A cold pool of air aloft triggered isolated thunderstorms across southeast New York, with one lightning strike reported in Upper Manhattan.
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 cold pool of air aloft triggered isolated thunderstorms across southeast New York, with one lightning strike reported in Upper Manhattan.
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 Apr 17, 7:01 PM EST, 1 hour 4 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
801 PM EDT SUN APR 17 2011
.SYNOPSIS...
LOW PRESSURE TRACKS SLOWLY NORTHEAST THROUGH SOUTHEASTERN CANADA
THROUGH MONDAY NIGHT...WITH AN ASSOCIATED TROUGH OF LOW PRESSURE
CROSSING THE TRI-STATE TONIGHT...AS HIGH PRESSURE BUILDS INTO OUR
SOUTH. A COLD FRONT CROSSES THE AREA MONDAY NIGHT...THEN STALLS
OUT TO OUR SOUTH INTO WEDNESDAY...AS CANADIAN HIGH PRESSURE
BUILDS IN ACROSS SOUTHEASTERN CANADA AND THE NORTHEASTERN UNITED
STATES. TWO STORM SYSTEMS IMPACT THE REGION LATE THIS WEEK...THE
FIRST FROM WEDNESDAY NIGHT INTO THURSDAY AND THE SECOND FROM
FRIDAY NIGHT INTO NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
APPROACHING SHORTWAVE TROUGH WILL BRING SOME SCATTERED SHOWERS
ACROSS THE FORECAST AREA THIS EVENING. THUNDERSTORMS REMOVED
FROM FORECAST BASED ON ONGOING ACTIVITY AND LOSS OF DAYTIME
INSTABILITY. BEST CHANCE LOOKS TO BE NORTH OF THE AREA WHERE
STEEPER MID LEVEL LAPSE RATES EXIST.
SHOULD SEE DECENT CLEARING IN THE WAKE OF THE SHORTWAVE LATE
TONIGHT...SO TEMPERATURES WILL FALL OFF OVERNIGHT...BUT THE
BOUNDARY LAYER SHOULD REMAIN SUFFICIENTLY WELL MIXED TO ALLOW FOR
ANYTHING BEYOND MODEST RADIATIONAL COOLING. MAV/MET GUIDANCE WERE
FAIRLY CLOSE...AND CONSISTENT WITH THIS REASONING...SO USED A
BLEND FOR LOWS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE FIRST PART OF MONDAY SHOULD BE DRY...THEN A PASSING COLD FRONT
MONDAY AFTERNOON/MONDAY NIGHT COUPLED WITH A WEAK SHORTWAVE MOVING
THROUGH IN THE LOW TO MID LEVELS SHOULD PROMOTE INCREASING CHANCE
OF SHOWERS FROM NW TO SE FROM MONDAY AFTERNOON INTO MONDAY EVENING
(RESTRICTED LIKELY POPS TO NORTHERN TIER CLOSEST TO BEST IMPACT
FROM PASSING SHORTWAVE)...WITH POPS TAPERING TO SLIGHT CHANCE LATE
MONDAY NIGHT. USED A BLEND OF 2/3 MET/MAV BLEND AND 1/3 MIXING
DOWN FROM 900 HPA - PER BUFKIT SOUNDINGS - FOR HIGHS MONDAY...AND
A BLEND OF 2/3 MAV/MET BLEND AND 1/3 NAM 2-METER TEMPERATURES FOR
LOWS MONDAY NIGHT - NAM 2-METER TEMPERATURES FAIR PRETTY WELL IN
THESE SHALLOW LOW LEVEL POST-FRONTAL COLD ADVECTION CASES.
TUESDAY INTO WEDNESDAY WILL FEATURE A FRONTAL BOUNDARY STALLED TO
THE S...WITH SW FLOW ALOFT...WITH SHORTWAVES PASSING ALOFT...AND
DEVELOPING LOW LEVEL WARM ADVECTION AS SOUTHERLY FLOW SETS UP IN
THE UPPER PART OF THE BOUNDARY LAYER...WITH AN EASTERLY FLOW AT
THE SURFACE - CLASSIC OVER RUNNING PATTERN. HAVE TIMED THE BEST
POPS TUESDAY INTO WEDNESDAY WITH THE PROJECTED PASSAGE OF A
SHORTWAVE TROUGH LATE TUESDAY AFTERNOON AND TUESDAY EVENING
(LIKELY POPS N TIER WITH BETTER FORCING).
