORMS WILL CONTINUE TO MOVE EAST AT 20 MPH.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE 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.
 L
MARTIN

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.

NWS State College, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 12, 2:11 PM EDT, 3 hours 25 minutes earlier.

Area forecast discussion, Aug 12, 2:11 PM EDT, 3 hours 25 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
210 PM EDT TUE AUG 12 1997

...SUGGESTIONS...

...PIT/PHL...HAVE TO WORD THE "EVENING" TO DEAL WITH SMALL BATCH OF
CONVECTION WHICH SHOULD FOLLOW LI GRADIENT ALONG MD BORDER
COUNTIES. ACTIVITY HASN'T SHOWN SIGNS OF SHRINKING OR GROWING. WUD
THINK IT WILL DIE OFF WITH LOSS OF HEATING.

FOR OVERNIGHT AND WED...LOOKS LIKE BULK OF PRECIP WILL FALL MAINLY
OVER OUR CWA FROM AROUND 06-15Z. ONLY SUGGESTION TO ZONE WORDING
WOULD BE TO HAVE "RAIN DEVELOPING" TONIGHT...BY AROUND MIDNIGHT WUD
PROBABLY WORK IN THE WEST...AFTER MIDNIGHT IN THE EAST. FOR WED WUD
DESCRIBE CONDITIONS IMPROVING DURING THE AFTERNOON. WILL LINGER
LONGEST OVER FAR SE WHERE MORE GENERALIZED WORDING WUD SUFFICE.

...DISCUSSION...
CONFIDENCE IN SIG SEVERE WX OUTBREAK FOR WED DWINDLING WITH TIME
AND THE RECEPTION OF THE 12Z PACKAGE.

WARM FRONT ALONG MASON-DIXON LINE ACTING TO FOCUS SOME CONVERGENCE
AND INSTABILITY SETTING OFF A SMALL AREA OF TRW MOVING THRU
SOMERSET CTY INTO BEDFORD. THIS ACTIVITY SHUD MOVE EAST ALONG LI
RIBBON AFFECTING MAINLY MD BORDER REGION.

FOR THE BIGGER PICTURE WARM FRONT LIFTS NORTH QUICKLY THRU THE
REGION BRINGING GENERALIZED BENEFICIAL RAINS OVERNIGHT AND ERLY
WED. STRONGEST ISENTROPIC LIFT STILL LOOKS TO SURGE WEST OF CWA BUT
SIG LIFT STILL GENERATED OUT AHEAD OF SFC LOW AND ATTENDING UPPER
TROF. BOTH ETA AND NGM DEVELOP A PREFRONTAL TROF WHICH THEY USE TO
FOCUS BEST RAINS SOMETIME BETWEEN ABOUT 06 AND 15Z.

NEW RUN SHOWS PV MAX BEING ABSORBED AND PASSING THRU REGION DURING
THE MORNING HOURS. IN FACT BY 18Z ETA AND NGM AGREE IN HAVING
REGION UNDER NVA. THINK THIS PUTS KISS OF DEATH ON POTENTIAL FOR
WIDESPREAD SEVERE. COLD FRONT AND HIGH THETA-E AIR GET OVERRUN BY
THE UPPER TROF THUS LOSING BEST SUPPORT. BUT WITH MUCH OF ERN CWA
IN WARM AIR THRU THE DAY...CANNOT LEAVE THUNDER OUT OF THE
FORECAST. THINK HOWEVER THAT WORDING COULD BE ENHANCED TO SUGGEST
WORST WX WILL BE DURING 1ST HALF OF DAY...AND THAT PM HOURS WILL
SEE IMPROVING CONDITIONS.

LA CORTE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 4:29 PM EDTSevere Thunderstorm WarningCTPBedford, Somerset61 min
Aug 12, 4:57 PM EDTFlash Flood WarningCTPBedford, Somerset3 hr
Aug 12, 6:10 PM EDTFlash Flood WarningCTPCambria3 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1997Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.