A powerful cold front produced numerous severe thunderstorms across Connecticut, Long Island and the Lower Hudson Valley of New York. Some of the storms were very heavy rain producers, training across the same area, which caused isolated flash flooding on Long Island.
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.
A powerful cold front produced numerous severe thunderstorms across Connecticut, Long Island and the Lower Hudson Valley of New York. Some of the storms were very heavy rain producers, training across the same area, which caused isolated flash flooding on Long Island.
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 7, 12:41 PM EST, 9 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 141 PM EDT TUE JUL 7 2009 .SYNOPSIS... A LOW PRESSURE TROUGH WILL REMAIN OVER THE AREA THROUGH WEDNESDAY. HIGH PRESSURE WILL RETURN ON THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE TROUGH WILL APPROACH LATE SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... SEVERE THUNDERSTORM WATCH #559 ISSUED FOR THE ENTIRE TRI-STATE AREA UNTIL 7 PM. DEEP UPPER LOW WITH VIGOROUS SHORTWAVE ROTATING AROUND IT WILL MOVE THROUGH THE REGION THIS AFTERNOON. CAPE VALUES BASED OFF OF THE 12Z OKX UPPER AIR SOUNDING ARE AROUND 2000 J/KG...AND THIS IS SHOWING UP QUITE WELL ON MODEL GUIDANCE...WITH CAPE VALUES WELL OVER 2000 J/KG...AND CLOSE TO 2800 J/KG OVER CT. LIFTED INDEX IS -5.5C ON OKX SOUNDING...AND GENERALLY -3 TO -5C ON AVERAGE ON THE MODELS WITH THE LIFTED INDEX IN CT CLOSE TO -8C. TSTMS MOVING INTO ORANGE COUNTY...AND WILL BE OVERSPREADING THE REGION THROUGH THIS AFTERNOON. WITH COLD POOL ALOFT...DAMAGING WINDS AND LARGE HAIL IS EXPECTED. SPC DAY 1 OUTLOOK MENTIONS THE POSSIBILITY OF AN ISOLATED TORNADO...AND THIS CAN/T BE RULED OUT. COLD FRONT WILL BE SLOW TO ENTER THE AREA TONIGHT WHILE ADDITIONAL MID LEVEL IMPULSES PIVOT AROUND ONTARIO CLOSED UPPER LOW..SO CHANCE FOR SHOWERS/TSTMS CONTINUES INTO THE EVENING...THEN TAPERS OFF FROM WEST-EAST AFTER MIDNIGHT AS LOW LEVEL CAA SHUTS OFF SOURCE OF LIFT. TEMPS WILL BE SLIGHTLY BELOW NORMAL DUE TO CLOUD COVER AND ONSHORE MARITIME FLOW OUT EAST. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... COLD FRONT STALLS OVER OR JUST SOUTH OF THE AREA ON WED...WITH WEAK SFC TROUGHING REMAINING IN PLACE AND MID LEVEL IMPULSES MOVING ACROSS...WHICH SHOULD SPARK ISOLATED TO SCATTERED AFTERNOON SHOWERS AND POSSIBLE TSTMS. HAVE FORECAST CHANCE AFTERNOON/EARLY EVENING POP MAINLY ACROSS SOUTHERN CT...CLOSER TO UPPER COLD POCKET ASSOCIATED WITH THE UPPER LOW AS IT MOVES SE ACROSS NEW ENGLAND. INSTABILITY LOW FOR THE MOST PART...BUT ANY POCKETS OF STRONGER DAYTIME HEATING COULD SPARK A TSTM CAPABLE OF PRODUCING SOME HAIL. THU SHOULD BE A BETTER DAY...BUT WITH YET MORE MID LEVEL SHORTWAVE ENERGY RIDING ACROSS...WILL HAVE TO KEEP SLIGHT CHANCE POP IN THE FCST. TEMPS CONTINUE NEAR OR SLIGHTLY BELOW NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... PROGRESSIVE WEATHER PATTERN ON TAP FOR THE LONG TERM PERIOD. HIGH PRES MOVES OFFSHORE FRI NIGHT...THEN A SERIES OF UPPER DISTURBANCES AND SFC COLD FRONTS