Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 66, NWS New York, NY

August 12, 2021Orange County, Rockland County, New York; Bergen County, Passaic County, New Jersey

NWS New York, NY issued this severe thunderstorm warning at Aug 12, 2021, 4:07 PM EDT for Orange County, Rockland County, New York; Bergen County, Passaic County, New Jersey. It was in force for 41 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 12, 2021, 4:07 PM EDT (20:07 UTC)
Expired
Aug 12, 2021, 4:48 PM EDT
In force
41 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Bergen County, NJ, Passaic County, NJ, Orange County, NY, Rockland County, NY

The radar

The Brookhaven radar (KOKX), 121 km from the middle of the area, began a volume at 20:07 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 12, 4:45 PM EDTTSTM WND DMG1 Sw Wyckoff, NJPOLICE REPORT FALLEN TREE AND DOWNED WIRES ON TERRACE HEIGHTS DR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.1 hours before the alert went out and 121 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 278 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -82 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
278 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1400 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-82 m²/s²
0-3 km storm-relative helicity
-47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

063 
WUUS51 KOKX 122007
SVROKX
NJC003-031-NYC071-087-122100-
/O.NEW.KOKX.SV.W.0066.210812T2007Z-210812T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New York NY
407 PM EDT Thu Aug 12 2021

The National Weather Service in Upton NY has issued a

* Severe Thunderstorm Warning for...
  Passaic County in northeastern New Jersey...
  Northwestern Bergen County in northeastern New Jersey...
  Orange County in southeastern New York...
  Rockland County in southeastern New York...

* Until 500 PM EDT.

* At 406 PM EDT, severe thunderstorms were located along a line
  extending from Montague to near Branchville to Blairstown, moving
  east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  New City, West Milford, Monsey, Nanuet, Ramsey, Ringwood,
  Haverstraw, Pompton Lakes, Suffern, Port Jervis, Monroe, West
  Point, Warwick, Goshen and Sloatsburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4150 7400 4146 7400 4140 7395 4132 7398
      4129 7394 4125 7397 4115 7389 4112 7389
      4096 7418 4096 7428 4100 7430 4103 7442
      4102 7443 4105 7445 4104 7450 4107 7449
      4109 7450 4120 7437 4136 7469 4139 7472
TIME...MOT...LOC 2006Z 263DEG 35KT 4130 7482 4111 7472 4099 7499 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
2 follow-up statements
541 
WWUS51 KOKX 122028
SVSOKX

Severe Weather Statement
National Weather Service New York NY
428 PM EDT Thu Aug 12 2021

NJC003-031-NYC071-087-122100-
/O.CON.KOKX.SV.W.0066.000000T0000Z-210812T2100Z/
Passaic NJ-Bergen NJ-Orange NY-Rockland NY-
428 PM EDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR PASSAIC...NORTHWESTERN BERGEN...SOUTHERN ORANGE AND ROCKLAND
COUNTIES...

At 427 PM EDT, severe thunderstorms were located along a line
extending from Unionville to near Kinnelon to Hackettstown, moving
east at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
New City, West Milford, Monsey, Nanuet, Ramsey, Ringwood, Haverstraw,
Pompton Lakes, Suffern, Warwick, Sloatsburg, Pearl River,
Bloomingdale, Greenwood Lake and Pomona.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4105 7446 4110 7449 4120 7437 4132 7460
      4133 7461 4123 7395 4115 7389 4112 7389
      4096 7418 4096 7428 4100 7430 4103 7442
      4102 7443
TIME...MOT...LOC 2027Z 288DEG 46KT 4128 7455 4103 7439 4087 7481 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
811 
WWUS51 KOKX 122048
SVSOKX

Severe Weather Statement
National Weather Service New York NY
448 PM EDT Thu Aug 12 2021

NJC003-031-NYC071-087-122056-
/O.CAN.KOKX.SV.W.0066.000000T0000Z-210812T2100Z/
Passaic NJ-Bergen NJ-Orange NY-Rockland NY-
448 PM EDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR PASSAIC...NORTHWESTERN
BERGEN...SOUTHERN ORANGE AND ROCKLAND COUNTIES IS CANCELLED...

The storms which prompted the warning have weakened. Therefore, the 
warning has been cancelled.

Additional thunderstorms continue to develop across southeastern 
Orange county. Locally heavy rain and gusty winds can be expected 
with this activity.

LAT...LON 4105 7446 4110 7449 4120 7437 4132 7460
      4133 7461 4123 7395 4115 7389 4112 7389
      4096 7418 4096 7428 4100 7430 4103 7442
      4102 7443
TIME...MOT...LOC 2045Z 263DEG 35KT 4130 7431 4105 7415 4089 7457 

$$

The office that day

Everything else NWS New York, NY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 8:32 PM EDTSpecial Weather StatementOKXWestchester28 min
Aug 11, 8:39 PM EDTAreal Flood AdvisoryOKXKings, New York, Queens, Richmond2 hr
Aug 11, 9:00 PM EDTSpecial Marine WarningOKX30 min
Aug 11, 9:01 PM EDTSpecial Weather StatementOKXKings, New York, Richmond29 min
Aug 11, 9:25 PM EDTSpecial Weather StatementOKXKings, Queens35 min
Aug 11, 9:27 PM EDTSpecial Marine WarningOKX33 min
Aug 12, 4:21 PM EDTSpecial Weather StatementOKXDutchess24 min
Aug 12, 4:39 PM EDTSpecial Weather StatementOKXBronx, New York51 min
Aug 12, 4:45 PM EDTSpecial Marine WarningOKX90 min
Aug 12, 4:53 PM EDTSpecial Weather StatementOKXRockland52 min
Aug 12, 5:04 PM EDTSevere Thunderstorm WarningOKXOrange, Putnam, Rockland, Westchester22 min
Aug 12, 5:20 PM EDTSpecial Weather StatementOKXNassau40 min
Aug 12, 5:53 PM EDTSpecial Weather StatementOKXSuffolk52 min

Nearby

Severe Thunderstorm Warnings in New York, 2021Severe Thunderstorm Warnings in New Jersey, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.