Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 202, NWS State College, PA

July 29, 2007Franklin County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 29, 2007, 12:19 PM EDT for Franklin County, Pennsylvania. It was in force for 56 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, 2007, 12:19 PM EDT (16:19 UTC)
Expired: Jul 29, 2007, 1:15 PM EDT
In force: 56 min
Issued by: NWS State College, PA
Area: Counties, with a storm outline in the text

County Franklin County, PA

The radar

The Sterling radar (KLWX), 108 km from the middle of the area, began a volume at 16:19 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.3 hours before the alert went out and 112 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1003 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 792 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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, 9:51 AM EDT, 2 hours 28 minutes earlier.

Area forecast discussion, Jul 29, 9:51 AM EDT, 2 hours 28 minutes before

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Hazardous weather outlook, Jul 29, 4:45 AM EDT, 7 hours 34 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
445 AM EDT SUN JUL 29 2007

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-300845-
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-MONTOUR-
NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND-
ADAMS-YORK-LANCASTER-
445 AM EDT SUN JUL 29 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL FORM TODAY IN THE VICINITY OF A
STALLED FRONTAL BOUNDARY ACROSS SOUTHEAST PENNSYLVANIA. A FEW OF
THESE STORMS COULD BECOME SEVERE THIS AFTERNOON ACROSS THE LOWER
SUSQUEHANNA VALLEY. LARGE HAIL...DAMAGING WIND GUSTS AND EXCESSIVE
RAINFALL ARE POSSIBLE IN A FEW ISOLATED SPOTS ACROSS THIS AREA
BETWEEN LATE MORNING AND EARLY EVENING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

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, 6:33 AM EDT, 5 hours 46 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
633 AM EDT SUN JUL 29 2007

PAZ066-291100-
LANCASTER-
633 AM EDT SUN JUL 29 2007

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL LANCASTER COUNTY...

AT 632 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTHEAST OF NEW HOLLAND...MOVING EAST AT
15 MPH.

WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER
TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM
APPROACHES.

THIS STORM WILL BE NEAR CHURCHTOWN AROUND 700 AM.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 286 AND 295.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 322.

FORECASTER: MARTIN

Special weather statement, Jul 29, 8:05 AM EDT, 4 hours 14 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
805 AM EDT SUN JUL 29 2007

PAZ066-291245-
LANCASTER-
805 AM EDT SUN JUL 29 2007

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN LANCASTER COUNTY...

AT 759 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES SOUTHWEST OF WILLOW STREET...MOVING
NORTHEAST AT 10 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM. VERY HEAVY RAIN
WILL FALL FROM THIS STORM. RADAR ESTIMATES SUGGEST VERY HEAVY RAIN
IS POSSIBLE IN A SHORT PERIOD OF TIME AS THE STORM MOVES EASTWARD. HEAVY
RAIN WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL ROADSIDE
DITCHES AND SMALL STREAMS.

THIS STORM WILL BE NEAR SMITHVILLE AROUND 825 AM...WILLOW STREET
AROUND 830 AM...QUARRYVILLE AROUND 840 AM AND STRASBURG AROUND 845
AM.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 30...ROUTE
222.

FORECASTER: GRUMM

Special weather statement, Jul 29, 8:58 AM EDT, 3 hours 21 minutes before

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Special weather statement, Jul 29, 12:04 PM EDT, 15 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 2:33 AM EDT	Severe Thunderstorm Warning	CTP	Huntingdon	27 min
Jul 29, 5:52 AM EDT	Flash Flood Warning	CTP	Lancaster	3 hr
Jul 29, 8:13 AM EDT	Severe Thunderstorm Warning	CTP	Lancaster	62 min
Jul 29, 8:41 AM EDT	Flash Flood Warning	CTP	Lancaster	3 hr
Jul 29, 3:23 PM EDT	Severe Thunderstorm Warning	CTP	Mifflin	44 min
Jul 29, 4:05 PM EDT	Severe Thunderstorm Warning	CTP	Centre	44 min
Jul 29, 4:47 PM EDT	Severe Thunderstorm Warning	CTP	Union	58 min
Jul 29, 5:07 PM EDT	Severe Thunderstorm Warning	CTP	Northumberland	53 min
Jul 29, 6:16 PM EDT	Severe Thunderstorm Warning	CTP	Franklin	59 min
Jul 29, 6:53 PM EDT	Severe Thunderstorm Warning	CTP	Lebanon	67 min
Jul 29, 7:14 PM EDT	Severe Thunderstorm Warning	CTP	Franklin	46 min
Jul 29, 7:51 PM EDT	Severe Thunderstorm Warning	CTP	Cumberland, Dauphin, Perry	54 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2007 Every severe thunderstorm warning in 2007

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.