A cold front over the Great Lakes moved into northern Pennsylvania late in the day. Scattered showers and thunderstorms developed, which produced isolated areas of heavy rain and minor flood problems.
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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 BGM wrote it up.
A cold front over the Great Lakes moved into northern Pennsylvania late in the day. Scattered showers and thunderstorms developed, which produced isolated areas of heavy rain and minor flood problems.
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 Binghamton, NY wrote its last area forecast discussion before the first event at Aug 19, 12:59 PM EST, 1 minute earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 159 PM EDT WED AUG 19 2009 .SYNOPSIS... A COLD FRONT WILL MOVE INTO NORTHERN PENNSYLVANIA BY THIS EVENING ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS. THIS FRONT WILL WORK BACK NORTH AS A WARM FRONT ON THURSDAY. UNSETTLED WEATHER IS EXPECTED ON THURSDAY AND FRIDAY WITH WARM AND HUMID CONDITIONS SUPPORTING THE DEVELOPMENT OF MORE SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 14Z HAND DRAWN SFC ANALYSIS SHOWS COLD FRONT BISECTING CNTRL NY WITH DWPTS STARTING TO DROP FROM WRN TO N CNTRL NY. FRONT IS MOVING SLOWLY AND EXPECT IT WILL STALL OUT ACROSS NEPA THIS AFTERNOON. PLENTY OF LAYERED CLOUDS AROUND THE REGION THIS MORNING...BUT EXPECT WE WILL STILL DESTABILIZE SUFFICIENTLY FOR SCT SHRA/TSRA TO DEVELOP THIS AFTERNOON WITH THE FOCUS ALONG AND AHEAD OF THE FRONT...MAINLY IN NEPA. THIS IS VERY SIMILAR TO PREV FCST...BUT WITH SLIGHTLY MORE INSTABILITY EXPECTED I HAVE UPPED POPS A BIT FOR THE AFTERNOON. SOME ISOLATED ACTIVITY IS ALSO EXPECTED IN NY NEAR THE BORDER COUNTIES WITH EVEN LESS ACTIVITY FURTHER NORTH. NO CHANGES TO TEMPERATURES OR OTHER PARAMETERS. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... WITH THE FRONT MOVING THROUGH THE CWA OVER NIGHT AND THE LOSS OF DAYTIME HEATING...ACTIVITY WILL BE QUELLED FROM THE NORTHWEST TO THE SOUTHEAST THROUGH THE NIGHT TIME HOURS. HOWEVER...THE FRONT LOOKS TO STALL ALONG THE SOUTHERN BOUNDARY OF THE CWA. THIS WOULD MOST LIKELY KEEP ENOUGH INSTABILITY IN THAT AREA TO CONTINUE RAIN SHOWERS AND PERHAPS SOME THUNDERSTORM DEVELOPMENT. BY THURSDAY...THE FRONT LIFTS BACK OUT AS A WARM FRONT. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO THE CWA AND POSSIBLE SOME THUNDERSTORMS. THEN BY FRIDAY MORNING...YET ANOTHER LOW PRESSURE SYSTEM MAKES ITS WAY TOWARDS THE CWA AND ANOTHER COLD FRONT YET PUSHES THROUGH. THIS WILL BRING MORE SHOWERS AND THUNDERSTORMS FOR SATURDAY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... WE WILL START OFF THE LONG TERM PERIOD WITH A COLD FRONT MOVING ACROSS THE AREA. AS THE PREVIOUS FORECASTER MENTIONED...HIGH PWATS ON BOTH THE EURO AND GFS SUGGEST THE POTENTIAL FOR HEAVY RAIN FRIDAY NIGHT. LIKELY POPS DURING THIS TIME LOOK GOOD. UPDATED THE FORECAST TO REFLECT MORE OPTIMISM FOR SATURDAY...ESPECIALLY WEST OF I-81. BOTH THE 12Z EURO AND 0Z GFS ARE IN FAIRLY GOOD AGREEMENT WITH THE POSITION OF BILL WELL OFF THE COAST...A COLD FRONT JUST TO OUR EAST...AND AN UPPER TROF DIGGING ACROSS THE GREAT LAKES. IF THE MODELS ARE ACCURATE AND TIMING DIFFERENCES DO NOT POP UP...THIS WOULD PUT US IN THE DRY SECTOR BEHIND THE FRONT...AND AHEAD OF MOISTURE WITH THE UPPER TROF BACK TO OUR WEST. INCREASED SUBSIDENCE MAY OCCUR DEPENDING ON THE EXACT TRACK OF BILL. JUST GLANCED AT THE NEW 0Z EURO AND IT STILL SHOWS US IN THE SWEET SPOT SATURDAY...BETWEEN TWO SYSTEMS AND DRY. THE EXCEPTION TO THIS IS ACROSS THE FAR EAST DUE TO THE PROXIMITY OF THE SLOWING COLD FRONT. CHANCE POPS ARE ALREADY IN THESE AREAS SO THAT SHOULD COVER IT. WHATEVER HAPPENS ON SATURDAY...THE UPPER TROF MENTIONED ABOVE WILL MOVE INTO WESTERN NY BY SUNDAY AFTERNOON. WITH THE POSITION OF THE UPPER TROF JUST TO OUR WEST...FELT AT LEAST LOW END SHOWER CHANCES WERE WARRANTED. UPPER TROF MOVES OVERHEAD MONDAY WITH MORE PRECIPITATION CHANCES BEFORE LIFTING OUT. TEMPS WILL COOL TO SEASONAL NORMS FOR THIS TIME OF THE YEAR. