Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 111, NWS State College, PA

July 29, 2009Dauphin County, Lebanon County, Schuylkill County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 29, 2009, 7:23 PM EDT for Dauphin County, Lebanon County, Schuylkill County, Pennsylvania. It was in force for 97 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 29, 2009, 7:23 PM EDT (23:23 UTC)
Expired
Jul 29, 2009, 9:00 PM EDT
In force
97 min
Issued by
NWS State College, PA
Area
Storm-based polygon

Counties Dauphin County, PA, Lebanon County, PA, Schuylkill County, PA

The radar

The State College radar (KCCX), 137 km from the middle of the area, began a volume at 23:24 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.4 hours before the alert went out and 119 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 2009-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1577 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
1577 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
745 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

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 29, 4:00 PM EDT, 3 hours 23 minutes earlier.

Area forecast discussion, Jul 29, 4:00 PM EDT, 3 hours 23 minutes before
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Hazardous weather outlook, Jul 29, 2:59 AM EDT, 16 hours 24 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
259 AM EDT WED JUL 29 2009

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049-050-
300700-
WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-
NORTHERN CENTRE-SOUTHERN CENTRE-CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-
JUNIATA-SOMERSET-BEDFORD-FULTON-FRANKLIN-TIOGA-NORTHERN LYCOMING-
SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-
259 AM EDT WED JUL 29 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

PAZ051>053-056>059-063>066-300700-
MONTOUR-NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-
CUMBERLAND-ADAMS-YORK-LANCASTER-
259 AM EDT WED JUL 29 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY...ALONG WITH
THE RISK OF LOCALIZED FLOODING FROM HEAVY DOWNPOURS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Special weather statement, Jul 29, 4:37 PM EDT, 2 hours 46 minutes before
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Special weather statement, Jul 29, 5:01 PM EDT, 2 hours 22 minutes before
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Special weather statement, Jul 29, 5:28 PM EDT, 1 hour 55 minutes before
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Local storm report, Jul 29, 6:20 PM EDT, 1 hour 3 minutes before
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Local storm report, Jul 29, 7:10 PM EDT, 13 minutes before
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Special weather statement, Jul 29, 7:11 PM EDT, 12 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 12:05 PM EDTSpecial Weather StatementCTPSchuylkill25 min
Jul 29, 2:05 PM EDTSpecial Weather StatementCTPNorthumberland40 min
Jul 29, 2:30 PM EDTSevere Thunderstorm WarningCTPColumbia, Northumberland45 min
Jul 29, 2:44 PM EDTSpecial Weather StatementCTPDauphin31 min
Jul 29, 3:03 PM EDTSevere Thunderstorm WarningCTPDauphin27 min
Jul 29, 3:21 PM EDTSpecial Weather StatementCTPFulton39 min
Jul 29, 4:01 PM EDTSpecial Weather StatementCTPFulton44 min
Jul 29, 4:24 PM EDTSpecial Weather StatementCTPLancaster51 min
Jul 29, 4:37 PM EDTSpecial Weather StatementCTPFranklin68 min
Jul 29, 4:52 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Franklin53 min
Jul 29, 5:01 PM EDTSpecial Weather StatementCTPFranklin14 min
Jul 29, 5:28 PM EDTSpecial Weather StatementCTPFranklin17 min
Jul 29, 5:38 PM EDTAreal Flood AdvisoryCTPFranklin3 hr
Jul 29, 5:46 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Franklin59 min
Jul 29, 7:11 PM EDTSpecial Weather StatementCTPSchuylkill79 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009Every severe thunderstorm warning in 2009

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.