Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 20, NWS Pittsburgh, PA
NWS Pittsburgh, PA issued this severe thunderstorm warning at May 24, 2009, 1:51 PM EDT for Allegheny County, Beaver County, Pennsylvania. It was in force for 39 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
- May 24, 2009, 1:51 PM EDT (17:51 UTC)
- Expired
- May 24, 2009, 2:30 PM EDT
- In force
- 39 min
- Issued by
- NWS Pittsburgh, PA
- Area
- Storm-based polygon
Counties Allegheny County, PA, Beaver County, PA
The radar
The Pittsburgh radar (KPBZ), 7 km from the middle of the area, began a volume at 17:53 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 12:00Z, 5.9 hours before the alert went out and 19 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.
- Mixed-layer CAPE
- 218 J/kg
- Mixed-layer CIN
- -86 J/kg
- Mixed-layer LCL
- 1190 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 58 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 May 24, 9:40 AM EDT, 4 hours 11 minutes earlier.
Area forecast discussion, May 24, 9:40 AM EDT, 4 hours 11 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 940 AM EDT SUN MAY 24 2009 .SYNOPSIS... A WEAK FRONT WILL CONTINUE TO MEANDER OVER THE UPPER OHIO VALLEY REGION FOR THE NEXT COUPLE OF DAYS PROVIDING FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... NORTHEN STREAM SHORTWAVE WILL CROSS QUEBEC TODAY AND PROVIDE SUPPORT FOR THUNDERSTORMS FOCUSED VIA WEAK COLD FRONT ANALYZED FROM NEAR BRADFORD TO A LITTLE NORTH OF ZANESVILLE THIS MORNING. AFTERNOON HEATING AND DEWPOINTS ON EITHER SIDE OF 60F WILL PROVIDE LIMITED INSTABILITY, AND THAT FACTOR COMBINED WITH RATHER WEAK SHEAR AND MID LEVEL WIND, SHOULD INHIBIT SEVERE POTENTIAL. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH MARGINALLY MOIST SURFACE DEWPOINTS CONTINUING THE SOMEWHAT HUMID CONDITIONS. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... WITH LOW PRESSURE DIGGING OVER THE LOWER MISSISSIPPI VALLEY, TODAYS CANADIAN DISTURBANCE WILL NOT PULL THE FRONT VERY FAR TO THE SOUTH...POSSIBLY ACROSS WEST VIRGINIA AND SOUTHERN OHIO. SO, PRECIPITATION MENTION WILL REMAIN IN THE FORECAST FOR COUNTIES ROUGHLY FROM PITTSBURGH ON SOUTH. POP NUMBERS IN THE CHANCE CATEGORY SHOULD SUFFICE FOR NOW AS THAT AREA WILL ALSO BE UNDER THE INFLUENCE OF BUILDING RIDGE ON THE VAN OF THE AFORE-MENTIONED LOW. && .LONG TERM /TUESDAY THROUGH SATURDAY/... WARM AND HUMID CONDITIONS WILL RETURN AREAWIDE BY MID WEEK AS MOISTURE DEPTH/SUPPLY INCREASES IN ADVANCE OF PLAINS-STATES LOW PRESSURE. HOWEVER, EASTERN CONUS RIDGE WITH WARM MID LEVEL TEMPERATURES WILL LIMIT EXTENT AND POWER OF THUNDERSTORMS. SHOWERS WILL REMAIN IN THE FORECAST, BUT WILL ADJUST BETTER POP NUMBERS TO BETTER ALIGN WITH EXPECTED MID-WEEK BOUNDARY POSITIONING. FOR LATE WEEK, FORECAST WILL BE OF APPROACH AND PASSAGE OF NEXT COLD FRONT ACCOMPANIED BY MORE SHOWERS AND STORMS FOLLOWED BY A DRY WEEKEND UNDER HIGH PRESSURE. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... WEAK FRONTAL BOUNDARY STRETCHED ACROSS THE REGION WILL BE THE FOCUS FOR WIDELY SCATTERED THUNDERSTORMS THROUGH MONDAY. GENERALLY VFR FLIGHT CONDITIONS WILL CONTINUE TODAY. ISOLATED THUNDERSTORMS WILL CONTINUE TO POP UP ACROSS THE SOUTH EARLY THIS MORNING, BUT COVERAGE IS TOO SPARSE TO INCLUDE IN ANY TERMINALS. EXPECT VISIBILITIES TO BE REDUCED IN AREAS OF FOG AND HAZE AT SOUTHERN TERMINALS MAINLY BETWEEN 08Z-14Z SUNDAY. EXPECT SLIGHTLY GREATER COVERAGE OF THUNDERSTORMS SUNDAY AFTERNOON AS ADDITIONAL LOW LEVEL MOISTURE SHIFTS NORTHWARD AND BOUNDARY DIPS TO THE SOUTH. OVERALL VFR CONDITIONS STILL EXPECTED. MAINLY VFR CONDITIONS EXPECTED TO CONTINUE MONDAY WITH THE RISK FOR THUNDERSTORMS SOUTH OF KPIT. FOR TUESDAY NIGHT THROUGH THURSDAY THERE IS STILL A CHANCE FOR SHOWERS AND THUNDERSTORMS AND POSSIBLE RESTRICTIONS AS GFS ENSEMBLE SHOWS A LOW PRESSURE AREA MOVING FROM THE LOWER OHIO RIVER VALLEY TO THE MID ATLANTIC COAST. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && 15