WEDNESDAY WILL SEE STEADIER RAIN GIVE WAY TO LIGHT RAIN/DRIZZLE
FROM S TO N AS 850 WARM FRONT LIFTS TO THE N WHILE SFC WRM FRONT
STAYS TO THE S.
FOR TEMPERATURES TUESDAY-WEDNESDAY BLENDED AVAILABLE GUIDANCE WITH
NAM 2-METER TEMPERATURES TO REFLECT IMPACT OF COLD AIR DAMMING
(WITH SFC HIGH BUILDING OVER SE CANADA)...AND PRECIPITATION INTO
THE DAMMING HIGH - NAM 2-METER TEMPERATURES GENERALLY PERFORM
FAIRLY WELL IN THIS SCENARIO. EXPECT BELOW NORMAL HIGHS AND LOWS
SLIGHTLY ABOVE NORMAL AS A RESULT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ANOTHER PAC STORM SYSTEM IS FORECAST TO TRACK ACROSS THE GREAT LAKES
AT THE ONSET OF THE PERIOD SENDING A MODERATE COLD FRONT ACROSS THE
AREA. GLOBAL MODELS STILL IN SOME DISAGREEMENT WITH THE MAGNITUDE
OF THE PARENT LOW AND TIMING OF THE COLD FRONT. THAT BEING THE
CASE...WE ARE STILL LOOKING AT A COLD FRONTAL PASSAGE WED NIGHT.
ONLY LOOKING AT SHOWERS WITH MARGINAL INSTABILITY AND THE BEST UPPER
SUPPORT PASSING TO THE NW OF THE FORECAST AREA.
RIDGING BOTH ALOFT AND THE SURFACE TRANSLATES EAST FOR THE END OF
THE WEEK WITH A BRIEF SHOT OF DRY...SEASONABLE WEATHER. YET ANOTHER
PAC STORM SYSTEM IS FORECAST TO TRACK NE ACROSS THE GREAT LAKES NEXT
WEEKEND...FIRST IMPACTING THE AREA WITH OVERRUNNING RAINS FRI NIGHT
INTO SAT AND THEN POSSIBLE CONVECTION ALONG AND AHEAD OF THE
TRAILING COLD FRONT SAT NIGHT.
THE GFS CONTINUES TO BE STRONGER...MORE AMPLIFIED WITH THESE LOWS
VERSUS THE ECMWF...WHICH IS FLATTER AND SOMEWHAT MORE PROGRESSIVE.
NEXT WEEKEND THE DIFFERENCES BECOME QUITE APPARENT AS THE GFS SENDS
A MODERATE COLD FRONT ACROSS THE AREA SAT NIGHT...WHILE THE ECMWF
STALLS A WEAK FRONT ACROSS THE AREA WITH LIGHT OVERRUNNING
PRECIPITATION CONTINUING INTO SUN. THE GFS AT THIS TIME IS AN
OUTLIER WITH THE GLOBAL MODEL ENSEMBLE. THIS WOULD SEEM REASONABLE
WITH THE NEARLY ZONAL FLOW.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR. AN ISOLATED THUNDERSTORM POSSIBLE...ESPECIALLY NORTH AND WEST
OF THE NYC TERMINALS...THROUGH 02Z. AN REMAINING WIND GUSTS WILL
BE SUBSIDING BY 03Z...THEN WINDS BECOME MORE WESTERLY. DURING
MONDAY WESTERLY WINDS GRADUALLY SHIFT TO SOUTHWEST AND ALONG THE
COAST SEA BREEZE INFLUENCES WILL BE LIKELY AFTER 16Z. GUSTS WILL
BECOME POSSIBLE AT KJFK. SOME UNCERTAINTY WITH DEVELOPMENT OF THE
SEA BREEZE INFLUENCES.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
MONDAY NIGHT...VFR WITH SCATTERED SHOWERS.
TUESDAY THROUGH WEDNESDAY NIGHT...PERIODS OF SUB-VFR LIKELY IN
SHOWERS. GUSTY WINDS/LLWS POSSIBLE. THUNDER ALSO POSSIBLE AHEAD
OF A COLD FRONT.
THURSDAY...VFR WITH GUSTY NORTHWESTERLY WINDS.
FRIDAY...VFR.
&&
.MARINE...