WILL MOVE THROUGH THE REGION STARTING ON SAT. BASED ON LATEST HPC/ECMWF/GFS GUIDANCE...WILL HOLD OFF ON PRECIP UNTIL SAT AFTERNOON...THEN PRECIP LINGERS THROUGH SUN. WEAK HIGH PRES OVERSPREADS THE REGION MON...THEN ANOTHER SYSTEM ON TAP FOR TUE. WILL CARRY CHANCE POPS IN THE EXTENDED. HIGHS WILL GENERALLY AVERAGE WITHIN A FEW DEGREES OF NORMAL EITHER WAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... TSTMS HAVE DEVELOPED ACROSS NRN TERMINALS. ADDITIONAL DEVELOPMENT IS POSSIBLE THIS AFTN BEHIND THE INITIAL WAVE OF ACTIVITY. ACROSS THE METRO...TSTMS NOW DEVELOPING ACROSS ERN PA. ADDITIONALLY...TSTM INITIATION OVER THE REGION IS POSSIBLE. EXTENDED TEMPO FOR TSRA. STORM MOTION WILL GENERALLY BE E/ENE AROUND 15KT. EXPECT WINDS TO SHIFT TO A NLY COMPONENT AT TIMES BEHIND TSTMS. AFTER CONVECTION DIES DOWN AFT 00Z...LINGERING LLVL MOISTURE MAY RESULT IN SCT-BKN LOW CLOUDS AND PERHAPS SOME VSBY RESTRICTIONS AS WINDS GO LGT. FOR NOW FEW020 USED EXCEPT KGON WHERE MVFR CIGS FCST. LOW CLOUDS MIX OUT WED MRNG WITH SCT-BKN CU IN THE AFTN. ISOLD-SCT TSTMS POSSIBLE...COVERAGE AND INTENSITY EXPECTED TO BE LESS THAN TODAY ATTM. OUTLOOK FOR 00Z THURSDAY THROUGH SATURDAY... HIGH PRES WED NIGHT THRU FRI. VFR WITH POCKETS OF MVFR OR LOWER IN EARLY MRNG FOG/STRATUS. COLD FRONT APPROACHES SAT WITH CHANCES FOR TSTMS. && .MARINE... SEVERE THUNDERSTORM WATCH #559 IN EFFECT UNTIL 7 PM. SUB-ADVISORY CONDITIONS EXPECTED ON THE WATERS THROUGH THE PERIOD. MODERATE AMBROSE JET THIS AFTERNOON MAY HAVE SOUTHERLY WINDS AROUND 15 KT ON WESTERN OCEAN WATERS/SOUND THIS AFTERNOON. TSTMS WILL OVERSPREAD THE WATERS AS A VIGOROUS SYSTEM TRACKS EAST. MARINERS WILL HAVE TO BE PREPARED FOR STRONG TO SEVERE STORMS. && .HYDROLOGY... CONVECTION TODAY EXPECTED TO PRODUCE AREAL QPF OF 0.25-0.50 INCH ACROSS MUCH OF SOUTHERN CT...AND 0.10-0.25 INCH ELSEWHERE. LOCAL QPF COULD BE DOUBLE THAT IN STRONGER TSTMS...CAUSING LOCALIZED PONDING. FLASH FLOOD THREAT MINIMAL GIVEN STORM MOTION AND CORFIDI VECTOR MAGNITUDES BOTH AROUND 20 KT. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && SYNOPSIS...BG NEAR TERM...MPS SHORT TERM...BG LONG TERM...MPS AVIATION...JMC MARINE...NV HYDROLOGY...BG
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE NEW YORK NY 1108 AM EDT TUE JUL 7 2009 CTZ005>012-NJZ002>006-011-NYZ067>081-081000- 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- 1108 AM EDT TUE JUL 7 2009 ...SEVERE THUNDERSTORM WATCH 559 IN EFFECT UNTIL 7 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN CONNECTICUT...NORTHEAST NEW JERSEY AND SOUTHEAST NEW YORK. .DAY ONE...THIS AFTERNOON AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY HAZARDOUS WEATHER NOT EXPECTED AT THIS TIME. .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. ANZ330-335-338-340-345-350-353-355-081000- 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- 1108 AM EDT TUE JUL 7 2009 ...SEVERE THUNDERSTORM WATCH 559 IN EFFECT UNTIL 7 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS. .DAY ONE...THIS AFTERNOON AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY HAZARDOUS WEATHER NOT EXPECTED AT THIS TIME. .