Hazardous weather outlook, May 24, 5:01 AM EDT, 8 hours 50 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 501 AM EDT SUN MAY 24 2009 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029>032-WVZ001>004-012-021>023-041-250915- 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- 501 AM EDT SUN MAY 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...MONDAY THROUGH SATURDAY. 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
Special weather statement, May 24, 12:45 PM EDT, 1 hour 6 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1245 PM EDT SUN MAY 24 2009 OHZ050-PAZ029-WVZ001>003-241745- BROOKE WV-HANCOCK WV-JEFFERSON OH-OHIO WV-WASHINGTON PA- 1245 PM EDT SUN MAY 24 2009 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... JEFFERSON...WASHINGTON...OHIO...BROOKE AND HANCOCK... AT 1242 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED A CLUSTER OF THUNDERSTORMS ALONG A LINE EXTENDING FROM WEIRTON TO 2 MILES SOUTH OF WINTERSVILLE...MOVING SOUTHEAST AT 10 MPH. THIS CLUSTER WILL PRODUCE LOCALLY HEAVY RAINFALL AND POSSIBLY SOME SMALL HAIL. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... WEIRTON... SUN VALLEY... WINTERSVILLE... STEUBENVILLE... COLLIERS... MINGO JUNCTION... FOLLANSBEE... BRILLIANT... WELLSBURG... WINDSOR HEIGHTS... FRANKLIN... BETHANY... 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. 15
Special weather statement, May 24, 12:58 PM EDT, 53 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1258 PM EDT SUN MAY 24 2009 PAZ021-029-241800- ALLEGHENY PA-WASHINGTON PA- 1258 PM EDT SUN MAY 24 2009 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... WASHINGTON AND ALLEGHENY... AT 1256 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED A STRONG THUNDERSTORMS 4 MILES WEST OF MCDONALD...MOVING EAST AT 10 MPH. THIS STORM WILL PRODUCE LOCALLY HEAVY RAINFALL AND POSSIBLY SOME HAIL UP TO DIME SIZE. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... MCDONALD... OAKDALE... 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. 15
Special weather statement, May 24, 1:35 PM EDT, 16 minutes before
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</html>Special weather statement, May 24, 1:46 PM EDT, 5 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 146 PM EDT SUN MAY 24 2009 PAZ020-021-029-WVZ001-241845- ALLEGHENY PA-BEAVER PA-HANCOCK WV-WASHINGTON PA- 146 PM EDT SUN MAY 24 2009 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... WASHINGTON...ALLEGHENY...BEAVER AND HANCOCK... AT 145 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED A STRONG THUNDERSTORM 4 MILES WEST OF HARSHAVILLE...MOVING EAST AT 10 MPH. THIS STORM HAS PRODUCED HAIL UP TO DIME SIZE AND IN SUFFICIENT QUANTITY TO BLANKET THE GROUND. AN INCH OF RAINFALL MAY ALSO BE EXPECTED. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... RACCOON CREEK STATE PARK... HARSHAVILLE... 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. 15
The office that day
Everything else NWS Pittsburgh, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 2:27 PM EDT | Severe Thunderstorm Warning | PBZ | Allegheny, Westmoreland | 33 min |
| May 24, 3:35 PM EDT | Severe Thunderstorm Warning | PBZ | Armstrong, Indiana | 40 min |
| May 24, 4:43 PM EDT | Flash Flood Warning | PBZ | Fayette, Greene | 3 hr |
| May 24, 3:51 PM EDT | Severe Thunderstorm Warning | PBZ | Coshocton | 54 min |
| May 24, 6:17 PM EDT | Areal Flood Advisory | PBZ | Belmont, Guernsey, Harrison | 3 hr |
| May 24, 6:32 PM EDT | Areal Flood Advisory | PBZ | Monroe, Noble | 3 hr |
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.