Mesoscale Discussion 0119
NWS Storm Prediction Center Norman OK
1242 PM CDT Tue Mar 13 2018
Areas affected...Long Island and coastal New England
Valid 131742Z - 132015Z
CORRECTED TYPO/WORDING IN DISCUSSION
SUMMARY...Heavy snow rates, at times on the order of 2-3+ inches per
hour within a couple of narrow bands, appear in the process of
peaking across parts of Long Island and southeastern New England
early this afternoon. This may begin to diminish by 2-3 PM EDT, but
1 inch per hour snow rates may linger within a corridor across
southern coastal Maine/New Hampshire and the Boston metro area
through 5-6 PM EDT.
DISCUSSION...To the southeast of Cape Cod, the center of the deep
surface cyclone appears in the process of redeveloping eastward,
much as indicated by the latest Rapid Refresh, before it migrates
northeastward toward areas near/southeast of the Novia Scotia coast
by early evening. As this occurs, one narrow but persistent heavy
snow band extending from the Vermont/New Hampshire border area into
central and eastern Long Island may diminish within the next few
hours, while snow rates within the primary band to the east peak
across parts of eastern Connecticut/Rhode Island into the Boston
metropolitan area and coastal southern Maine between now and 18-19Z.
Thereafter, lower/mid tropospheric frontogenetic forcing is forecast
to weaken. However, lift within the dendritic growth layer
(supported by lower/mid-level warm advection) may remain strong
enough to maintain sustained lingering heavy snow rates in excess of
1 inch per hour across the Boston metro and coastal southern Maine
through at least 21-22Z.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 43506988 42407059 41617141 40867217 41457224 42467168
42887125 43937054 44396987 44466906 44066866 43506988