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. MPS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 1229 PM EDT TUE JUL 7 2009 CTZ005-009-NYZ068>071-071730- NORTHERN FAIRFIELD-NORTHERN WESTCHESTER-PUTNAM-ROCKLAND-SOUTHERN FAIRFIELD-SOUTHERN WESTCHESTER- 1229 PM EDT TUE JUL 7 2009 ...STRONG THUNDERSTORMS WILL IMPACT FAIRFIELD...PUTNAM...ROCKLAND AND WESTCHESTER COUNTIES... AT 1226 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM HOPEWELL JUNCTION TO YORKTOWN HEIGHTS TO NORWOOD...OR ALONG A LINE EXTENDING FROM 9 MILES SOUTHEAST OF POUGHKEEPSIE TO 8 MILES NORTHWEST OF LAKE CARMEL TO 6 MILES EAST OF PEEKSKILL TO TAPPAN...AND MOVING EAST AT 30 MPH. THESE STORMS WILL BE... NEAR MAHOPAC BY 1235 PM. NEAR MOUNT KISCO BY 1240 PM. NEAR WHITE PLAINS BY 1245 PM. NEAR HARRISON BY 1250 PM. NEAR SHERMAN BY 1255 PM. NEAR RIDGEFIELD BY 100 PM. SMALL HAIL...AND WINDS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS. 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.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 117 PM EDT TUE JUL 7 2009 CTZ005-006-009-010-071815- NORTHERN FAIRFIELD-NORTHERN NEW HAVEN-SOUTHERN FAIRFIELD-SOUTHERN NEW HAVEN- 117 PM EDT TUE JUL 7 2009 ...STRONG THUNDERSTORMS WILL IMPACT FAIRFIELD AND NEW HAVEN COUNTIES... AT 117 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM WOODBURY CENTER TO DARIEN...OR ALONG A LINE EXTENDING FROM 6 MILES NORTH OF SOUTHBURY TO NORWALK...AND MOVING EAST AT 25 MPH. THESE STORMS WILL BE... NEAR FAIRFIELD BY 125 PM. NEAR TRUMBULL BY 130 PM. NEAR BRIDGEPORT BY 135 PM. NEAR WATERBURY BY 140 PM. NEAR STRATFORD BY 145 PM. NEAR WOLCOTT BY 150 PM. SMALL HAIL...AND WINDS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS. 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.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 126 PM EDT TUE JUL 7 2009 NYZ078-071830- NORTHWEST SUFFOLK- 126 PM EDT TUE JUL 7 2009 ...A STRONG THUNDERSTORM WILL IMPACT THE NORTH SHORE OF SUFFOLK COUNTY EAST OF PORT JEFFERSON... AT 122 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 5 MILES NORTHWEST OF NORTHPORT MOVING EAST SOUTHEAST AT 25 MPH. WINDS OF 40 TO 50 MPH ARE EXPECTED WITH THIS STORM. 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. JST
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW YORK NY 132 PM EDT TUE JUL 7 2009 NYZ078-071732- NORTHWEST SUFFOLK- 132 PM EDT TUE JUL 7 2009 ...A SEVERE THUNDERSTORM WARNING IS NOW IN EFFECT OF THE THE NORTH SHORE OF SUFFOLK COUNTY... JST
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW YORK NY
141 PM EDT TUE JUL 07 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0124 PM HAIL NAUGATUCK 41.49N 73.05W
07/07/2009 E0.88 INCH NEW HAVEN CT NWS EMPLOYEE
NICKEL SIZE HAIL
&&
JPPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW YORK NY
146 PM EDT TUE JUL 07 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0143 PM HAIL 3 E WATERBURY 41.56N 72.97W
07/07/2009 E0.75 INCH NEW HAVEN CT TRAINED SPOTTER
PENNY SIZE HAIL
&&
JPThe Brookhaven radar (KOKX), 25 km away, was scanning. The volume nearest the first event began at 17:50 UTC.
