Alert archive / New York / Mesoscale Discussions in 2021

Mesoscale Discussion 271

March 26, 202110 counties in New York; 6 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2021, 10:13 AM EDT for 10 counties in New York; 6 counties in Vermont. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2021, 10:13 AM EDT (14:13 UTC)
Expired
Mar 26, 2021, 12:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%

Counties Clinton County, NY, Essex County, NY, Franklin County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Oneida County, NY, Oswego County, NY, St. Lawrence County, NY, Addison County, VT, Chittenden County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Washington County, VT

The radar

The Ft Drum radar (KTYX), 86 km from the middle of the area, began a volume at 14:14 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 2.2 hours before the alert went out and 157 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°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.

762 
ACUS11 KWNS 261414
SWOMCD
SPC MCD 261413 
VTZ000-NYZ000-261615-

Mesoscale Discussion 0271
NWS Storm Prediction Center Norman OK
0913 AM CDT Fri Mar 26 2021

Areas affected...parts of northern New York into Vermont

Concerning...Severe potential...Watch possible 

Valid 261413Z - 261615Z

Probability of Watch Issuance...40 percent

SUMMARY...Scattered storms are expected to develop by midday, and a
few could produce localized wind damage. A brief tornado will also
be possible.

DISCUSSION...A deep surface low will move rapidly east from Lake
Ontario across northern NY, with a trailing cold front and dryline.
Meanwhile, a warm front will continue to lift north across VT and
NH, along with mid to upper 50s F dewpoints.

Visible imagery shows areas of heating ahead of the cold front
across central NY, along with strong wind gusts across the warm
sector as the boundary layer mixes. Further clearing is possible
behind the warm front, which will allow for destabilization across
the remainder of northern NY, VT, and into NH.

Forecast soundings from various models indicate that sufficient
SBCAPE will develop to support at least isolated severe storms, with
damaging wind gusts most probable with storms forming ahead of the
low. A supercell or two will be possible as well, especially if
destabilization can occur near the warm front where low-level winds
may remain backed. Otherwise, the strong mixing points west should
result in mainly straight hodographs.

..Jewell/Thompson.. 03/26/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BTV...ALY...BGM...BUF...

LAT...LON   43487421 43127545 43187607 43507632 44057612 44377600
            45087499 45057238 44427233 43927306 43487421

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 11:11 AM EDTSevere Thunderstorm WatchSPCClinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 4 more5 hr
Mar 26, 1:33 PM EDTMesoscale DiscussionSPCSaratoga, Washington87 min

Nearby

Mesoscale Discussions in New York, 2021Mesoscale Discussions in Vermont, 2021Every mesoscale discussion 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.