HAVE ENOUGH LOW LEVEL INSTABILITY EARLY THIS EVENING...THEN A 60
KT LOW LEVEL JET PASSING BY THROUGH MIDNIGHT (WITH LOW LEVEL
INVERSION LIMITING MIXING TO AT BEST 50 PERCENT)...TO WARRANT
CONTINUING SCA ON ALL WATERS THROUGH MIDNIGHT...THEN CONTINUE SCA
ON COASTAL OCEAN ZONES THROUGH MONDAY WITH SEAS EXPECTED TO
GRADUALLY FALL FROM CURRENT LEVELS OF 6 TO 12 FT.
WITH EASTERLY FLOW DEVELOPING BY LATE TUESDAY...THERE IS SOME
POTENTIAL FOR SEAS TO STAY UP ON THE COASTAL OCEAN WATERS THROUGH
WEDNESDAY.
AS FOR WINDS FROM MONDAY-WEDNESDAY...FOR NOW FORECAST TO STAY
BELOW SCA LEVELS...BUT THIS IS NOT A CERTAINTY...AS ANY WAVE OF
LOW PRESSURE WHICH COULD RIDE ALONG A STALLED OUT BOUNDARY TO OUR
SOUTH COULD INCREASE THE PRESSURE GRADIENT JUST ENOUGH TO BRING
WINDS FROM JUST BELOW SCA LEVELS TO SCA LEVELS IN THIS TIME FRAME.
&&
.HYDROLOGY...
RIVERS OVER ROCKLAND/WESTCHESTER/PASSAIC/BERGEN COUNTY ARE
FORECAST TO REMAIN IN FLOOD INTO TONIGHT...REFER TO THE LATEST
AREAL AND RIVER FLOOD WARNINGS FOR DETAILS.
A FLOOD WARNING HOWEVER REMAINS IN EFFECT FOR SPOTS ALONG THE
CONNECTICUT...STILL AND PASSAIC RIVERS IN ADJACENT HYDROLOGIC
SERVICE AREAS...BUT WITHIN THE OFFICE/S COUNTY WARNING AREA.
PLEASE SEE WWW.WEATHER.GOV/NYC FOR MORE INFORMATION.
LESS THAN A TENTH OF AN INCH OF QPF IS EXPECTED FROM ANY SHRA/TSRA
THIS EVENING. THERE IS THE POTENTIAL FOR UP TO A HALF AN INCH OF
RAINFALL FROM LATE MONDAY NIGHT INTO WEDNESDAY...WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. GIVEN THE LONG DURATION THIS
PRECIPITATION IS EXPECTED TO BE SPREAD OVER...LIMITED HYDROLOGIC
IMPACT IS EXPECTED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ330-335-
338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ350-353-355.
&&
SYNOPSIS...MALOIT
NEAR TERM...MALOIT/DW
SHORT TERM...MALOIT
LONG TERM...DW
AVIATION...MET
MARINE...MALOIT/DW
HYDROLOGY...MALOITHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE NEW YORK NY 734 PM EDT SUN APR 17 2011 NJZ103-104-182345- WESTERN BERGEN-EASTERN BERGEN- 734 PM EDT SUN APR 17 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST NEW JERSEY. .DAY ONE...TONIGHT. A RIVER FLOOD WARNING REMAINS IN EFFECT FOR THE RAMAPO RIVER AT MAHWAH. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. 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. CTZ005>012-NJZ002-004-006-105>108-NYZ067>075-078>081-176>179-182345- NORTHERN FAIRFIELD-NORTHERN NEW HAVEN-NORTHERN MIDDLESEX- NORTHERN NEW LONDON-SOUTHERN FAIRFIELD-SOUTHERN NEW HAVEN- SOUTHERN MIDDLESEX-SOUTHERN NEW LONDON-WESTERN PASSAIC- EASTERN PASSAIC-HUDSON-WESTERN ESSEX-EASTERN ESSEX-WESTERN UNION- EASTERN UNION-ORANGE-PUTNAM-ROCKLAND-NORTHERN WESTCHESTER- SOUTHERN WESTCHESTER-NEW YORK (MANHATTAN)-BRONX- RICHMOND (STATEN ISLAND)-KINGS (BROOKLYN)-NORTHWESTERN SUFFOLK- NORTHEASTERN SUFFOLK-SOUTHWESTERN SUFFOLK-SOUTHEASTERN SUFFOLK- NORTHERN QUEENS-NORTHERN NASSAU-SOUTHERN QUEENS-SOUTHERN NASSAU- 734 PM EDT SUN APR 17 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN CONNECTICUT...NORTHEAST NEW JERSEY AND SOUTHEAST NEW YORK. .DAY ONE...TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. 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. ANZ330-335-338-340-345-350-353-355-182345- 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- 734 PM EDT SUN APR 17 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS. .DAY ONE...TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. 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
633 PM EDT SUN APR 17 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM FLOOD RAMSEY 41.06N 74.15W
04/17/2011 BERGEN NJ TRAINED SPOTTER
SOME BASEMENT FLOODING REPORTED.
