Alert archive / New York / Mesoscale Discussions in 2019

Mesoscale Discussion 39

January 20, 20199 counties in New Hampshire; 21 counties in New York; 14 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Jan 20, 2019, 12:46 AM EST for 9 counties in New Hampshire; 21 counties in New York; 14 counties in Vermont. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jan 20, 2019, 12:46 AM EST (05:46 UTC)
Expired
Jan 20, 2019, 4:45 AM EST
In force
4 hr
Issued by
the Storm Prediction Center
All 44 counties

Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Strafford County, NH, Sullivan County, NH, Cayuga County, NY, Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Oswego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, St. Lawrence County, NY, Warren County, NY, Washington County, NY, Wayne County, NY, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 82 km from the middle of the area, began a volume at 05:50 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

Albany, NY (KALY), launched 00:00Z, 5.8 hours before the alert went out and 128 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 00:00Z on 2019-01-20Temperature 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, Albany, NY at 00:00Z on 2019-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 339 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
502 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
339 m²/s²
0-3 km storm-relative helicity
428 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

268 
ACUS11 KWNS 200547
SWOMCD
SPC MCD 200546 
MEZ000-NHZ000-VTZ000-MAZ000-NYZ000-200945-

Mesoscale Discussion 0039
NWS Storm Prediction Center Norman OK
1146 PM CST Sat Jan 19 2019

Areas affected...Northern NY...VT...NH...Far Southwest ME

Concerning...Heavy snow 

Valid 200546Z - 200945Z

SUMMARY...Widespread snowfall rates from 1-2"/hr are anticipated
with localized rates above 2"/hr possible.

DISCUSSION...A maturing mid-latitude cyclone continues to move
eastward across the OH Valley with a large area of moderate to
occasionally heavy snow ahead of this system across PA and much of
NY. Expectation is for this large precipitation shield to expand
northward into northern NY, VT, and NH over the next several hours.
At the same time, low-level winds within the warm conveyor are
expected to strengthen slightly as the system matures, resulting in
an increase of the warm-air advection ahead of the cyclone.
Consequently, a large area of moderate to heavy snow will develop
from northern NY eastward across VT, NH, and into far southwest ME.
Given the strength of the warm-air advection/frontogenesis,
widespread snowfall rates of 1-2"/hr are anticipated with localized
areas experiencing rates above 2"/hr.

..Mosier.. 01/20/2019

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

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

LAT...LON   44407585 44897516 45017434 45037195 44827114 44487075
            43947074 43287089 42977128 42777181 42657234 42617353
            42867656 43217750 43817691 44407585

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 20, 6:42 AM ESTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Coos, Grafton, Hillsborough and 4 more6 hr
Jan 20, 1:01 PM ESTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Coos, Grafton, Hillsborough and 4 more4 hr
Jan 19, 9:33 PM ESTMesoscale DiscussionSPCAllegany, Bronx, Broome, Cattaraugus, Chautauqua, Chemung and 11 more3 hr

Nearby

Mesoscale Discussions in New York, 2019Mesoscale Discussions in Vermont, 2019Mesoscale Discussions in New Hampshire, 2019Every mesoscale discussion in 2019

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.