An occluded front coupled with shortwave energy moving through associated with a vigorous upper low over the Great Lakes, combined to produce thunderstorms with heavy rain and flash flooding over northern portions of the Lower Hudson Valley. Training of thunderstorms over extreme eastern Suffolk county resulted in very heavy rain and flash flooding.
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 OKX wrote it up.
An occluded front coupled with shortwave energy moving through associated with a vigorous upper low over the Great Lakes, combined to produce thunderstorms with heavy rain and flash flooding over northern portions of the Lower Hudson Valley. Training of thunderstorms over extreme eastern Suffolk county resulted in very heavy rain and flash flooding.
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 New York, NY wrote its last area forecast discussion before the first event at Jul 1, 12:49 PM EST, 1 hour 11 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 149 PM EDT WED JUL 1 2009 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY NIGHT AS LOW PRESSURE SLOWLY SPINS EAST FROM THE GREAT LAKES REGION. HIGH PRESSURE BUILDS TOWARD THE AREA FOR THE HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CLOSED UPPER LOW AND SURFACE LOW REMAIN NEARLY STATIONARY AGAIN TODAY AS MID LEVEL SHORTWAVES ROTATE THROUGH THE UPPER LOW. ONE SUCH WAVE WAS ROTATING UP INTO EASTERN PA AND DELMARVA...WITH NUMEROUS SHOWERS/TSTMS ALREADY HAVING FIRED UP OUT AHEAD ACROSS LONG ISLAND AND EASTERN CT. TRAINING OF STORMS AND FLASH FLOODING HAVE OCCURRED IN NEW LONDON COUNTY CT...ALONG WITH ISOLATED SVR REPORTS. LINE MOVING UP INTO LONG ISLAND AND SW CT ATTM IS CAPABLE OF PRODUCING HEAVY RAINFALL OF UP TO AN 1-1.25 INCHES PER HOUR...AND MOST OF THE LINE SHOULD PROGRESS ACROSS CT/LONG ISLAND WITH ONLY MINOR URBAN/SMALL STREAM FLOODING EXPECTED...BUT THIS LINE SHOULD EXACERBATE FLOODING ALREADY OCCURRING ACROSS SE CT. FARTHER WEST...MID LEVEL DRYING BEHIND THIS SHORTWAVE SHOULD ALLOW FOR SOME PARTIAL SUNSHINE IN NYC METRO AND THE LOWER HUDSON VALLEY....ALLOWING TEMPS TO RISE WELL INTO THE 70S AND LOWER 80S. SCATTERED TO NUMEROUS SHOWERS/TSTMS SHOULD DEVELOP AS CONVECTIVE TEMPS ARE ACHIEVED PER ALY/OKX/APG 12Z SOUNDINGS...WITH WEAK SFC TROUGH OVER THE AREA SERVING AS FOCUS FOR DEVELOPMENT. STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN...ALSO ISOLATED DAMAGING WINDS AND LARGE HAIL GIVEN PW NEAR 1.5 INCHES AND MBE VECTORS AROUND 10 KT...MLCAPE 1500 J/KG WITH STEEPENING LOW LEVEL LAPSE RATES...AND -10C TO -30C CAPE OF UP TO 500 J/KG. ACTIVITY MAY BECOME ORGANIZED TOWARD EVENING AHEAD OF ANOTHER MID LEVEL IMPULSE MOVING OUT OF WEST VIRGINIA TOWARD ERN PA...WHICH MAY EVENTUALLY REQUIRE A SEVERE TSTM WATCH FOR PORTIONS OF THE AREA PER EARLIER SPC MESOSCALE DISCUSSION. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... LATE TONIGHT UPPER LOW BEGINS TO SLOWLY FILL AND DRIFT TO THE NORTHEAST. WITH AREAS OF VORTICITY ROTATING THROUGH WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS. UPPER LOW CONTINUES TO OPEN AND DRIFT TO THE NORTHEAST THURSDAY INTO THURSDAY NIGHT. MAINLY DIURNALLY DRIVEN CONVECTION AGAIN THURSDAY. FRIDAY INTO FRIDAY NIGHT TROUGH AXIS LIFTS TO THE NORTHEAST WITH RISING HEIGHTS ACROSS THE AREA. THREAT OF SHOWERS AND THUNDERSTORMS SLOWLY DIMINISHES AS UPPER LOW LIFTS AND SURFACE LOW MOVES INTO EASTERN CANADA AND NORTHERN NEW ENGLAND...WEAK COLD FRONTAL PASSAGE LATE FRIDAY INTO FRIDAY NIGHT WITH THE LOW. LEANED TOWARD A FASTER LIFTING OF THE UPPER LOW AS THE ECMWF AND GFS DO...RATHER THAN THE SLOWER NAM WHICH MOVE TROUGH AXIS THROUGH TOWARD 12Z SATURDAY. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... UPPER LOW REMAINS OVER THE NORTHEAST THROUGH FRIDAY BEFORE MOVING OUT OF THE REGION ON SATURDAY. A SERIES OF WEAK SHORT WAVES AND WEAK COLD FRONTS/SURFACE TROUGHS WILL BRING A THREAT OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA...WITH THE HIGHER CHANCES DURING THE AFTERNOON AND EVENING HOURS. POPS LOWER EARLY NEXT WEEK. LIKELY A DRY DAY ON SATURDAY WITH TEMPERATURES INTO THE LOWER TO MID 80S...EXCEPT MID TO UPPER 70S ALONG COASTAL AREAS. SLIGHT CHC POPS FOR SUNDAY WITH A WEAK SHORT WAVE...THEN SHOWERS AGAIN ON MONDAY WITH ANOTHER SHORT WAVE MOVING IN. DRY DAY ON TUESDAY AS BUILDS ACROSS FROM THE MID ATLANTIC STATES. TEMPS IN THE LONG TERM NEAR NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... RW/TRW SHALL CONTINUE TO MOVE ACROSS GON THE NEXT FEW HRS...OTHERWISE VFR FOR THE BALANCE OF THE AFTN ELSEWHERE. STORMS WILL DEVELOP OVER VA AND ERN PA THIS AFTN AND SLOWLY MOVE NNE THIS EVENING. TOUGH CALL ON TIMING SO DID NOT INCLUDE ANY MENTION OF PCPN IN THE TERMINALS UNTIL STORMS GET ORGANIZED. APPEARS ANY ORGANIZED TSTM CLUSTER SHALL PASS DURING THE NIGHT BASED OFF LATEST SHORT TERM DETERMINISTIC MODELS. LLVL RH INCREASES TNGT ALLOWING MVFR CIGS/VIS TO DEVELOP...HWVR BEST CHANCE OF IFR WX WILL BE ISP AND GON WHICH EXPERIENCED THE HIGHEST AMOUNT OF RAINFALL DURING THE DAY. MVFR CIGS LIFT BY 15Z OR SO TO VFR. OUTLOOK 18Z THURSDAY THROUGH MONDAY/... MVFR WX POSSIBLE IN RW/TRW DURING THE AFTERNOON AND EVENING THURSDAY AND FRIDAY. && .MARINE... LOW PRESSURE CONTINUES TO REMAIN OVER THE GREAT LAKES REGION AND WILL SLOWLY SLIDE EASTWARD THROUGH FRIDAY. A SERIES OF SHORTWAVES WILL PUSH ACROSS THE AREA WATERS AS THE LOW ROTATES. WINDS AND WAVES WILL GENERALLY REMAIN BELOW SCA CONDITIONS THROUGH SATURDAY...ALTHOUGH WNAWAVE HINTING AT THE POSSIBILITY OF 5 FOOTERS THURSDAY AND FRIDAY ON THE EASTERN OCEAN. THERE MAY BE SOME LOCALLY ROUGH SEAS ALONG WITH STRONG WINDS IN THE VICINITY OF AFTERNOON AND EVENING THUNDERSTORMS. && .HYDROLOGY... NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO THIS EVENING MAY PRODUCE HEAVY RAINFALL WITH ONE HALF TO ONE INCH OF RAINFALL...WITH LOCALLY 1 TO 2 INCHES. MINOR URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE. A QUARTER TO A HALF INCH POSSIBLE AGAIN THURSDAY AND THURSDAY NIGHT...WITH LIGHTER AMOUNTS FRIDAY INTO FRIDAY NIGHT. DRY WEATHER RETURNS SATURDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW YORK NY 1256 PM EDT WED JUL 1 2009 ANZ330-335-338-340-345-350-353-355-CTZ005>012-NJZ002>006-011- NYZ067>081-021700- LONG ISLAND SOUND EAST OF NEW HAVEN CT/PORT JEFFERSON NY- LONG ISLAND SOUND WEST OF