Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 7, NWS Pittsburgh, PA

April 27, 1987Allegheny County, Beaver County, Butler County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Apr 27, 1987, 6:45 PM EDT for Allegheny County, Beaver County, Butler County, Pennsylvania. It was in force for 75 min. 6 reports 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 27, 1987, 6:45 PM EDT (22:45 UTC)
Expired
Apr 27, 1987, 8:00 PM EDT
In force
75 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Allegheny County, PA, Beaver County, PA, Butler County, PA

The radar

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

What was reported inside it

TimeReportWhereRemark
Apr 27, 6:55 PM EDTThunderstorm Wind 0Beaver, PA
Apr 27, 7:20 PM EDTThunderstorm Wind 0Beaver, PA
Apr 27, 7:50 PM EDTThunderstorm Wind 0Beaver, PA
Apr 27, 7:50 PM EDTThunderstorm Wind 0Butler, PA
Apr 27, 8:00 PM EDTThunderstorm Wind 0Allegheny, PA
Apr 27, 8:00 PM EDTThunderstorm Wind 0Allegheny, 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

Pittsburgh, PA (KPIT), launched 12:00Z, 10.8 hours before the alert went out and 31 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 1987-04-27Temperature 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 1987-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
2356 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
86 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.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 27, 7:50 PM EDTSevere Thunderstorm WarningPBZArmstrong, Westmoreland70 min
Apr 27, 7:50 PM EDTSevere Thunderstorm WarningPBZAllegheny, Beaver, Butler40 min
Apr 27, 6:45 PM EDTSevere Thunderstorm WarningPBZBrooke, Hancock, Ohio75 min
Apr 27, 6:45 PM EDTSevere Thunderstorm WarningPBZMarshall75 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1987Every severe thunderstorm warning in 1987

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.