Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 12, NWS Pittsburgh, PA

April 24, 2009Fayette County, Greene County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Apr 24, 2009, 7:45 AM EDT for Fayette County, Greene County, Pennsylvania. It was in force for 30 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: Apr 24, 2009, 7:45 AM EDT (11:45 UTC)
Expired: Apr 24, 2009, 8:15 AM EDT
In force: 30 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon

Counties Fayette County, PA, Greene County, PA

The radar

The Pittsburgh radar (KPBZ), 76 km from the middle of the area, began a volume at 11:46 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

Pittsburgh, PA (KPIT), launched 00:00Z, 11.8 hours before the alert went out and 60 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2245 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 95 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Pittsburgh, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 24, 1:31 AM EDT, 6 hours 14 minutes earlier.

Area forecast discussion, Apr 24, 1:31 AM EDT, 6 hours 14 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
131 AM EDT FRI APR 24 2009

.SYNOPSIS...
WARM TEMPERATURES AND SUNSHINE EXPECTED THROUGH THE WEEKEND. A POP
UP SHOWER OR STORM IS POSSIBLE THIS AFTERNOON AND AGAIN ON SUNDAY
AFTERNOON.

&&

.NEAR TERM /THROUGH TODAY/...
STRONG WARM FRONT WILL PUSH THROUGH THIS MORNING. BEHIND THIS
BOUNDARY...WARM AIR AND LL MOISTURE WILL STREAM NORTHWARD. WITH
THE INFLUX OF HIGH SFC TDS...LL ATMOSPHERE WILL DESTABILIZE. AN
UL WAVE WILL MOVE OVER THE AREA THIS AFTERNOON. THIS WAVE MAY BE
ENOUGH TO DEVELOP A SHOWER OR STORM...MAINLY ACROSS THE NORTH.
THERE ARE SOME LIMITING FACTORS AS DEEP MOISTURE IS ABSENT AND
FORECAST SOUNDINGS CONTINUE TO SHOW STRONG CAPPING. WILL PUT IN A
MENTION FROM PIT NORTH THIS AFTERNOON AS WELL AS AN INCREASE IN
CLOUD COVER.

MUCH ABOVE NORMAL TEMPS TODAY.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
UL WAVE MOVES NORTHWARD TONIGHT AND RIDGE BUILDS IN FOR THE
WEEKEND. THIS WILL MEAN A CONTINUATION OF WELL ABOVE NORMAL TEMPS
AND DRY WEATHER.

THE WARM FRONT...THAT WILL CROSS THE AREA TODAY...TRIES TO SETTLE
SOUTHWARD SUNDAY AFT AS A BACK DOOR COLD FRONT. SOME DIFFERENCES
IN SOLUTIONS HERE AS NAM...AND TO SOME EXTENT...21Z SREF WANT TO
PUSH BOUNDARY FAR ENOUGH SOUTH TO DEVELOP SHOWERS ACROSS NORTHERN
HALF OF THE AREA. THE PROBLEM IS THERE IS NOT MUCH UL PUSH TO HELP
TO MOVE THIS FRONT SOUTHWARD. WILL GO WITH A SMALL CHANCE FOR
ACTIVITY ACROSS THE NORTH SUNDAY AFT.

ABOVE NORMAL TEMPS AGAIN SUNDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EXTENDED REMAINS DRY THROUGH MONDAY. NEXT SYSTEM PUSHES THROUGH
TUESDAY AND VERY SLOWLY MOVES SOUTHEASTWARD THROUGH WED. THIS WILL
BE THE NEXT GOOD CHANCE FOR ACTIVITY.

SOME DIFFERENCES AT THE END OF THE EXT PERIOD...DEPENDING ON HOW
FAR SOUTH FRONT ADVANCES.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SOUTHERLY SURFACE FLOW WILL DEVELOP TONIGHT AS HIGH PRESSURE
SHIFTS EAST OF THE UPPER OHIO. MID AND HIGH CLOUDS MAY ALSO BE
EXPECTED IN THE HOURS AROUND DAWN AS WARM FRONT SHIFTS NORTHWARD.
BY AFTERNOON, SOME HIGH BASED CUMULUS SHOULD DEVELOP IN THE WARMTH
AND IMPROVING MOISTURE SUPPLY, ALONG WITH THE SOUTHWEST WIND
GUSTING TO 20KT WITH THE AFTERNOON MIXING.

