Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 75, NWS Pittsburgh, PA

July 20, 1990Armstrong County, Butler County, Clarion County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Jul 20, 1990, 2:12 PM EDT for Armstrong County, Butler County, Clarion County, Pennsylvania. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1990, 2:12 PM EDT (18:12 UTC)
Expired
Jul 20, 1990, 3:15 PM EDT
In force
63 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Armstrong County, PA, Butler County, PA, Clarion 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, 6.2 hours before the alert went out and 75 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 1990-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 66 joules per kilogram.LCLLFCEL10008507005003002001001 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 1990-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
66 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1131 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
117 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
Jul 20, 2:55 PM EDTFlash Flood WarningPBZWestmoreland65 min
Jul 20, 2:55 PM EDTSevere Thunderstorm WarningPBZWestmoreland65 min
Jul 20, 4:12 PM EDTSevere Thunderstorm WarningPBZCambria63 min
Jul 20, 4:12 PM EDTSevere Thunderstorm WarningPBZGreene63 min
Jul 20, 4:24 PM EDTSevere Thunderstorm WarningPBZSomerset66 min
Jul 20, 5:01 PM EDTFlash Flood WarningPBZFayette, Somerset119 min
Jul 20, 5:01 PM EDTSevere Thunderstorm WarningPBZFayette, Somerset119 min
Jul 20, 6:29 PM EDTFlash Flood WarningPBZButler2 hr

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.