Severe Storm Outlook Narrative (AC)
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ACUS11 KWNS 121952
SPC MCD 121951

Mesoscale Discussion 0172
NWS Storm Prediction Center Norman OK
0151 PM CST Sun Feb 12 2017

Areas affected...Portions of eastern NY...VT...NH...MA...Maine

Concerning...Heavy snow

Valid 121951Z - 130015Z

SUMMARY...Areas of heavy snow with rates of 1.0-1.5 inches per hour
will continue spreading east-northeastward across portions of
eastern New York and New England through the remainder of the
afternoon and into the early evening hours.

DISCUSSION...A broad shield of precipitation being enhanced by
elevated warm advection and frontogenesis, well in advance of an
amplifying midlevel shortwave trough crossing the Great Lakes
region, is spreading east-northeastward across parts of the
Northeast. Related ascent extends through sufficiently deep
dendritic growth zones for heavy snow, with heavy snow presently
being reported across portions of eastern NY and southern New

The zone of isentropic ascent and related areas of heavy snow will
continue to spread east-northeastward across the region, with
1.0-1.5-inch/hour snow rates anticipated. Linear extrapolation and
the latest short-range high-resolution model guidance suggest that
the leading edge of heavier snow should enter parts of
western/southern Maine around 21Z, with this activity continuing to
spread east-northeastward into the early evening hours.

Meanwhile, midlevel dry air should continue impinging on the
southern extent of the precipitation shield. This will result in
lessening intensity/coverage of snow across parts of east-central NY
and adjacent southern New England through the early evening, while
heavy-snow potential continues farther north/northeast.

..Cohen.. 02/12/2017

...Please see for graphic product...


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