Alert archive / Vermont / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 57

March 26, 202110 counties in New York; 11 counties in Vermont

The Storm Prediction Center issued this severe thunderstorm watch at Mar 26, 2021, 11:11 AM EDT for 10 counties in New York; 11 counties in Vermont. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2021, 11:11 AM EDT (15:11 UTC)
Expired
Mar 26, 2021, 3:50 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 21 counties

Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Saratoga County, NY, St. Lawrence County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Chittenden County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 50 km from the middle of the area, began a volume at 15:13 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
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 26, 11:29 AM EDTSevere Thunderstorm WarningALYHamilton, Herkimer46 min
Mar 26, 11:30 AM EDTSevere Thunderstorm WarningBTVEssex, Franklin, St. Lawrence45 min
Mar 26, 12:13 PM EDTSevere Thunderstorm WarningBTVClinton, Essex, Franklin, St. Lawrence47 min
Mar 26, 12:16 PM EDTSevere Thunderstorm WarningALYHamilton, Herkimer, Warren44 min
Mar 26, 1:11 PM EDTSevere Thunderstorm WarningBTVClinton, Essex49 min
Mar 26, 1:57 PM EDTSevere Thunderstorm WarningBTVAddison, Caledonia, Chittenden, Orange, Rutland, Washington and 1 more48 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

Albany, NY (KALY), launched 12:00Z, 3.2 hours before the alert went out and 166 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, Albany, NY at 12:00Z on 2021-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Albany, NY at 12:00Z on 2021-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 202 square meters per square second.1939587897Sfc1 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
2 J/kg
Mixed-layer CIN
-438 J/kg
Mixed-layer LCL
578 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
202 m²/s²
0-3 km storm-relative helicity
311 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

844 
WWUS20 KWNS 261507
SEL7  
SPC WW 261507
NYZ000-VTZ000-262000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 57
NWS Storm Prediction Center Norman OK
1110 AM EDT Fri Mar 26 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Upstate New York
  Much of Vermont

* Effective this Friday morning and afternoon from 1110 AM until
  400 PM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Short bands of fast-moving thunderstorms are expected to
move across upstate New York and into Vermont through the afternoon,
with the potential to produce damaging winds.

The severe thunderstorm watch area is approximately along and 65
statute miles east and west of a line from 40 miles north northeast
of Saranac Lake NY to 20 miles south southwest of Glens Falls NY.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU7).

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
0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 400. Mean storm motion vector
25045.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 10:13 AM EDTMesoscale DiscussionSPCClinton, Essex, Franklin, Hamilton, Herkimer, Jefferson and 4 more2 hr
Mar 26, 1:33 PM EDTMesoscale DiscussionSPCSaratoga, Washington87 min

Nearby

Severe Thunderstorm Watches in Vermont, 2021Severe Thunderstorm Watches in New York, 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.