Alert archive / New York / Mesoscale Discussions in 2021

Mesoscale Discussion 2057

December 25, 20214 counties in New Hampshire; 13 counties in New York; 6 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Dec 25, 2021, 5:44 PM EST for 4 counties in New Hampshire; 13 counties in New York; 6 counties in Vermont. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Dec 25, 2021, 5:44 PM EST (22:44 UTC)
Expired
Dec 25, 2021, 9:45 PM EST
In force
4 hr
Issued by
the Storm Prediction Center
Concerning
Freezing rain
All 23 counties

Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH, Essex County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Montgomery County, NY, Oneida County, NY, Oswego County, NY, Saratoga County, NY, Schenectady County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Orange County, VT, Rutland County, VT, Windham County, VT, Windsor County, VT

The radar

The Ft Drum radar (KTYX), 112 km from the middle of the area, began a volume at 22:44 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 nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 10.7 hours before the alert went out and 325 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, Gray, ME at 12:00Z on 2021-12-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Gray, ME at 12:00Z on 2021-12-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1068 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
289 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

683 
ACUS11 KWNS 252244
SWOMCD
SPC MCD 252244 
NHZ000-VTZ000-NYZ000-260245-

Mesoscale Discussion 2057
NWS Storm Prediction Center Norman OK
0444 PM CST Sat Dec 25 2021

Areas affected...Northern New York and southern Vermont and New
Hampshire

Concerning...Freezing rain 

Valid 252244Z - 260245Z

SUMMARY...Freezing rain will be possible this evening across
northern New York and southern Vermont and New Hampshire.
Accumulations up to 0.05" per hour are possible.

DISCUSSION...Surface observations from northern NY and southern
NH/VT have reported light freezing rain over the past hour, with
accumulations on the order of 0.03 inches per hour for some
locations. A shallow sub-freezing layer noted in recent surface
obs/RAP mesoanalysis is not being assimilated well into recent
guidance and may support freezing rain through the remainder of the
afternoon as light precipitation over northwest NY shifts east.
Given the weak nature of the ascent over the region (primarily
associated with a transient upper-level wave), precipitation rates
should not increase appreciably. Regardless, freezing rain
accumulations as high as 0.05 inches/hour may occur through late
afternoon and evening hours.

..Moore/Marsh.. 12/25/2021

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

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

LAT...LON   44077627 44467595 44457433 44287269 44027207 43337148
            42837171 42817352 42827480 43137599 43447643 44077627

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 25, 5:44 AM ESTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Grafton, Hillsborough, Merrimack and 3 more5 hr

Nearby

Mesoscale Discussions in New York, 2021Mesoscale Discussions in Vermont, 2021Mesoscale Discussions in New Hampshire, 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.