Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 66, NWS State College, PA

October 18, 1990Centre County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Oct 18, 1990, 12:40 PM EDT for Centre County, Pennsylvania. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Oct 18, 1990, 12:40 PM EDT (16:40 UTC)
Expired
Oct 18, 1990, 1:45 PM EDT
In force
65 min
Issued by
NWS State College, PA
Area
Whole counties

County Centre 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, 4.7 hours before the alert went out and 200 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 1990-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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 1990-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 447 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
18 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
934 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
447 m²/s²
0-3 km storm-relative helicity
467 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 KHAR 181639 RRA
SVRHAR
PAC027-181745-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HARRISBURG PA
1240 PM EDT THU OCT 18 1990
 
THE NATIONAL WEATHER SERVICE IN HARRISBURG HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  145 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN CENTRAL PENNSYLVANIA
          ...CENTRE
 
WE HAVE RECEIVED REPORTS OF WINDS GUSTS IN THE STATE COLLEGE AREA OF
74 MILE AN HOUR. THERE WERE FREQUENT GUSTS OF 50 TO 60 MILES AND HOUR.
THERE WERE SHOWERS AND POSSIBLY A FEW THUNDERSTORMS ALONG WITH THE
HIGH WINDS.
 
THESE HIGH WINDS WERE OCCURING IN ADVVANCE OF A STRONG COLD FRONT
MOVING EAST ACROSS THE STATE.
 
 
 
 
 
IF TH=REATENING WEATHER APPROACHES YOU SHOULD GO TO A SAFE
PLACE IMMEDIATELY AND ASK THE NEAREST LAW ENFORCEMENT AGENCY
TO RELAY YOUR SEVERE WEATHER REPORTS TO THE LOCAL NATIONAL
WEATHER SERVICE OFFICE.

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, Oct 18, 11:59 AM EDT, 41 minutes before
PAZ006-008-009-013-181800-
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HARRISBURG PA
1155 AM EDT THU 0CT 18 1990

...SHOWERS AND GUSTY WINDS ARE MOVING INTO CENTRAL PENNSYLVANIA...

GUSTY WINDS WILL ACCOMPANY THE SHOWERS AS THEY MOVE ACROSS THE STATE TODAY.
STATE COLLEGE REPORTED A WIND GUST OF ABOUT 60 MILES AN HOUR AS SHOWERS WERE
MOVING THROUGH...SHORTLY AFTER 1140 AM...AND GUSTS OF 40 TO 50 MILES
AN HOUR WERE NOT UNCOMMON.

AT 1129 AM EDT THE NATIONAL WEATHER SERVICE RADAR IN HARRISBURG WAS SHOWING
SHOWERS OVER CENTRAL PENNSYLVANIA...THE WESTERN PANHANDLE OF MARYLAND...
NORTHERN VIRGINIA...AND THE EXTREME NORTHEAST SECTIONS OF WEST VIRGINIA.

MOST OF THE SHOWERS STRETCHED FROM THE NORTHERN MOUNTAINS...SOUTH ACROSS
THE LAUREL AND CENTRAL MOUNTAINS...THE WESTERN PORTIONS OF THE SUSQUEHANNA
VALLEY...THE WESTERN PANHANDLE OF MARYLAND AND DOWN INTO NORTHERN VIRGINIA.
.
THERE WERE ALSO A FEW AREAS OF HEAVY RAIN...MOST OF WHICH WERE IN A THIN LINE
BETWEEN STATE COLLEGE AND MERCERSBURG.

MOVEMENT OF THE SHOWERS WAS NORTHEAST AT ABOUT 55 MILES AN HOUR.

WSO HAR RBH

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 18, 4:38 PM EDTFlash Flood WarningCTPYork2 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.