17 thunderstorm wind, 8 hail, 2 flash flood. Local standard time, as filed.
A tree was downed my thunderstorm winds.
Wires were downed near Hay Beach.
Numerous trees were downed.
Wires were downed by thunderstorm winds.
Long Beach Rd. was closed due to flooding.
Deer Park Ave. was closed at Sunrise Hwy. due to flooding.
Golf ball size hail was reported by a trained spotter.
A severe thunderstorm that produced storm damage in Bergen county in|northeastern New Jersey moved into Yonkers around 11:25 pm as the|storm intensified. Doppler weather radar analysis would classify|the storm as a supercell with a strong mesocyclone at this time. A|large area of very strong downburst winds downed numerous large|trees that fell on structures, power lines and cars. The worst damage|observed in the area was in Trevor Park around the Hudson River|Museum where winds were estimated to have gusted up to 100 mph. Some minor damage appeared to occur to the roof of the Museum with a few shingles blown off. Nearly all trees appeared to have fallen to the east or southeast. The damage area extended east to North Broadway and into Grant Park on Park Ave where numerous large trees were also knocked over falling to the east or southeast. Downed large trees were also observed in Oakland Cemetery.
Downed trees were also observed in Mount Vernon along West Street|and Macquesten Parkway North where winds of 70 mph were estimated to|have occurred. Again, all trees appeared to fall to the southeast.|There was additional tree damage to a lesser degree to the north|observed along and near the Cross County Parkway.
In Bronxville, several trees were seen downed along the Bronx River|Parkway from exits 1 to 3. In Eastchester and Tuckahoe, several large|trees were downed in the vicinity of Ridge and Governors Roads. A|large tree here fell on power lines snapping a telephone pole in|half. Winds in this area were estimated at 80 mph.
In addition to the wind damage, there was extensive hail from the|storm along with torrential rain. The hail accumulated to several|inches in Yonkers and was still visible this morning. Rain swept the|hail into some locations to depth over a foot. In one location on|Hoover Road in northern Yonkers...up to 4 feet of hail accumulated|inside a home after the drainage became clogged.
Penny size hail was reported.
A tree was downed into a bedroom, injuring one woman.
Numerous trees and branches were downed by thunderstorm winds.
Quarter size hail was reported.
Large trees were downed.
Large trees were downed.
Quarter size hail was reported by a trained spotter.
Numerous trees were downed.
Nickel size hail was reported by emergency management officials.
Nickel size hail was reported by emergency management officials.
Nickel size hail was reported by emergency management officials.
Numerous trees were downed by thunderstorm winds.
Penny size hail was reported by a trained spotter.
Numerous trees were downed by high winds.
Numerous trees were downed by thunderstorm winds.
The Saw Mill River Parkway was closed due to downed trees.
Numerous trees were downed.
Numerous trees were downed by thunderstorm winds.
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: 188694, 188695, 188682, 188685, 189500, 189502, 188672, 188690, 188673, 188687, 188696, 188677, 188689, 188686, 188674, 188688, 188683, 188675, 188676, 188678, 188697, 188679, 188680, 188681, 188699, 188684, 188698.