While a slow moving cold front eased south across southern Ontario, a 30-mile wide band of showers and thunderstorms developed over Western New York. Initially the thunderstorms produced heavy rains.
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 BUF wrote it up.
While a slow moving cold front eased south across southern Ontario, a 30-mile wide band of showers and thunderstorms developed over Western New York. Initially the thunderstorms produced heavy rains. Over parts of Genesee county, two to three inches of rain fell in less than two hours. Roads were reported flooded and closed in Batavia, LeRoy and Stafford. In Batavia, about three dozen basements flooded, however none of the flood waters reached the first floor. In one home a twenty-foot section of the foundation collapsed. The thunderstorms continued to strengthen as they moved into the southern tier and eastern Lake Ontario Region. Reports of downed trees and wires were scattered throughout the region. Falling trees damaged homes in Savannah and Fairport. Hail, up to three-quarter inch in diameter, was reported with the storms.
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 Buffalo, NY wrote its last area forecast discussion before the first event at Jul 31, 2:35 PM EST, 1 hour 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 335 PM EDT TUE JUL 31 2012 .SYNOPSIS... SCATTERED SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY A COLD FRONT MOVING EAST ACROSS THE EASTERN GREAT LAKES OVERNIGHT. A FEW MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE WEDNESDAY ACROSS THE EASTERN SECTION AS THE FRONT CONTINUES TO CROSS THE STATE. HIGH PRESSURE WILL BRING DRY WEATHER ON THURSDAY BEFORE THE NEXT COLD FRONT BRINGS A CHANCE FOR SHOWERS ON FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... A PRE-FRONTAL LINE OF SHOWERS AND THUNDERSTORMS APPROACHING WESTERN NEW YORK WILL CONTINUE ACROSS THE AREA THIS EVENING AND OVERNIGHT. SHOWERS AND THUNDERSTORMS CONTINUE TO FIRE FROM THE FINGER LAKES WEST. THIS ACTIVITY IS EXPECTED TO EXPAND INTO THE REST OF THE CWA OVER THE NEXT SEVERAL HOURS. ONCE AGAIN IT LOOKS LIKE THE IMMEDIATE BUFFALO METRO AREA WILL BE SHADOWED BY THE LAKE WITH LIMITED ACTIVITY HERE ONCE THE LAKE BREEZE EASES AFTER SUNSET. LAKE BREEZES AND OUTFLOW BOUNDARIES WILL BE THE TRIGGERS FOR A LOT OF THE ACTIVITY THIS AFTERNOON/EVENING. GIVEN THE LOW SHEAR ENVIRONMENT, AM NOT EXPECTING TO SEE A WHOLE IN THE WAY OF SEVERE ACTIVITY WITH THESE PULSE STORMS. RAINFALL RATES OF UP TO AN INCH AND A HALF AN HOUR COULD RESULT IS SOME LOCALIZED FLOODING ISSUES. TROUGH AXIS WILL MOVE SLOWLY ACROSS THE REGION WEDNESDAY. WHILE FORCING IS RELATIVELY WEAK OVER WESTERN PORTIONS...IT MAY BE ENOUGH TO FIRE SCATTERED SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT THUS THE BEST CHANCE OF CONVECTION REMAINS OVER THE EASTERN SECTIONS DURING THE AFTERNOON. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/... WEDNESDAY NIGHT AND THURSDAY A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER LAKES WITH CLEARING SKIES. THE AIRMASS BEHIND THIS WEAK COLD FRONT IS ONLY SLIGHTLY COOLER AND DRIER...SO LOWS WILL NOT DROP OUT OF THE MID 60S ON THE LAKE PLAINS WITH MID TO UPPER 50S ACROSS THE INTERIOR SOUTHERN TIER AND TUG HILL REGION. ON THURSDAY SUNSHINE AND 850MB TEMPS OF ABOUT +16C WILL BRING ANOTHER DAY OF ABOVE AVERAGE TEMPERATURES WITH MID TO UPPER 80S ACROSS LOWER ELEVATIONS INLAND FROM THE LAKES. THE LIGHT SYNOPTIC SCALE FLOW AND STRONG DIFFERENTIAL HEATING WILL SUPPORT AFTERNOON LAKE BREEZES WITH COOLER TEMPS ALONG BOTH LAKESHORES. THURSDAY NIGHT AND FRIDAY A VERY WEAK COLD FRONT WILL DROP SOUTH ACROSS THE LOWER LAKES. ALL OF THE MID LEVEL FORCING WILL REMAIN WELL NORTH OF THE BORDER...WITH THE LOW LEVEL BOUNDARY ESSENTIALLY WASHING OUT BY FRIDAY OVER NY OR PA. THIS MAY PRODUCE JUST ENOUGH LOW LEVEL CONVERGENCE TO SUPPORT A FEW WIDELY SCATTERED SHOWERS AND THUNDERSTORMS...BUT COVERAGE IS EXPECTED TO REMAIN VERY SPARSE. WITH THIS IN MIND WILL JUST MAINTAIN LOW CHANCE POPS FOR THE FRONTAL PASSAGE FROM LATE THURSDAY NIGHT THROUGH FRIDAY. DESPITE THE WEAK APPROACHING COLD FRONT...850MB TEMPS OF AROUND +16C WILL STILL SUPPORT HIGHS IN THE MID TO UPPER 80S AWAY FROM THE LAKES. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A ZONAL FLOW WILL REMAIN IN PLACE ACROSS NORTH AMERICA THROUGH THE FIRST PART OF THE WEEKEND WITH A DOMINANT HOT RIDGE IN PLACE ACROSS THE SOUTHERN 2/3 OF THE NATION. BY SUNDAY A MORE SIGNIFICANT SHORTWAVE WILL AMPLIFY THE PATTERN TEMPORARILY WITH A TROUGH DIGGING THROUGH THE GREAT LAKES. LOOKING AT THE DETAILS...ON SATURDAY MODEL GUIDANCE CONTINUES TO DEVELOP DEEP SOUTHERLY FLOW AROUND THE WESTERN PERIPHERY OF THE BERMUDA HIGH. SOME MEDIUM RANGE MODELS...MOST NOTABLY THE GFS STILL ATTEMPT TO DEVELOP WIDELY SCATTERED DIURNAL CONVECTION AS DEEPER MOISTURE DRAWS NORTH INTO THE REGION. WILL MAINTAIN A LOW CHANCE POP FOR THIS ON SATURDAY. BY SUNDAY THE MORE SIGNIFICANT TROUGH WILL BEGIN TO DIG THROUGH THE GREAT LAKES WITH HEIGHT FALLS SUPPORTING LARGE SCALE ASCENT. THIS WILL BRING A BETTER CHANCE OF MORE ORGANIZED SHOWERS AND STORMS FROM SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. BY MONDAY THE GFS AND ECMWF PULL THIS SYSTEM TO THE EAST COAST WITH A RETURN TO DRY WEATHER AND SEASONABLE TEMPS AS THE ZONAL FLOW BRIEFLY AMPLIFIES AND ALLOWS COOLER CANADIAN AIR TO NOSE INTO THE GREAT LAKES. DRY WEATHER WILL LAST THROUGH TUESDAY AS SURFACE HIGH PRESSURE BUILDS OVER THE LOWER LAKES. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... A PRE-FRONTAL LINE OF SHRA/TSRA IS APPROACHING WNY AND WILL CROSS THE NIAGARA FRONTIER WITHIN THE NEXT FEW HOURS. WELL AHEAD OF THE AT LINE SCT SHWRS/TSTMS CONTINUE TO FIRE ACROSS NRN PA...THE FINGER LAKES AND NORTH COUNTRY IN A VERY UNSTABLE AFTN AIR MASS. PREFRONTAL LINE WILL CONTINUE TO MOVE ACROSS THE REGION THROUGH THE EVENING AND EARLY OVERNIGHT HOURS WITH DIMINISHING INTENSITY AFT SUNSET. EXPECT MAINLY VFR CONDITIONS TO PREVAIL...BUT ANY PASSING THUNDERSTORMS COULD LOWER CIGS/VSBYS TO MVFR AT TIMES. LATE TONIGHT/EARLY WEDNESDAY AREAS OF MVFR VSBY AS LOCAL FOG DEVELOPS. VSBYS RETURN TO VFR BY 12Z AS FOG BURNS OFF. OUTLOOK... THURSDAY...VFR. FRIDAY AND SATURDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. SATURDAY...VFR/MVFR CHANCE OF SHOWERS/THUNDERSTORMS. && .MARINE... A COLD FRONT WILL CROSS THE LOWER LAKES THIS EVENING AND OVERNIGHT. SHOWERS AND THUNDERSTORMS PRECEDE AND ACCOMPANY THE FRONT. WINDS WILL SHIFT FROM SOUTHWEST TO NORTHWEST WITH THE PASSAGE OF THE FRONT. OUTSIDE OF THUNDERSTORMS...WIND AND WAVE ACTION WILL REMAIN LOW THROUGH THE END OF THE WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && SYNOPSIS...LEVAN NEAR TERM...LEVAN SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...LEVAN MARINE...LEVAN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BUFFALO NY 519 AM EDT TUE JUL 31 2012 NYZ001>008-010>014-019>021-085-010930- NIAGARA-ORLEANS-MONROE-WAYNE-NORTHERN CAYUGA-OSWEGO-JEFFERSON-LEWIS- NORTHERN ERIE-GENESEE-WYOMING-LIVINGSTON-ONTARIO-CHAUTAUQUA- CATTARAUGUS-ALLEGANY-SOUTHERN ERIE- 519 AM EDT TUE JUL 31 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND NORTH CENTRAL NEW YORK. .DAY ONE...TODAY AND TONIGHT. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES... AND STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN BUFFALO CAN BE FOUND ON THE INTERNET AT HTTP://WWW.WEATHER.GOV/BUF LEZ020-040-041-LOZ030-042>045-062>065-SLZ022-024-010930- UPPER NIAGARA RIVER AND BUFFALO HARBOR- LAKE ERIE NEARSHORE WATERS FROM RIPLEY TO DUNKIRK- LAKE ERIE NEARSHORE WATERS FROM DUNKIRK TO BUFFALO- LOWER NIAGARA RIVER- LAKE ONTARIO NEARSHORE WATERS FROM THE NIAGARA RIVER TO HAMLIN BEACH- LAKE ONTARIO NEARSHORE WATERS FROM HAMLIN BEACH TO SODUS BAY- LAKE ONTARIO NEARSHORE WATERS FROM SODUS BAY TO MEXICO BAY- LAKE ONTARIO NEARSHORE WATERS FROM MEXICO BAY TO THE SAINT LAWRENCE RIVER- LAKE ONTARIO OPEN WATERS FROM THE NIAGARA RIVER TO HAMLIN BEACH- LAKE ONTARIO OPEN WATERS FROM HAMLIN BEACH TO SODUS BAY- LAKE ONTARIO OPEN WATERS FROM SODUS BAY TO MEXICO BAY- LAKE ONTARIO OPEN WATERS FROM MEXICO BAY TO THE SAINT LAWRENCE RIVER- SAINT LAWRENCE RIVER FROM CAPE VINCENT TO OGDENSBURG- SAINT LAWRENCE RIVER FROM OGDENSBURG TO SAINT REGIS- 519 AM EDT TUE JUL 31 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEW YORK WATERS OF LAKE ERIE...LAKE ONTARIO...AND THE SAINT LAWRENCE RIVER. .DAY ONE...TODAY AND TONIGHT. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES... AND STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN BUFFALO CAN BE FOUND ON THE INTERNET AT HTTP://WWW.WEATHER.GOV/BUF
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BUFFALO NY
329 PM EDT TUE JUL 31 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0315 PM HAIL WARSAW 42.74N 78.13W
07/31/2012 M1.00 INCH WYOMING NY EMERGENCY MNGR
EMERGENCY MANAGER REPORTED DIME AND QUARTER SIZED HAIL.
&&
EVENT NUMBER BUF1200212
ARSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BUFFALO NY 334 PM EDT TUE JUL 31 2012 NYZ011>013-019>021-085-312100- GENESEE-WYOMING-LIVINGSTON-CHAUTAUQUA-CATTARAUGUS-ALLEGANY- SOUTHERN ERIE- INCLUDING THE CITIES OF...BATAVIA...WARSAW...GENESEO... JAMESTOWN...OLEAN...WELLSVILLE...ORCHARD PARK...SPRINGVILLE 334 PM EDT TUE JUL 31 2012 ...STRONG THUNDERSTORMS DEVELOPING ACROSS THE AREA THIS AFTERNOON... STRONG THUNDERSTORMS MOVING ACROSS THE REGION WILL BE CAPABLE OF PRODUCING UP TO PENNY SIZED HAIL...AND STRONG GUSTY WINDS TO 40 MPH. FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH SOME OF THESE STORMS. MOVE INDOORS IMMEDIATELY. THESE STORMS HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAIN IN A SHORT AMOUNT OF TIME...AND COULD CAUSE LOCALIZED FLOODING OF ROADS AND POOR DRAINAGE AREAS. JM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BUFFALO NY 357 PM EDT TUE JUL 31 2012 NYZ003-004-014-312100- MONROE-WAYNE-ONTARIO- INCLUDING THE CITIES OF...ROCHESTER...NEWARK...CANANDAIGUA 357 PM EDT TUE JUL 31 2012 ...STRONG THUNDERSTORMS WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON INTO THIS EVENING... NUMEROUS STRONG THUNDERSTORMS ARE MOVING TO THE EAST AND NORTHEAST AT 20 MPH. THESE STORMS WILL BE CAPABLE OF PRODUCING VERY HEAVY RAIN...FREQUENT LIGHTNING...DIME SIZED HAIL AND STRONG GUSTY WINDS UP TO 40 MPH. LOCALLY HEAVY RAINFALL WITH THESE STORMS WILL QUICKLY CREATE PONDING OF WATER ACROSS AREA ROADWAYS AND ALSO REDUCE VISIBILITIES MAKE DRIVING DIFFICULT FOR MOTORISTS. RAINFALL AMOUNTS OF UP TO HALF AN INCH OR MORE IN SOME LOCATIONS WILL BE POSSIBLE THROUGH 5 PM.
The Buffalo radar (KBUF), 121 km away, was scanning. The volume nearest the first event began at 20:58 UTC.
12 thunderstorm wind, 3 flash flood, 1 hail. Local standard time, as filed.
A trained spotter reported numerous trees and wires down.
A trained spotter reported a tree fell on a house.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down. Power poles were snapped.
A trained spotter reported a tree down on a house.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
Law enforcement reported numerous trees and wires down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2012Every state in 2012This day in weather historyWarnings in New York, July 2012
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: 405227, 405230, 405232, 405233, 405234, 405235, 405238, 405242, 405243, 405244, 405246, 405247, 405248, 405249, 405250, 405252.