&&
JMPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NEW YORK NY
827 PM EDT SUN APR 17 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0930 PM NON-TSTM WND DMG NORTH MASSAPEQUA 40.70N 73.46W
04/16/2011 NASSAU NY PUBLIC
DOOR BLOWN OFF ITS HINGES. DOOR AND GLASS BROKEN.
0947 PM FLOOD WOODLAND PARK 40.89N 74.19W
04/16/2011 PASSAIC NJ EMERGENCY MNGR
RT 46 AT ANDREW DRIVE AND MC BRIDE AVE FLOODED. FIRE
DEPARTMENT USING BOATS FOR AUTO EVACUATIONS
1015 PM NON-TSTM WND DMG SADDLE BROOK 40.90N 74.10W
04/16/2011 BERGEN NJ TRAINED SPOTTER
TREE DOWN WITH PROPERTY DAMAGE ON STEINWAY ROAD
1040 PM FLOOD RIDGEWOOD 40.98N 74.11W
04/16/2011 BERGEN NJ TRAINED SPOTTER
IRVING STREET AT FRANKLIN AVENUE CLOSED BY POLICE AND
FIRE DEPARTMENT DUE TO FLOODING OF HOHOKUS BROOK
1049 PM FLOOD RIDGEWOOD 40.98N 74.11W
04/16/2011 BERGEN NJ TRAINED SPOTTER
LINWOOD AVENUE BETWEEN NORTH MAPLE AND FAIRFIELD CLOSED
BY PD DUE TO FLOODING OF HOHOKUS BROOK
1054 PM FLOOD PARAMUS 40.95N 74.07W
04/16/2011 BERGEN NJ TRAINED SPOTTER
MULTIPLE LANES OF NJ ROUTE 17 NEAR LINWOOD AVENUE CLOSED
BY PD DUE TO FLOODING
1120 PM FLOOD SADDLE RIVER 41.03N 74.10W
04/16/2011 BERGEN NJ TRAINED SPOTTER
SADDLE RIVER OVERFLOWING ITS BANKS. ROCHELLE AVENUE
FLOODED AT ESSEX STREET AND BECKER STREET.
1250 AM FLOOD FAIR LAWN 40.94N 74.12W
04/17/2011 BERGEN NJ TRAINED SPOTTER
WAGERAW ROAD SOUTH OF LINCOLN AVENUE CLOSED BY PD DUE TO
FLOODING OF THE PASSAIC RIVER
0100 AM NON-TSTM WND DMG RIDGEWOOD 40.98N 74.11W
04/17/2011 BERGEN NJ TRAINED SPOTTER
TREE DOWN TAKING MULTIPLE POWER LINES DOWN WITH IT. FIRE
AND POLICE DEPARMENTS CLOSING SEVERAL STREETS NEAR
HEMPSTEAD ROAD DUE TO SEVERAL LINES DOWN ON THE ROADWAY
0645 AM FLOOD CLIFTON 40.86N 74.16W
04/17/2011 PASSAIC NJ BROADCAST MEDIA
FLOODING ON US 46 EASTBOUND AT CR 628. ALL LANES CLOSED.
0700 AM FLOOD RAMSEY 41.06N 74.15W
04/17/2011 BERGEN NJ TRAINED SPOTTER
BASEMENT FLOODING REPORTED ON WYCKOFF AVENUE...NOTTINGHAM
ROAD...AND BUCKINGHAM ROAD.
0943 AM FLOOD WAYNE 40.95N 74.25W
04/17/2011 PASSAIC NJ BROADCAST MEDIA
FLOODING ON NJ 23 FROM CR 631 TO NORTH OF US 202. ALL
LANES CLOSED IN BOTH DIRECTIONS.
&&
JMThe Brookhaven radar (KOKX), 90 km away, was scanning. The volume nearest the first event began at 01:02 UTC.
1 lightning. Local standard time, as filed.
Lightning struck the top of the building located at 621 West 188th Street, near Wadsworth Avenue in Upper Manhattan.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2011Every state in 2011This day in weather historyWarnings in New York, April 2011
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: 301892.