A slow-moving upper level disturbance and associated cold air aloft combined with marginal surface based instability/weak trough to produce scattered severe thunderstorms.
Every event with a place to put it. 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 CTP wrote it up.
A slow-moving upper level disturbance and associated cold air aloft combined with marginal surface based instability/weak trough to produce scattered severe thunderstorms.
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 State College, PA wrote its last area forecast discussion before the first event at Jul 26, 12:22 PM EST, 1 hour 18 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 122 PM EDT THU JUL 26 2007 .SYNOPSIS... THE UPPER LEVEL...CUTOFF LOW NEAR KTOL WILL DRIFT SLOWLY NORTHWEST INTO THE LOWER PENINSULA OF MICHIGAN THIS AFT. THIS SYSTEM WILL LIFT EASTWARD ACROSS THE EASTERN LAKES ON FRIDAY...DRAGGING A COLD FRONT INTO THE STATE...BUT THE FRONT IS EXPECTED TO STALL ACROSS THE REGION THIS WEEKEND...KEEPING A THREAT OF SHOWERS AND STORMS ACROSS THE REGION INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... INTERESTING VISIBLE SATELLITE PICTURE EARLIER...WTIH ENHANCE CONVECTION OFF THE COAST...SHOWERS ALONG THE MTS...AND MORE WIDESPEAD ACTION OVER THE LAKES WITH THE CUTOFF LOW. DID UP POPS MORE ACROSS THE SE THIS AFTERNOON AND EVENING...WHERE A FEW CELLS ARE POPPING UP...IN AREA OF HIGHER DEWPOINTS. DID LOWER POPS FROM WHAT WE HAD TO CHC POPS TO THE N AND WE...GIVEN A LOT OF CLDS...AND THAT THE MAIN UPPER LEVEL LOW IS DRIFTING NW...AWAY FROM OUR AREA. ALSO DEWPOINTS LOWER TO THE NW. MAIN CONCERN IS UPSLOPE SE FLOW. ALREADY HAVE REPEAT CELLS COMING OFF MTS OF NW ADAMS CO. && .SHORT TERM /11 PM THIS EVENING THROUGH 6 PM FRIDAY/... DID UP POPS A LITTLE FOR LATE TONIGHT...ALONG WITH AN INCREASE IN MIN TEMPS. ALSO DID BRING TEMPS UP ON FRIDAY...BUT LEFT POPS AS IS...THEY LOOK GOOD. LOOKS LIKE A LITTLE BETTER CHC FOR SHOWERS AND STORMS ON FRIDAY...AS FRONT NEARS. STILL THE BEST CHC OF WIDESPREAD CONVECTION LOOKS LIKE IT WILL DROP SOUTH OF OUR AREA LATER FRIDAY INTO THE WEEKEND...BUT THAT IS A WAYS OUT. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE LONG-WAVE TROF OVER EASTERN NORTH AMERICA WILL MOVE ONLY SLIGHTLY TO THE EAST THIS WEEKEND. THIS TROUGHINESS WILL LINGER OVER EASTERN NORTH AMERICA INTO THE MIDDLE OF NEXT WEEK...AS ALL THE FAST WESTERLY FLOW STAYS WELL NORTH OF PA. THE WEAK PUSH OF THE UPPER FLOW...AND THE RATHER MEAGER SURFACE ANTICYCLONE BEHIND THIS FRONT MAY NOT BE ENOUGH TO MOVE THE SURFACE FRONT SUFFICIENTLY FAR AWAY FROM THE LOCAL AREA. THE FRONT SHOULD ALREADY HAVE A WAVE OR TWO ALONG IT AS IT NEARS PA ON SATURDAY. WILL THEREFORE KEEP THE WEEKEND FILLED WITH CHANCE POPS. MONDAY OR TUESDAY COULD SHOW IMPROVEMENT IF THE HIGH CAN NUDGE IN. SOME OF THE GEFS MEMBERS HAVE STARTED TO HINT AT ANOTHER CUTOFF LOW PINCHING OFF...THIS TIME OVER THE GULF COAST STATES...DURING THE MIDDLE OF NEXT WEEK. THIS POSITION WOULD NOT IMPACT OUR LOCAL AREA QUITE AS MUCH AS THE CURRENT CUTOFF IS. IN GENERAL THE LARGE-SCALE PATTERN LOOKS LIKE IT HAS FOR THE LAST FEW WEEKS WITH A BIG RIDGE OVER THE WEST AND PLAINS...AND A TROF OVER THE EAST. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... MVFR WILL BE THE RULE INTO THE WEEKEND...GIVEN HZ DURING THE DAY...ALONG WITH A CHC OF SHOWERS AND STORMS...ESPECIALLY DURING THE AFTERNOON HOURS. STILL A CHC OF SHOWERS AND STORMS AT NIGHT...WITH FOG...AND LOWER CIGS. SOME POCKETS OF IFR...MAINLY ACROSS THE HIGHER ELEVATIONS AT NIGHT. POCKETS OF VFR WILL BE LIMITED AT BEST TO A FEW HOURS IN THE AFTERNOON EACH DAY. FRONT STALLS THIS WEEKEND...NOT SEEING ANY WIDESPREAD VFR CONDITIONS BEFORE TUE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...MARTIN NEAR TERM...MARTIN SHORT TERM...MARTIN LONG TERM...DANGELO/TYBURSKI AVIATION...MARTIN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 323 AM EDT THU JUL 26 2007 PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053- 056>059-063>066-270730- 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- 323 AM EDT THU JUL 26 2007 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...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. DANGELO
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE STATE COLLEGE PA 222 PM EDT THU JUL 26 2007 PAZ057-261915- DAUPHIN- 222 PM EDT THU JUL 26 2007 ...STRONG THUNDERSTORMS WILL AFFECT DAUPHIN COUNTY... AT 216 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 15 MILES NORTH OF LINGLESTOWN TO ENOLA...MOVING NORTHEAST AT 25 MPH. WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS. TORRENTIAL RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES. EXPECT INTENSE LIGHTNING FROM THESE STORMS. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. THESE STORMS WILL BE NEAR LYKENS...PROGRESS AROUND 230 PM...SKYLINE VIEW...RUTHERFORD HEIGHTS AROUND 245 PM...HUMMELSTOWN AND CLIFTON AROUND 300 PM. THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...I-81 BETWEEN MILE MARKERS 66 AND 80. THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 322. FORECASTER: MARTIN
The State College radar (KCCX), 104 km away, was scanning. The volume nearest the first event began at 18:39 UTC.
1 thunderstorm wind. Local standard time, as filed.
Trained spotter reported several trees down along Route 147 near Halifax.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2007Every state in 2007This day in weather historyWarnings in Pennsylvania, July 2007
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: 36465.