Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 87, NWS State College, PA

July 9, 1997York County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 9, 1997, 4:39 PM EDT for York County, Pennsylvania. It was in force for 66 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
Jul 9, 1997, 4:39 PM EDT (20:39 UTC)
Expired
Jul 9, 1997, 5:45 PM EDT
In force
66 min
Issued by
NWS State College, PA
Area
Whole counties

County York County, PA

The radar

The Sterling radar (KLWX), 124 km from the middle of the area, began a volume at 20:39 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.

What was reported inside it

TimeReportWhereRemark
Jul 9, 4:45 PM EDTThunderstorm Wind 51Newberrytown, 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 9, 1:15 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.7 hours before the alert went out and 73 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, Phillips Aaf/Abe, MD at 12:00Z on 1997-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 189 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 1997-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.1939Sfc1 km3 km6 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
189 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1364 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
25 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 KCTP 092037 RRA
SVRCTP
PAC133-092145-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
439 PM EDT WED JUL 9 1997
 
THE NATIONAL WEATHER SERVICE IN STATE COLLEGE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  545 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS......
 
IN  PENNSYLVANIA
 
   ...YORK COUNTY
 
AT 436 PM RADAR SHOWED A SEVERE THUNDERSTORM NEAR ROSSVILLE IN NORTHERN
YORK COUNTY. THIS STORM WILL MOVE INTO LANCASTER COUNTY BY 450 PM.
 
ANOTHER SEVERE THUNDERSTORM OVER ADAMS COUNTY MAY MOVE INTO WESTERN YORK
COUNTY NEAR HANNOVER AROUND 5 PM.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

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.

NWS State College, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 9, 2:39 PM EDT, 2 hours earlier.

Area forecast discussion, Jul 9, 2:39 PM EDT, 2 hours before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
235 PM EDT WED JUL 9 1997

...DISCUSSION...
QUITE BUSY SO WILL BE BRIEF...
LINE OF SHOWERS AND TSTMS (ORIENTED NE-SW) SLIDING SE ACROSS
CENTRAL PA ATTM. HAD A CELL POP IN S HUNTINGDON CNTY THAT HAD A VIL
OF 53. NO REPORTS OF DAMAGE YET HOWEVER.

LINE OF TRW DEVELOPING AHEAD OF SFC COLD FRONT. EXPECT TRW ACTIVITY
TO BE SVR (STRONG WINDS AND HAIL) ACROSS LOWER SUS IN CTP CWA NXT
1-3 HRS.

X-SECT'S FCST DRY AIR TO RAPIDLY INVADE PA TONIGHT SO CLEARING
AFTER SUNSET FROM WEST TO EAST.

SFC HIGH PRESSURE TO SLIDE INTO FCST/A ON THU BRINGING LOWER
HUMIDITY AND SUNNY SKIES (A REAL NICE DAY).

WINTHER

In the hours before

Special weather statement, Jul 9, 11:04 AM EDT, 5 hours 35 minutes before
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066-092200-

SPECIAL WEATHER STATEMENT - SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1105 AM EDT WED JUL 9 1997

...A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
PENNSYLVANIA THIS AFTERNOON...

THE STORM PREDICTION CENTER IN NORMAN OKLAHOMA SAYS THERE IS A
SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE AND LOWER
SUSQUEHANNA VALLEY THIS AFTERNOON AND EVENING.

A COLD FRONT WILL MOVE SLOWLY ACROSS EASTERN PENNSYLVANIA THIS
AFTERNOON WITH SHOWERS AND THUNDERSTORMS ACCOMPANYING IT.
AS THE FRONT ENTERS THE SUSQUEHANNA VALLEY THIS AFTERNOON
THE THUNDERSTORMS...BUOYED BY MID SUMMER H2EAT AND
HUMIDITY...COULD BECOME SEVERE.
SKYWARN ACTIVATION MAY BE NEEDED LATER TODAY.

WINTHER
Special weather statement, Jul 9, 11:05 AM EDT, 5 hours 34 minutes before
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066-092200-

SPECIAL WEATHER STATEMENT - SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1105 AM EDT WED JUL 9 1997

...A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
PENNSYLVANIA THIS AFTERNOON...

THE STORM PREDICTION CENTER IN NORMAN OKLAHOMA SAYS THERE IS A
SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE AND LOWER
SUSQUEHANNA VALLEY THIS AFTERNOON AND EVENING.

A COLD FRONT WILL MOVE SLOWLY ACROSS EASTERN PENNSYLVANIA THIS
AFTERNOON WITH SHOWERS AND THUNDERSTORMS ACCOMPANYING IT.
AS THE FRONT ENTERS THE SUSQUEHANNA VALLEY THIS AFTERNOON
THE THUNDERSTORMS...BUOYED BY MID SUMMER HEAT AND
HUMIDITY...COULD BECOME SEVERE.
SKYWARN ACTIVATION MAY BE NEEDED LATER TODAY.

WINTHER
Special weather statement, Jul 9, 1:47 PM EDT, 2 hours 52 minutes before
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-092400-

SPECIAL WEATHER STATEMENT...SEVERE THUNDERSTORM WATCH
NATIONAL WEATHER SERVICE STATE COLLEGE PA
150 PM EDT WED JULY 09 1997

...SEVERE THUNDERSTORM WATCH...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR MUCH OF SOUTH-CENTRAL AND SOUTEAST PENNSYLVANIA VALID UNTIL
8 PM.

THE SEVERE THUNDERSTORM WATCH INCLUDES THE FOLLOWING COUNTIES:

BLAIR... HUNTINGDON... BEDFORD... FULTON... FRANKLIN... MIFFLIN...
JUNIATA...SNYDER...NORTHUMBERLAND... SCHUYLKILL... PERRY...
DAUPHIN... LEBANON... CUMBERLAND... COLUMBIA... ADAMS... YORK AND
LANCASTER.

A COLD FRONT WILL CONTINUE MOVING ACROSS CENTRAL PENNSYLVANIA THIS
AFTERNOON. WARM HUMID AIR IN PLACE OVER THE REGION WILL SUPPORT THE
POTENTIAL FOR THUNDERSTORMS...SOME WHICH WILL CAUSE LARGE HAIL AND
STRONG DAMAGING WINDS.

THE COLD FRONT WILL SETTLE SOUTH OF THE AREA LATER TONIGHT BRINGING
AN END TO THE THREAT OF SEVERE STORMS.

WINTHER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 1:10 PM EDTSevere Thunderstorm WarningCTPBedford65 min
Jul 9, 1:42 PM EDTSevere Thunderstorm WarningCTPHuntingdon63 min
Jul 9, 2:50 PM EDTSevere Thunderstorm WarningCTPFulton55 min
Jul 9, 4:26 PM EDTSevere Thunderstorm WarningCTPFranklin64 min
Jul 9, 4:30 PM EDTSevere Thunderstorm WarningCTPAdams60 min
Jul 9, 4:35 PM EDTSevere Thunderstorm WarningCTPLancaster55 min
Jul 9, 6:00 PM EDTSevere Thunderstorm WarningCTPLancaster65 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1997Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.