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... SFC TROF DROPPING INTO NRN PA AT 18Z. CONVECTION WILL BE LIMITED TO KAVP TERMINAL WITH MVFR THUNDERSTORMS POSSIBLE THROUGH LATE AFTERNOON. FRONTAL BOUNDARY WILL DROP SOUTH OF ALL TERMINALS BY THIS EVENING THEN RETURN BACK AS WARM FRONT LATE TONIGHT AND THURSDAY. MID CLOUDS WILL INCREASE LATE TONIGHT WITH MVFR FOG POSSIBLE AT KITH/KELM/KBGM/KAVP BTW 09Z-13Z. DENSE FOG NOT EXPECTED DUE TO BOUNDARY LAYER MIXING AND INCREASING CLOUDS. ON THURSDAY, CLOUD DECK AROUND 4K FT WILL OVERSPREAD TERMINALS BY MID MORNING WITH MVFR SHOWERS POSSIBLE AT KAVP BTW 14Z-18Z. CB MENTIONED IN CLOUD GROUP TO IMPLY POTENTIAL FOR TSRA. WESTERLY WINDS THIS AFTERNOON 5-8 KNOTS BECOMING LIGHT OVERNIGHT THEN S/SE THURSDAY AROUND 10 KNOTS. OUTLOOK... THURSDAY AFTERNOON...MVFR/IFR IN SCATTERED SHOWERS/THUNDERSTORMS. FRIDAY...MVFR/IFR IN SCATTERED SHOWERS/THUNDERSTORMS. SAT...POSSIBLE BRIEF RESTRICTIONS IN SHRA/TSRA. SUN/MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && SYNOPSIS...SLI NEAR TERM...JAB SHORT TERM...SLI LONG TERM...EMH AVIATION...RRM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BINGHAMTON NY 117 PM EDT WED AUG 19 2009 NYZ009-015>018-022>025-036-037-044>046-055-056-201730- NORTHERN ONEIDA-YATES-SENECA-SOUTHERN CAYUGA-ONONDAGA-STEUBEN- SCHUYLER-CHEMUNG-TOMPKINS-MADISON-SOUTHERN ONEIDA-CORTLAND-CHENANGO- OTSEGO-TIOGA-BROOME- 117 PM EDT WED AUG 19 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW YORK. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. HEAVY RAINFALL MAY DEVELOP FROM FRIDAY INTO SATURDAY MORNING AS A COLD FRONT SLOWLY MOVES THROUGH THE REGION. THE POTENTIAL FOR FLOODING WILL HAVE TO BE MONITORED DURING THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. NYZ057-062-PAZ038>040-043-044-047-048-072-201730- DELAWARE-SULLIVAN-BRADFORD-SUSQUEHANNA-NORTHERN WAYNE-WYOMING- LACKAWANNA-LUZERNE-PIKE-SOUTHERN WAYNE- 117 PM EDT WED AUG 19 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW YORK...SOUTHEASTERN NEW YORK AND NORTHEAST PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. SCATTERED THUNDERSTORMS THIS AFTERNOON WILL PRODUCE TORRENTIAL RAINFALL AND MAY LEAD TO LOCALIZED MINOR FLOODING...ESPECIALLY IN TYPICAL LOW LYING AREAS AND ALONG TOWN AND VILLAGE STREETS. THERE IS ALSO A SLIGHT RISK OF SEVERE WEATHER IN THE AREA THIS AFTERNOON. SOME THUNDERSTORMS MAY BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS IN ADDITION TO HEAVY RAIN. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. HEAVY RAINFALL MAY DEVELOP FROM FRIDAY INTO SATURDAY MORNING AS A COLD FRONT SLOWLY MOVES THROUGH THE REGION. THE POTENTIAL FOR FLOODING WILL HAVE TO BE MONITORED DURING THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THROUGH EARLY EVENING.
The Binghamton radar (KBGM), 94 km away, was scanning. The volume nearest the first event began at 17:58 UTC.
1 flash flood. Local standard time, as filed.
A few roads were flooded in Old Forge and Moosic.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2009Every state in 2009This day in weather historyWarnings in Pennsylvania, August 2009
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: 194117.