Slow moving thunderstorms developed in a tropical airmass, which resulted in very heavy rain and flash flooding across portions of Essex County New Jersey.
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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 OKX wrote it up.
Slow moving thunderstorms developed in a tropical airmass, which resulted in very heavy rain and flash flooding across portions of Essex County New Jersey.
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 Aug 12, 7:36 PM EST, 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 836 PM EDT WED AUG 12 2009 .SYNOPSIS... WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG A STATIONARY BOUNDARY SOUTH OF THE REGION THROUGH THE END OF THE WEEK. HIGH PRESSURE BUILDS OVER THE AREA FOR THE WEEKEND...THEN A SERIES OF WEAK COLD FRONTS WILL IMPACT THE REGION NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... SCATTERED TO NUMEROUS SHOWERS AND ISOLATED TSTMS CONTINUE TO FIRE OVER PORTIONS OF THE AREA...AIDED BY RIGHT ENTRANCE REGION OF UPPER JET STREAK TO THE NORTH AND TRANSIENT MID LEVEL SHORTWAVES...AS WELL AS UPSLOPE FLOW IN PUTNAM/ORANGE COUNTIES AND LOW LEVEL CONVERGENCE ALONG SUBTLE BOUNDARIES. CELLS CONTINUE TO BE SLOW MOVERS AND CAPABLE OF LEAVING 1-2 INCHES OF RAIN PER HOUR...WITH ISOLATED FLASH FLOODING STILL POSSIBLE. INSTABILITY LESSENS SOMEWHAT AFTER MIDNIGHT PER FCST SOUNDINGS...SO WITH ALL ELSE BEING EQUAL...THREAT FOR HEAVY RAIN SHOULD DIMINISH OVERNIGHT...WITH STRATUS LOWERING AND THICKENING VIA E-NE MARITIME FLOW AND COOLING BENEATH LOW LEVEL INVERSION. ANOTHER MUGGY NIGHT WITH PATCHY FOG OVER THE INTERIOR AND ESPECIALLY WHERE HEAVIER RAINS HAVE FALLEN. LOWS IN THE MID AND UPPER 60S...AND NEAR 70 IN/AROUND NYC. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... WITH LOW PRES SOUTH OF LONG ISLAND AND A DEEP MID-LEVEL TROUGH WITH SEVERAL STRONG SHORTWAVES ROTATING THROUGH ITS BASE ON THU...WILL KEEP CHANCE POPS IN THE FCST FOR SHOWERS/TSTMS. IT IS STILL UNCERTAIN JUST HOW FAR NORTH THE LOW WILL DRIFT...BUT WITH DEWPOINTS IN THE UPPER 60S AND TEMPS APPROACHING 80...WILL LOOK FOR MORE CONVECTION TO FIRE UP. GFS ALSO INDICATING AN AREA OF HEAVY RAIN OVER NJ/NYC/LONG ISLAND THAT THE NAM IS NOT PICKING UP ON...PROBABLY DUE TO CONVECTIVE FEEDBACK ISSUES IN THE GFS. LIKE TODAY...EMBEDDED TSTMS WITH LOCALLY HEAVY RAIN POSSIBLE. CONDITIONS DRY OUT THU NIGHT. FRI WILL FEATURE SFC HIGH PRES BUILDING INTO THE EASTERN SEABOARD...BUT UPPER TROUGH WILL BE SLOW TO DEPART. WILL KEEP SLIGHT CHANCE TO CHANCE POPS FOR FRI AFTERNOON. WITH WARMER TEMPS AND HIGH DEWPOINTS...INSTABILITY LEVELS WILL BE HIGHER THAN THU...SO ISOLATED STRONG STORMS ARE POSSIBLE. HIGH PRES OVER THE AREA SAT WILL KEEP THE AREA MAINLY DRY AND MILD WITH HIGHS IN THE 80S TO NEAR 90. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... SEVERAL MID-LEVEL SHORTWAVES WILL MOVE THROUGH THE REGION STARTING LATE SUN THROUGH LATE MON. WILL KEEP THE AREA MAINLY DRY WITH A HIDDEN SLIGHT CHANCE POP AS SOME AFTERNOON CONVECTION IS POSSIBLE. BY THE MIDDLE OF THE WEEK...A STRONGER COLD FRONT APPROACHES...AND WILL BUMP UP POPS TO CHANCE FOR TUE/WED. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... MAINLY MVFR CIGS THIS EVENING SHOULD LOWER TONIGHT VIA CONTINUED E AND THEN NE MARITIME FLOW AND BOUNDARY LAYER COOLING...WITH EVENTUAL IFR CIGS LATE THIS EVENING AT KISP/KJFK AND AFTER MIDNIGHT ELSEWHERE...GENERALLY A COUPLE OF HOURS LATER THAN 22Z GFS LAMP FORECAST. CIGS SHOULD GRADUALLY IMPROVE AFTER DAYBREAK...WITH ANOTHER CHANCE OF SHOWERS/TSTMS AS LOW PRESSURE PASSES SOUTH AND EAST OF LONG ISLAND. STILL TOO EARLY TO PINPOINT EXACTLY WHERE TSTMS WILL DEVELOP THU AFTERNOON...AND HAVE OMITTED FROM TAF FOR NOW. OUTLOOK...POSSIBLE SUB-VFR WITH SCATTERED SHOWERS/TSTMS THU EVENING...AND THEN PATCHY FOG LATE THU NIGHT INTO FRI MORNING. && .MARINE... GENERALLY