Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 21, NWS Pittsburgh, PA

April 11, 1999Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Apr 11, 1999, 2:29 PM EDT for Westmoreland County, Pennsylvania. It was in force for 61 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
Apr 11, 1999, 2:29 PM EDT (18:29 UTC)
Expired
Apr 11, 1999, 3:30 PM EDT
In force
61 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County Westmoreland County, PA

What was reported inside it

TimeReportWhereRemark
Apr 11, 2:30 PM EDTHail 0.75Greensburg, 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.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 6.5 hours before the alert went out and 55 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 1999-04-11Temperature 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 1999-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.1939587897117Sfc1 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
506 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
560 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.

999 
WUUS1 KPIT 111830 RRA
SVRPIT
PAC129-111930-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
229 PM EDT SUN APR 11 1999

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTMORELAND COUNTY IN SOUTHWESTERN PENNSYLVANIA.

* UNTIL 330 PM EDT.

* AT 229 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM GREENSBURG...MOVING EAST AT 40 MPH.

* THIS SEVERE THUNDERSTORM WILL BE NEAR...
  LATROBE AT 245 PM.
  DERRY AT 250 PM.

<<CALL TO ACTION>>DAMAGING WINDS AND LARGE HAIL ARE LIKELY. GO
INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS

.END/JP


&

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, Apr 11, 12:45 PM EDT, 1 hour 44 minutes before
MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-112300-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
1245 PM EDT SUN APR 11 1999

...SEVERE THUNDERSTORM POTENTIAL LIMITED TO PA AND WV THIS AFTERNOON...

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS IN WESTERN PENNSYLVANIA...
AND NORTHERN WEST VIRGINIA EAST OF WETZEL COUNTY...AND IN GARRETT COUNTY
MARYLAND.

A COLD FRONT PUSHING THROUGH EASTERN OHIO HAS REDUCED THE THREATENED
AREA. WHILE THERE MAY BE A FEW THUNDERSTORMS IN EAST CENTRAL OHIO AND
THE NORTHERN PANHANDLE OF WEST VIRGINIA...NONE IS EXPECTED TO BE SEVERE.

THERE IS THREAT OF FLASH FLOODING THE EAST CENTAL OHIO AND THE NORTHERN
PANHANDLE OF WEST VIRGINIA UNTIL 4 PM. AND A THREAT OF FLOODING IN
THE REST OF NORTHERN WEST VIRGINIA...WESTERN PENNSYLVANIA...AND GARRETT
COUNTY MARYLAND UNTIL 10 PM TONIGHT.

SKYWARN ACTIVATION MAY BE NEEDED AFTER 2 PM.
Special weather statement, Apr 11, 12:45 PM EDT, 1 hour 44 minutes before
MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-112300-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
1245 PM EDT SUN APR 11 1999

...SEVERE THUNDERSTORM POTENTIAL LIMITED TO PA AND WV THIS AFTERNOON...

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS IN WESTERN PENNSYLVANIA...
AND NORTHERN WEST VIRGINIA EAST OF WETZEL COUNTY...AND IN GARRETT COUNTY
MARYLAND.

A COLD FRONT PUSHING THROUGH EASTERN OHIO HAS REDUCED THE THREATENED
AREA. WHILE THERE MAY BE A FEW THUNDERSTORMS IN EAST CENTRAL OHIO AND
THE NORTHERN PANHANDLE OF WEST VIRGINIA...NONE IS EXPECTED TO BE SEVERE.

THERE IS THREAT OF FLASH FLOODING THE EAST CENTAL OHIO AND THE NORTHERN
PANHANDLE OF WEST VIRGINIA UNTIL 4 PM. AND A THREAT OF FLOODING IN
THE REST OF NORTHERN WEST VIRGINIA...WESTERN PENNSYLVANIA...AND GARRETT
COUNTY MARYLAND UNTIL 10 PM TONIGHT.

SKYWARN ACTIVATION MAY BE NEEDED AFTER 2 PM.
Local storm report, Apr 11, 2:12 PM EDT, 17 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
212 PM EDT SUN APR 11 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0205 PM    MACOMBER                  WV   0.75 INCH HAIL
04/11/99   PRESTON                        SOUTH OF KINGWOOD IN
                                          LAUREL MOUNTAIN.

END
Local storm report, Apr 11, 2:12 PM EDT, 17 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
212 PM EDT SUN APR 11 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0205 PM    MACOMBER                  WV   0.75 INCH HAIL
04/11/99   PRESTON                        SOUTH OF KINGWOOD IN
                                          LAUREL MOUNTAIN.

END

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 11, 4:16 PM EDTSevere Thunderstorm WarningPBZMercer29 min
Apr 11, 4:32 PM EDTSevere Thunderstorm WarningPBZVenango43 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1999Every severe thunderstorm warning in 1999

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.