ZCZC SPCSWOMCD ALL
ACUS11 KWNS 161849 
SPC MCD 161849 
MEZ000-NHZ000-162245-

Mesoscale Discussion 0075
NWS Storm Prediction Center Norman OK
1249 PM CST Tue Jan 16 2024

Areas affected...Much of interior Maine

Concerning...Heavy snow 

Valid 161849Z - 162245Z

SUMMARY...Heavy snow rates on the order of 1-2 inches per hour are
increasingly likely by 4-7 PM EST, and probably will linger further
into the evening, before spreading to the northeast of the region.

DISCUSSION...Downstream of a significant short wave impulse turning 
northeastward through the lower Great Lakes region, cyclogenesis is
underway along a surface frontal zone near the northern Mid Atlantic
through southern New England coast vicinity.  Associated large-scale
ascent is contributing to an expanding and intensifying
precipitation shield beneath cooling cloud tops inland of coastal
areas.

It appears that this will continue while overspreading the remainder
of northern New England through the balance of the afternoon, in
response to further strengthening of lower/mid-tropospheric warm
advection and forcing for upward vertical motion.  A general
consensus of latest model output indicates a more rapid deepening of
the surface cyclone will commence by 21-00Z, largely offshore,
across and northeast of the Cape Cod vicinity by 21-00Z.

Across the coastal plain into higher terrain of Maine, deep-layer
lift, becoming maximized within the mid-level layer favorably cold
for large dendritic ice crystal growth, is forecast to become
increasingly conducive to heavy snow rates around or above 1 inch
per hour by 21-22Z, if not earlier.  This will be aided by cold
thermodynamic profiles entirely below freezing, and supportive of
moderately large snow to liquid water equivalent ratios, as
low-level moisture advection off the Atlantic contributes to
increasing precipitable water content (.4 to .6 inches).  

Strengthening frontogentic forcing may contribute to bands of
heavier snow rates approaching 2 inches per hour, with the heavy
snow lingering through mid to late evening before diminishing and/or
spreading with the large-scale ascent northeast of the region.

..Kerr.. 01/16/2024

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

ATTN...WFO...CAR...GYX...

LAT...LON   45666715 44236966 43657102 44227114 45277053 46276909
            46776794 45666715 

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