SUB SMALL CRAFT ADVISORY CONDITIONS EXPECTED. STATIONARY FRONT REMAINS JUST SOUTH OF THE WATERS...AND LOW PRES WILL SLOWLY TRACK ALONG THIS BOUNDARY TONIGHT THROUGH THU...FOLLOWED BY A COLD FRONT AND UPPER TROUGH ON FRI. OCEAN SEAS MAY BUILD CLOSE TO 5 FT LATE THU AS THE LOW PASSES THROUGH THE WATERS. HIGH PRES BUILDS INTO THE WATERS THIS WEEKEND. && .HYDROLOGY... SHOWERS AND TSTMS THIS EVENING...GENERALLY TAPERING OFF AFTER MIDNIGHT. BASIN AVERAGE QPF OF 1/4 TO 1/2 INCH WITH LOCALIZED AMOUNTS OF OVER AN INCH POSSIBLE IN ANY SLOW MOVING STORMS. LOCALIZED FLASH FLOODING STILL POSSIBLE. SCT AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AND FRIDAY AFTERNOON...MAINLY ACROSS CITY AND INTERIOR. LOCALIZED URBAN AND POOR DRAINAGE FLOODING ISSUES POSSIBLE ONCE AGAIN WITH SLOW MOVING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && EVENING UPDATE/AVIATION...GOODMAN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW YORK NY 411 AM EDT WED AUG 12 2009 CTZ005-006-009-NJZ002>006-011-NYZ067>077-130815- NORTHERN FAIRFIELD-NORTHERN NEW HAVEN-SOUTHERN FAIRFIELD- 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- 411 AM EDT WED AUG 12 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN CONNECTICUT...NORTHEAST NEW JERSEY AND SOUTHEAST NEW YORK. .DAY ONE...TODAY AND TONIGHT. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE AREA THIS AFTERNOON INTO THIS EVENING. THIS ACTIVITY WILL BE SLOW MOVING WITH THE POTENTIAL FOR HEAVY DOWNPOURS. AS A RESULT THERE IS A LOW END THREAT FOR URBAN AND POOR DRAINAGE FLASH FLOODING DURING THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME THAT WOULD MEET NATIONAL WEATHER SERVICE WARNING CRITERIA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. && 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. CTZ007-008-010>012-NYZ078>081-130815- NORTHERN MIDDLESEX-NORTHERN NEW LONDON-SOUTHERN NEW HAVEN- SOUTHERN MIDDLESEX-SOUTHERN NEW LONDON-NORTHWESTERN SUFFOLK- NORTHEASTERN SUFFOLK-SOUTHWESTERN SUFFOLK-SOUTHEASTERN SUFFOLK- 411 AM EDT WED AUG 12 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN CONNECTICUT AND SOUTHEAST NEW YORK. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME THAT WOULD MEET NATIONAL WEATHER SERVICE WARNING CRITERIA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. && 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. ANZ330-335-338-340-345-350-353-355-130815- 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- 411 AM EDT WED AUG 12 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME THAT WOULD MEET NATIONAL WEATHER SERVICE WARNING CRITERIA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. && 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.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW YORK NY
644 PM EDT WED AUG 12 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0510 PM FLASH FLOOD SOUTHBURY 41.49N 73.22W
08/12/2009 NEW HAVEN CT LAW ENFORCEMENT
RT 172 IN SOUTHBURY CLOSED DUE TO FLOODING
0547 PM FLASH FLOOD 5 N DANBURY 41.47N 73.47W
08/12/2009 FAIRFIELD CT LAW ENFORCEMENT
SAW MILL RD CLOSED DUE TO FLOODING NEAR RT 39.
&&
SMITHThe Philadelphia radar (KDIX), 93 km away, was scanning. The volume nearest the first event began at 00:59 UTC.
1 flash flood, 1 heavy rain. Local standard time, as filed.
In Livingston, cars were stranded in high water on East Cedar Street, Falcon Rd. and South Orange Ave. near the Florham Park town line. The Peckman River at Verona also exceeded it's flood stage of 3.5 ft. and crested at 4.01 ft. around 11 pm.
A combination of heavy rainfall and winds of 30-40 mph caused a tree to fall into the house located at 31 Eagle Rock Avenue in Roseland.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New Jersey in 2009Every state in 2009This day in weather historyWarnings in New Jersey, 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: 192716, 195136.