NEW HAVEN CT/PORT JEFFERSON NY- NEW YORK HARBOR-PECONIC AND GARDINERS BAYS- SOUTH SHORE BAYS FROM JONES INLET THROUGH SHINNECOCK BAY- MORICHES INLET NY TO MONTAUK POINT NY OUT 20 NM- FIRE ISLAND INLET NY TO MORICHES INLET NY OUT 20 NM- SANDY HOOK NJ TO FIRE ISLAND INLET NY OUT 20 NM-NORTHERN FAIRFIELD- NORTHERN NEW HAVEN-NORTHERN MIDDLESEX-NORTHERN NEW LONDON- SOUTHERN FAIRFIELD-SOUTHERN NEW HAVEN-SOUTHERN MIDDLESEX- SOUTHERN NEW LONDON-WESTERN PASSAIC-BERGEN-EASTERN PASSAIC-ESSEX- HUDSON-UNION-ORANGE-PUTNAM-ROCKLAND-NORTHERN WESTCHESTER- SOUTHERN WESTCHESTER-NEW YORK (MANHATTAN)-BRONX- RICHMOND (STATEN ISLAND)-KINGS (BROOKLYN)-QUEENS-NASSAU- NORTHWESTERN SUFFOLK-NORTHEASTERN SUFFOLK-SOUTHWESTERN SUFFOLK- SOUTHEASTERN SUFFOLK- 1256 PM EDT WED JUL 1 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS...SOUTHERN CONNECTICUT...NORTHEAST NEW JERSEY AND SOUTHEAST NEW YORK. .DAY ONE...THIS AFTERNOON AND TONIGHT. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE CAPABLE OF PRODUCING FLOODING RAINS...DAMAGING WIND GUSTS AND LARGE HAIL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ON THURSDAY WILL AGAIN BE CAPABLE OF PRODUCING FLOODING RAINS...DAMAGING WIND GUSTS AND LARGE HAIL. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && THIS HAZARDOUS WEATHER OUTLOOK PROVIDES A SUMMARY OF POTENTIAL WIDESPREAD HAZARDOUS WEATHER EVENTS THAT MAY REACH NWS WARNING CRITERIA. MOST LONG FUSED NWS WATCHES...WARNINGS AND ADVISORIES IN EFFECT ARE HIGHLIGHTED. PLEASE REFER TO THE LATEST NWS FORECASTS FOR WEATHER NOT MEETING NWS WARNING CRITERIA. GOODMAN
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 1215 PM EDT WED JUL 1 2009 NYZ078-080-011700- NORTHWEST SUFFOLK-SOUTHWEST SUFFOLK- 1215 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORM WILL IMPACT SUFFOLK COUNTY... AT 1214 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR ISLIP...AND MOVING NORTHEAST AT 20 MPH. PEOPLE IN SUFFOLK COUNTY...INCLUDING ISLIP...SAYVILLE...RONKONKOMA... HOLBROOK...PATCHOGUE...FARMINGVILLE...CENTEREACH...MEDFORD...CORAM AND YAPHANK...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN. GUSTY WINDS UP TO 50 MPH ARE EXPECTED WITH THIS STORM. IN ADDITION... VERY HEAVY RAIN IS OCCURRING WITH THIS STORM. THIS COULD CAUSE PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF POOR DRAINAGE AREAS. JMC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 1257 PM EDT WED JUL 1 2009 NYZ079-081-011800- NORTHEAST SUFFOLK-SOUTHEAST SUFFOLK- 1257 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORMS WILL IMPACT SUFFOLK COUNTY... AT 1256 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM MASTIC TO 6 MILES SOUTH OF SOUTHAMPTON TO 31 MILES SOUTH OF SOUTHAMPTON. THESE STORMS WILL BE... NEAR CALVERTON BY 105 PM. NEAR RIVERHEAD BY 115 PM. NEAR BRIDGEHAMPTON BY 120 PM. NEAR MATTITUCK BY 125 PM. NEAR SAG HARBOR BY 130 PM. WINDS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS. IN ADDITION...VERY HEAVY RAIN IS OCCURRING WITH THESE STORMS. THIS WILL CAUSE PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF POOR DRAINAGE AREAS. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER IMMEDIATELY. JMC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 126 PM EDT WED JUL 1 2009 CTZ005-NYZ068-011830- NORTHERN FAIRFIELD-PUTNAM- 126 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORM WILL IMPACT EASTERN PUTNAM AND FAIRFIELD COUNTIES... AT 125 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 5 MILES SOUTHWEST OF DANBURY...AND MOVING NORTH AT 10 MPH. PEOPLE IN EASTERN PUTNAM AND FAIRFIELD COUNTIES...INCLUDING DANBURY AND SHERMAN...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN. WINDS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. IN ADDITION...VERY HEAVY RAIN IS OCCURRING WITH THIS STORM. THIS COULD CAUSE PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF POOR DRAINAGE AREAS. JMC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 139 PM EDT WED JUL 1 2009 NYZ067-011845- ORANGE- 139 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORM WILL IMPACT WESTERN ORANGE COUNTY... AT 137 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A SEVERE THUNDERSTORM 8 MILES SOUTHWEST OF GLEN SPEY...OR 10 MILES NORTHWEST OF MILFORD...AND MOVING EAST AT 10 MPH. ALTHOUGH THE STORM APPEARS TO BE WEAKENING SLIGHTLY AT THIS TIME...PEOPLE IN WESTERN ORANGE COUNTY...INCLUDING PORT JERVIS...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN. JMC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 148 PM EDT WED JUL 1 2009 CTZ008-012-NYZ079-011845- NORTHEAST SUFFOLK-NORTHERN NEW LONDON-SOUTHERN NEW LONDON- 148 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORMS CONTINUING TO IMPACT NEW LONDON AND SUFFOLK COUNTIES... AT 147 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 7 MILES NORTHEAST OF GARDNERS ISLAND TO WESTBROOK...MOVING NORTHEAST AT 30 MPH. INTENSE CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS. IN ADDITION...VERY HEAVY RAIN...WITH RAINFALL RATES OF UP TO 2 INCHES AN HOUR...IS OCCURRING WITH THESE STORMS. THIS COULD CAUSE PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF POOR DRAINAGE AREAS. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER IMMEDIATELY. NV
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 212 PM EDT WED JUL 1 2009 CTZ005-011845- NORTHERN FAIRFIELD- 212 PM EDT WED JUL 1 2009 ...STRONG THUNDERSTORM WILL IMPACT NORTHERN FAIRFIELD COUNTY... AT 211 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR SHERMAN...AND MOVING NORTH AT 15 MPH. THIS STORM WILL BE... NEAR SHERMAN BY 225 PM. SMALL HAIL...AND GUSTY WINDS UP TO 50 MPH ARE EXPECTED WITH THIS STORM. IN ADDITION...VERY HEAVY RAIN IS OCCURRING WITH THIS STORM. THIS COULD CAUSE PONDING OF WATER ON ROADWAYS...AND MINOR FLOODING OF POOR DRAINAGE AREAS. JMC
The Brookhaven radar (KOKX), 94 km away, was scanning. The volume nearest the first event began at 19:00 UTC.
2 flash flood. Local standard time, as filed.
Several roads were closed on Fishers Island due to flooding.
Several streams exceeded bankfull in Cornwall-On-Hudson. Basement flooding also occurred on Oak Tree Dr. and Minehill Rd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2009Every state in 2009This day in weather historyWarnings in New York, July 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: 188947, 188949.