Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Pittsburgh, PA

August 4, 2021Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this special weather statement at Aug 4, 2021, 4:03 PM EDT for Westmoreland County, Pennsylvania. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 4, 2021, 4:03 PM EDT (20:03 UTC)
Expired
Aug 4, 2021, 4:30 PM EDT
In force
27 min
Issued by
NWS Pittsburgh, PA

County Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 43 km from the middle of the area, began a volume at 20:05 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, 8.1 hours before the alert went out and 30 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 2021-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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, Pittsburgh, PA at 12:00Z on 2021-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
52 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1110 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

049 
WWUS81 KPBZ 042003
SPSPBZ

Special Weather Statement
National Weather Service Pittsburgh PA
403 PM EDT Wed Aug 4 2021

PAZ021-073-042030-
Westmoreland-Allegheny-
403 PM EDT Wed Aug 4 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL ALLEGHENY AND WEST
CENTRAL WESTMORELAND COUNTIES...

At 402 PM EDT, a strong thunderstorm was located over Trafford, or
near Monroeville. The storm is nearly stationary.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Penn Hills, Monroeville, Plum, Murrysville, North Versailles, White
Oak, Wilkins Township, Duquesne, Turtle Creek, North Braddock, Irwin,
and Pitcairn.

This includes the following highways...
  Pennsylvania Turnpike between mile markers 54 and 67.
  Interstate 376 in Pennsylvania between mile markers 82 and 84.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4038 7986 4051 7975 4045 7954 4029 7970
TIME...MOT...LOC 2002Z 301DEG 3KT 4037 7973 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 6:15 PM EDTSpecial Weather StatementPBZButler30 min
Aug 4, 6:54 PM EDTSpecial Weather StatementPBZOhio36 min
Aug 4, 7:31 PM EDTAreal Flood AdvisoryPBZMarshall, Ohio8 min
Aug 4, 7:39 PM EDTFlash Flood WarningPBZMarshall, Ohio111 min
Aug 4, 6:19 PM EDTSpecial Weather StatementPBZBelmont26 min

Nearby

Special Weather Statements in Pennsylvania, 2021Every special weather statement in 2021

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.