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SPC MD 223

MD 0223 CONCERNING HEAVY SNOW FOR PARTS OF THE CATSKILLS AND CAPITAL DISTRICT OF NEW YORK INTO THE MOUNTAINS OF SOUTHERN/EASTERN VERMONT...NORTHERN NEW HAMPSHIRE AND NORTHWESTERN MAINE
MD 0223 Image


Mesoscale Discussion 0223
NWS Storm Prediction Center Norman OK
0429 AM CDT Fri Mar 22 2019

Areas affected...Parts of the Catskills and Capital District of New
York into the mountains of southern/eastern Vermont...northern New
Hampshire and northwestern Maine

Concerning...Heavy snow 

Valid 220929Z - 221330Z

SUMMARY...A narrow band of heavy snow, including rates of 1-2+
inches per hour, is expected to continue to develop across the
region and persist through the 10 am to Noon EDT time frame.

DISCUSSION...A fairly deep, occluded surface cyclone has migrated
off the New Jersey coast, and is forecast to continue
eastward/northeastward, to the south of Long Island, through
daybreak, before a secondary low begins to form across the Cape Cod
vicinity by late morning.
As this occurs, models indicate the continued evolution of a
lower/mid tropospheric deformation zone across the Catskills and
Capital District of New York, into the mountains of northern New
Hampshire and northwestern Maine, through the 14-16Z time frame.

Associated frontogenetic forcing is forecast to support
strengthening lift in the mixed-phase layer favorable for large
dendritic ice crystal growth.  This may already be underway in a
corridor from the Catskills into the Green Mountains. Although
low-level thermodynamic profiles across this region still appear
mostly above freezing, diabatic cooling, perhaps coupled with weak
low-level cold advection as near-surface winds turn to northerly,
probably will support a transition to heavy snow by daybreak.

In the presence of fairly moist conditions (precipitable water .5 to
.6+ inches), the Rapid Refresh, among other model output, indicates
heavy snow rates of 1-2+ inches per hour are possible, and may
persist for at least a 3-4 hour period at any one location, while
developing northeastward into the mountains of northwestern Maine by
late morning.

..Kerr.. 03/22/2019

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

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

LAT...LON   41937484 42867430 43777295 44657174 45307054 45846996
            45306928 44347065 43237236 42407337 41987408 41537463
            41937484 

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