Alert archive / New York / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 549
The Storm Prediction Center issued this severe thunderstorm watch at Nov 13, 2021, 12:27 PM EST for 4 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 13, 2021, 12:27 PM EST (17:27 UTC)
- Expired
- Nov 13, 2021, 6:34 PM EST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 65 kt
All 34 counties
Capitol Planning Region, CT, Greater Bridgeport Planning Region, CT, Lower Connecticut River Valley Planning Region, CT, Naugatuck Valley Planning Region, CT, Northeastern Connecticut Planning Region, CT, Northwest Hills Planning Region, CT, Southeastern Connecticut Planning Region, CT, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Bronx County, NY, Dutchess County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Suffolk County, NY, Westchester County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI
The radar
The Brookhaven radar (KOKX), 50 km from the middle of the area, began a volume at 17:27 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
- 20%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
23 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 13, 1:02 PM EST | Severe Thunderstorm Warning | OKX | Passaic | 47 min |
| Nov 13, 1:15 PM EST | Severe Thunderstorm Warning | PHI | Mercer, Middlesex, Somerset | 13 min |
| Nov 13, 1:26 PM EST | Severe Thunderstorm Warning | OKX | Bergen | 49 min |
| Nov 13, 1:48 PM EST | Severe Thunderstorm Warning | OKX | Bergen, Essex, Hudson, Passaic, Union | 42 min |
| Nov 13, 1:51 PM EST | Severe Thunderstorm Warning | PHI | Middlesex | 9 min |
| Nov 13, 2:04 PM EST | Severe Thunderstorm Warning | PHI | Monmouth, Ocean | 41 min |
| Nov 13, 2:09 PM EST | Severe Thunderstorm Warning | ALY | Northwest Hills Planning Region | 51 min |
| Nov 13, 2:22 PM EST | Severe Thunderstorm Warning | OKX | Kings, Nassau, Queens | 38 min |
| Nov 13, 2:53 PM EST | Tornado Warning | OKX | Nassau, Suffolk | 37 min |
| Nov 13, 3:20 PM EST | Tornado Warning | OKX | Suffolk | 25 min |
| Nov 13, 3:40 PM EST | Tornado Warning | OKX | Suffolk | 24 min |
| Nov 13, 3:57 PM EST | Tornado Warning | OKX | Suffolk | 18 min |
| Nov 13, 4:07 PM EST | Tornado Warning | OKX | Suffolk | 23 min |
| Nov 13, 4:09 PM EST | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 15 min |
| Nov 13, 4:18 PM EST | Severe Thunderstorm Warning | OKX | Suffolk | 27 min |
| Nov 13, 4:30 PM EST | Severe Thunderstorm Warning | OKX | Suffolk | 30 min |
| Nov 13, 5:01 PM EST | Severe Thunderstorm Warning | BOX | Northeastern Connecticut Planning Region | 26 min |
| Nov 13, 5:02 PM EST | Tornado Warning | BOX | Northeastern Connecticut Planning Region | 28 min |
| Nov 13, 5:08 PM EST | Tornado Warning | BOX | Bristol, Kent, Providence, Washington | 24 min |
| Nov 13, 5:12 PM EST | Severe Thunderstorm Warning | BOX | Bristol, Kent, Newport, Providence, Washington | 44 min |
| Nov 13, 5:17 PM EST | Severe Thunderstorm Warning | BOX | Providence | 7 min |
| Nov 13, 5:21 PM EST | Tornado Warning | BOX | Providence | 24 min |
| Nov 13, 5:26 PM EST | Severe Thunderstorm Warning | BOX | Providence | 32 min |
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, 5.5 hours before the alert went out and 50 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1435 m above ground
- 0-6 km bulk shear
- 82 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
105
WWUS20 KWNS 131724
SEL9
SPC WW 131724
CTZ000-NJZ000-NYZ000-RIZ000-CWZ000-140000-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 549
NWS Storm Prediction Center Norman OK
1225 PM EST Sat Nov 13 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Connecticut
Northern New Jersey
Southeast New York
Rhode Island
Coastal Waters
* Effective this Saturday afternoon and evening from 1225 PM
until 700 PM EST.
* Primary threats include...
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible
SUMMARY...An intensifying line of thunderstorms over northern New
Jersey will track eastward across the watch area this afternoon,
posing a risk of damaging wind gusts and isolated hail.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 25 miles west northwest
of Newark NJ to 25 miles southeast of Providence RI. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 65 knots. A few
cumulonimbi with maximum tops to 400. Mean storm motion vector
26035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 13, 12:07 PM EST | Mesoscale Discussion | SPC | 113 min | |
| Nov 13, 2:06 PM EST | Mesoscale Discussion | SPC | 84 min | |
| Nov 13, 4:09 PM EST | Mesoscale Discussion | SPC | Barnstable, Bristol, Dukes, Norfolk, Plymouth, Suffolk | 2 hr |
Nearby
Severe Thunderstorm Watches in New York, 2021Severe Thunderstorm Watches in New Jersey, 2021Severe Thunderstorm Watches in Connecticut, 2021Every severe thunderstorm watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.