SURFACE LOW PRESSURE IS PROGGED TO DEVELOP OVER THE GREAT LAKES
DURING THE NEXT 24 HOURS. RESULTING PRESSURE GRADIENT SHOULD SPAWN A
HEALTHY LOW LEVEL JET ON FRIDAY NIGHT...HENCE, POTENTIAL FOR SOME
LOW LEVEL WIND SHEAR MAY BE ANTICIPATED WITH THE OVERNIGHT
DECOUPLING.

VFR CONDITIONS ARE FORECAST TO PREVAIL INTO EARLY NEXT WEEK AS UPPER
HIGH PRESSURE MAINTAINS POSITION OVER THE EASTERN CONUS.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

Hazardous weather outlook, Apr 24, 4:24 AM EDT, 3 hours 21 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
424 AM EDT FRI APR 24 2009

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-250830-
GARRETT-TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-
JEFFERSON OH-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER-VENANGO-
FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER-ALLEGHENY-
ARMSTRONG-INDIANA-WASHINGTON-WESTMORELAND-GREENE-FAYETTE-HANCOCK-
BROOKE-OHIO-MARSHALL-WETZEL-MARION-MONONGALIA-PRESTON-TUCKER-
424 AM EDT FRI APR 24 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...EAST
CENTRAL OHIO...NORTHWEST PENNSYLVANIA...SOUTHWEST
PENNSYLVANIA...WEST CENTRAL PENNSYLVANIA...NORTHERN WEST VIRGINIA
AND NORTHERN PANHANDLE OF WEST VIRGINIA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

In the hours before

Local storm report, Apr 24, 7:03 AM EDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
703 AM EDT FRI APR 24 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0701 AM     HAIL             WHEELING                40.08N 80.70W
04/24/2009  E0.50 INCH       OHIO               WV   PUBLIC

&&

JP

Special weather statement, Apr 24, 7:13 AM EDT, 32 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
713 AM EDT FRI APR 24 2009

PAZ007-008-013-014-241145-
BUTLER PA-LAWRENCE PA-MERCER PA-VENANGO PA-
713 AM EDT FRI APR 24 2009

...THUNDERSTORMS WITH HAIL...

THUNDERSTORMS WITH WITH PEA AND MARBLE SIZED HAIL TO MOVE THROUGH
THE FOLLOWING COUNTIES...
BUTLER...VENANGO...MERCER AND LAWRENCE...

AT 712 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH
INDICATED THUNDERSTORMS WITH WITH PEA AND MARBLE SIZED HAIL ALONG A
LINE EXTENDING FROM 20 MILES NORTH OF SHARON TO 6 MILES SOUTHWEST OF
FARRELL...MOVING EAST AT 40 MPH.

SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE...
  ENTERPRISE...FARRELL...FREDONIA...GROVE CITY...HERMITAGE...MAURICE
  K GODDARD STATE PARK...MERCER...MOUNT PLEASANT...NEW WILMINGTON...
  OAKLAND...POLK...SHARON...STONEBORO...AMSTERDAM AND ARMSTRONG

KEEP AN EYE TO THE SKY AND MOVE TO A SAFE PLACE IF THUNDERSTORMS
APPROACH.

PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL
WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772.

Local storm report, Apr 24, 7:29 AM EDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
729 AM EDT FRI APR 24 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0726 AM     HAIL             SHARON                  41.23N 80.50W
04/24/2009  E0.50 INCH       MERCER             PA   PUBLIC

0726 AM     HAIL             HERMITAGE               41.23N 80.44W
04/24/2009  E0.25 INCH       MERCER             PA   PUBLIC

&&

JP

Local storm report, Apr 24, 7:37 AM EDT, 8 minutes before

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Local storm report, Apr 24, 7:40 AM EDT, 5 minutes before

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Special weather statement, Apr 24, 7:42 AM EDT, 3 minutes before

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  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
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      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 24, 7:35 AM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington, Westmoreland	25 min
Apr 24, 9:24 AM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	36 min
Apr 24, 9:38 AM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Indiana, Jefferson	37 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009 Every 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.