Alert archive / New Jersey / Tornado Watches in 2018

Tornado Watch 394

October 2, 2018Greater Bridgeport Planning Region, Northwest Hills Planning Region, Connecticut; 6 counties in New Jersey; 6 counties in New York

The Storm Prediction Center issued this tornado watch at Oct 2, 2018, 4:57 PM EDT for Greater Bridgeport Planning Region, Northwest Hills Planning Region, Connecticut; 6 counties in New Jersey; 6 counties in New York. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Oct 2, 2018, 4:57 PM EDT (20:57 UTC)
Expired
Oct 3, 2018, 12:00 AM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Greater Bridgeport Planning Region, CT, Northwest Hills Planning Region, CT, Bergen County, NJ, Essex County, NJ, Morris County, NJ, Passaic County, NJ, Sussex County, NJ, Warren County, NJ, Dutchess County, NY, Orange County, NY, Putnam County, NY, Rockland County, NY, Ulster County, NY, Westchester County, NY

The radar

The Albany radar (KENX), 127 km from the middle of the area, began a volume at 21:00 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Oct 2, 5:28 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region20 min
Oct 2, 5:33 PM EDTTornado WarningOKXGreater Bridgeport Planning Region12 min
Oct 2, 6:43 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region47 min
Oct 2, 6:49 PM EDTFlash Flood WarningOKXOrange, Rockland, Westchester3 hr
Oct 2, 7:22 PM EDTSevere Thunderstorm WarningPHIWarren53 min
Oct 2, 7:23 PM EDTSevere Thunderstorm WarningPHISussex52 min
Oct 2, 8:38 PM EDTTornado WarningPHIMorris, Sussex22 min
Oct 2, 8:56 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren49 min
Oct 2, 10:13 PM EDTFlash Flood WarningOKXBergen2 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.0 hours before the alert went out and 131 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 2018-10-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2018-10-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 square meters per square second.193958Sfc1 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
54 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
563 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

982 
WWUS20 KWNS 022054
SEL4  
SPC WW 022054
CTZ000-NJZ000-NYZ000-030400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 394
NWS Storm Prediction Center Norman OK
455 PM EDT Tue Oct 2 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Western Connecticut
  Northern New Jersey
  Southeast New York

* Effective this Tuesday afternoon from 455 PM until Midnight
  EDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Near an effective warm front, at least some supercell
tornado risk will likely persist this evening, and potentially even
somewhat increase as winds just above the surface strengthen across
the region. Aside from a tornado risk, some hail/wind may also
occur.

The tornado watch area is approximately along and 30 statute miles
north and south of a line from 55 miles west southwest of
Poughkeepsie NY to 35 miles east southeast of Poughkeepsie NY. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU4).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 392...WW 393...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 27025.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 2, 3:10 PM EDTMesoscale DiscussionSPC2 hr
Oct 2, 7:24 PM EDTMesoscale DiscussionSPC81 min
Oct 2, 4:43 PM EDTMesoscale DiscussionSPCWarren2 hr
Oct 2, 2:55 PM EDTTornado WatchSPCSullivan8 hr
Oct 2, 4:05 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Livingston, Ontario and 5 more115 min

Nearby

Tornado Watches in New Jersey, 2018Tornado Watches in New York, 2018Tornado Watches in Connecticut, 2018Every tornado watch in 2018

Sources

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