MD 0214 CONCERNING HEAVY SNOW FOR PARTS OF NORTHERN NEW HAMPSHIRE INTO WESTERN MAINE
Mesoscale Discussion 0214
NWS Storm Prediction Center Norman OK
1027 PM CST Sat Mar 09 2024
Areas affected…parts of northern New Hampshire into western Maine
Concerning…Heavy snow
Valid 100427Z – 100930Z
SUMMARY…Sustained heavy snow appears most likely to become focused
across the mountains of northern New Hampshire into northwestern
Maine overnight into daybreak Sunday, including hourly rates
increasing to 1-2+ inches per hour.
DISCUSSION…A developing surface cyclone appears to be undergoing a
period of more rapid deepening as it migrates across the northern
Mid Atlantic region toward southern New England. Strengthening
deep-layer ascent to the north-northeast of this feature, supported
by lower/mid-tropospheric warm advection beneath an increasingly
difluent and divergent upper flow field, is in the process of
overspreading much of eastern New York and western New England,
accompanied by moderate to heavy precipitation.
Thermodynamic profiles near or below freezing are generally focused
across the higher terrain, and with further low-level warming, may
become increasingly confined to the mountains of northern New
Hampshire into northwestern Maine overnight. This is where ensemble
output (including the latest NCEP SREF and HREF) suggest highest
probabilities for heavy snow rates developing and being maintained,
perhaps at rates in excess of 2 inches per hour by 09-12Z.
It appears that precipitable water within the saturating,
sub-freezing profiles across this region may increase up to around
.70 inches. Rapid Refresh forecast soundings indicate that this
will coincide with a period of intensifying lift within a layer
between roughly 600-500 mb, where the environment will become most
conducive to large dendritic ice crystal growth with temperatures
around -15 C. It appears that a fairly deep layer layer through the
lowest few kilometers above ground level may become characterized by
isothermal profiles near freezing, contributing to potential for
considerable continuing snow flake growth via aggregation before
reaching the surface as a “heavy, wet” snow.
..Kerr.. 03/10/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…GYX…
LAT…LON 45247007 44937001 44097102 43867142 44037185 44787129
45567048 45247007
