Strong low pressure moving east across the Ohio Valley produced strong southeast winds across the region. These winds were enhanced by down slope from the higher elevations across western Pennsylvania.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PBZ wrote it up.
Strong low pressure moving east across the Ohio Valley produced strong southeast winds across the region. These winds were enhanced by down slope from the higher elevations across western Pennsylvania.
The local office's own words before the first event, 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 the first event at May 11, 12:47 AM EST, 10 hours 57 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 147 AM EDT SUN MAY 11 2008 .SYNOPSIS... A LARGE AND DEEP STORM SYSTEM WILL MOVE ACROSS THE AREA TONIGHT. THIS WILL BRING A GOOD DOSE OF RAIN TO THE AREA THROUGH MONDAY. DRY WEATHER WILL RETURN ON TUESDAY. && .NEAR TERM /THROUGH TODAY/... A LARGE AND DYNAMICAL SYSTEM WILL MOVE TOWARD THE AREA TODAY. THIS WILL PUSH PLENTY OF RAIN INTO THE AREA INTO THE AFTERNOON HOURS. AGAIN THIS MORNING...SOME TIMING DIFFERENCES WITH MODEL SOLUTIONS. NAM REMAINS THE SLOWEST...WITH GFS AND 21Z SREF SHOWING FASTER EASTWARD MOVEMENT. HAVE GONE WITH THE QUICKER BEGINNING TO RAIN BUT NOT AS FAST AS SREF. ONE CONCERN I HAVE FOR TIMING IS THE CONVECTION OVER THE GULF COAST STATES...WHICH SHOULD HELP TO STRENGTHEN CURRENT EASTERN RIDGE AND SLOW THE PROGRESSION OF RAIN. EXPECT MOST IF NOT ALL OF THE AREA TO BE UNDER THE RAIN SHIELD BY THIS AFTERNOON. LITTLE TO NO INSTABILITY AND WITH UL SYSTEM BEGINNING TO OPEN UP AND MOVE SE WILL LEAVE OUT MENTION OF THUNDER. ALTHOUGH A LINE OF TRW IS POSSIBLE THIS AFTERNOON...RIGHT NEAR THE FRONTAL BOUNDARY...ACROSS THE SOUTH. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ENTIRE SYSTEM SHOWING WINTER STORM CHARACTERISTICS TONIGHT AS ENERGY RAPIDLY TRANSFERS TO THE CHESAPEAKE BAY. SYSTEM OCCLUDES LATE TONIGHT AND EASTWARD MOVEMENT IS SLOWED AS UL PATTERN IS SHOWING BRIEF OMEGA BLOCK. THIS SLOW EXIT WILL KEEP RAIN IN THROUGH MOST OF MONDAY. WITH PLENTY OF CLOUDS...RAIN AND COLD AIR ALOFT...TEMPS WILL BE WELL BELOW NORMAL MONDAY. STRONG RIDGING WILL ENSUE TUESDAY IN RESPONSE TO DEEP SYSTEM OFF THE NE COAST. THIS WILL ALLOW FOR VERY DRY AIR TO MOVE IN TUESDAY. EXPECT PLENTY OF SUNSHINE AND CLOSER TO NORMAL TEMPS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... CHANGES AGAIN TO EXTENDED PERIOD AS LATEST GFS IS NOW SHOWING NO PHASING OF CF AND SFC LOW OVER TX. FRONT PUSHES THROUGH WED NIGHT- THU...BRINGING CHANCE OF RAIN AND THEN MOVES WELL EAST AS LOW DEVELOPS OVER TX. LOW MOVES ALONG STALLED FRONT THU AND FRIDAY... BUT BY THEN...FRONT IS WELL SOUTH OF THE AREA. HAVE NOT MADE DRASTIC CHANGES TO THE EXT...JUST PULLED BACK A BIT ON POPS THU- FRI. IF CURRENT SOLUTION IS RIGHT...MOST OF THE EXT WILL BE RAIN FREE. THE ECMWF IS ALSO SHOWING LESS RAIN CHANCES FOR THE EXT. HIGH PRESSURE MOVES IN FOR THE WEEKEND. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... PREVAILING VFR CONDITIONS INTO UNTIL MID MORNING WHEN MOISTURE WILL INCREASE AHEAD OFF DEEPENING SYSTEM MOVING INTO THE WESTERN OHIO VALLEY BY THIS AFTERNOON. CLOSED LOW ALOFT WILL MOVE ACROSS OHIO VALLEY TONIGHT WITH RAIN SHIELD AND LOWER CIGS LATER THIS AFTERNOON AND TONIGHT BRINGING MVFR CONDITIONS BY LATE DAY. IFR EXPECTED TO DEVELOP OVERNIGHT BUT WILL TRY TO PIN DOWN BETTER TIMING OF THIS FOR 12Z TERMINALS. AS SYSTEM EXITS MONDAY IFR IN THE MORNING SHOULD GRADUALLY IMPROVE TO MVFR DURING THE DAY. RIDGE SURFACE AND ALOFT FOR VFR LATER MONDAY NIGHT INTO EARLY WEDNESDAY. COLD FRONT APPROACHES WEDNESDAY AFTER WITH MVFR POSSIBLE LATE IN SHOWERS. WEAK SURFACE HIGH FOR GENERAL VFR THURSDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 430 AM EDT SUN MAY 11 2008 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029>032-WVZ001>004-012-021>023-041-120830- 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- 430 AM EDT SUN MAY 11 2008 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... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1202 PM EDT SUN MAY 11 2008 OHZ068-111815- NOBLE- INCLUDING THE CITY OF...CALDWELL 1202 PM EDT SUN MAY 11 2008 AT 1145 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS MOVING THROUGH NOBLE COUNTY... EXPECT WIND GUST TO 40 KTS WITH SMALL HAIL AND LIGHTNING.
The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
Emergency management reported large trees and power lines down in Uniontown and Hopwood.
Large trees and power lines were reported down by emergency management across the county.
Emergency management reported multiple trees and power lines down across the county.
Emergency management reported numerous large trees and power lines down across the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2008Every state in 2008This day in weather historyWarnings in Pennsylvania, May 2008
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 90997, 90990, 91017, 91013.