Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 49, NWS Pittsburgh, PA

June 30, 1990Bedford County, Cambria County, Somerset County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Jun 30, 1990, 6:20 PM EDT for Bedford County, Cambria County, Somerset County, Pennsylvania. It was in force for 55 min.

The area

The counties it named.

The facts

Issued
Jun 30, 1990, 6:20 PM EDT (22:20 UTC)
Expired
Jun 30, 1990, 7:15 PM EDT
In force
55 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Bedford County, PA, Cambria County, PA, Somerset County, PA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 10.3 hours before the alert went out and 118 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 1990-06-30Temperature 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 1990-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
NaN m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
87 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 KPIT 302226
SVRPIT
PAC003-005-009-021-063-111-129-302315-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
620 PM EDT SAT JUN 30 1990
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  715 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN WEST PENNSYLVANIA
          ...ALLEGHENY...ARMSTRONG...BEDFORD...CAMBRIA...INDIANA
          ...SOMERSET...WESTMORELAND
 
RADAR CONTINUED TO SHOW SEVERAL SEVERE STORMS MOVING SOUTHEASTWARD AT
35 MPH. ONE WAS GOING THROUGH ARMSTRONG AND INDIANA COUNTIES INTO
CAMBRIA COUNTY.  ANOTHER WAS GOING THROUGH ALLEGHENY INTO WESTMORELAND
 COUNTY...AND ANOTHER TWO WERE MOVING THROUGH SOMERSET INTO BEDFORD COUN 
THESE ARE DANGEROUS STORMS WITH NUMEROUS REPORTS OF DOWNED TREES AND
POWER LINES...LARGE HAIL AND DANGEROUS LIGHTNING...AND BRIEFLY FLOODED
ROADS.  WHEN A SEVERE STORMS APPROACHES...TAKE COVER INDOORS AND AWAY
FROM GLASS.  IF YOU ARE IN A FLOOD PRONE AREA...LOOKOUT FOR REPEATED
HEAVY DOWNPOURS.  IF YOU MUST GO TO HIGHER GROUND...DONT GO THROUGH
FLOODING TO GET THERE.

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 30, 4:42 PM EDT, 1 hour 38 minutes before
PAZ001>006-013>015-WVZ001-302200-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE PITTSBURGH PA
445 PM EDT SAT JUN 30 1990

...SEVERE THUNDERSTORM WATCH FOR THE NORTHERN WEST VIRGINIA PANHANDLE
   AND MOST OF WESTERN PENNSYLVANIA TIL 10 PM...

JUST BEFORE 4 PM...RADAR SHOWED A THUNDERSTORM WITH STRONG WIND...
DANGEROUS LIGHTNING AND HEAVY DOWNPOURS MOVING INTO LAWRENCE BEAVER
SOUTHERN BUTLER AND WESTERN ALLEGHENY COUNTIES.  MOVEMENT WAS TO THE
SOUTHEAST AT 40 MILES AN HOUR.  THERE WERE OTHER STRONG STORMS OVER
WESTMORELAND COUNTY MOVING INTO THE JOHNSTOWN AREA AND ANOTHER OVER
BLAIR COUNTY MOVING INTO NORTHERN BEDFORD AND HUNTINGDON COUNTIES.

IF A STRONG STORM APPROACHES...TAKE COVER INDOORS AND AWAY FROM GLASS.
REMEMBER ALSO HEAVY DOWNPOURS CAN CAUSE FLOODING.
A WATCH OR WARNING IS ISSUED.

THERE IS SOME LIGHT AT THE END OF THE TUNNEL IN THE FORM OF A COLD
FRONT MOVING IN FROM THE UPPER MIDWEST. IT IS EXPECTEHD TO CROSS WESTERN
PENNSYLVANIA LATER TONIGHT FINALLY BRINGING A BREAK IN THE HEAT AND
HUMIDITY FOR SUNDAY.

RWH

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 4:49 PM EDTSevere Thunderstorm WarningPBZAllegheny, Beaver56 min
Jun 30, 5:26 PM EDTSevere Thunderstorm WarningPBZSomerset, Westmoreland64 min
Jun 30, 5:26 PM EDTSevere Thunderstorm WarningPBZButler64 min
Jun 30, 5:40 PM EDTSevere Thunderstorm WarningPBZAllegheny, Armstrong50 min
Jun 30, 6:20 PM EDTSevere Thunderstorm WarningPBZAllegheny, Armstrong, Indiana, Westmoreland55 min
Jun 30, 6:40 PM EDTSevere Thunderstorm WarningPBZFayette, Washington65 min
Jun 30, 7:03 PM EDTSevere Thunderstorm WarningPBZClearfield57 min
Jun 30, 7:19 PM EDTSevere Thunderstorm WarningPBZArmstrong, Westmoreland41 min
Jun 30, 7:19 PM EDTSevere Thunderstorm WarningPBZBedford, Cambria41 min
Jun 30, 7:56 PM EDTFlash Flood WarningPBZArmstrong, Butler, Fayette, Washington, Westmoreland64 min
Jun 30, 7:56 PM EDTFlash Flood WarningPBZClarion, Jefferson64 min
Jun 30, 7:56 PM EDTFlash Flood WarningPBZClearfield64 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1990Every severe thunderstorm warning in 1990

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.