Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 241045
SPC MCD 241044
Mesoscale Discussion 0133
NWS Storm Prediction Center Norman OK
0444 AM CST Tue Jan 24 2017
Areas affected...Parts of northeastern New York...Vermont...New
Hampshire...and much of Maine
Concerning...Winter mixed precipitation
Valid 241044Z - 241645Z
SUMMARY...A mix of freezing rain, sleet, and snow will continue
moving northward across parts of northeastern New York, Vermont, New
Hampshire, and much of Maine this morning.
DISCUSSION...A nearly stacked cyclone just off the Delmarva
Peninsula as of 1030Z will continue moving northward/northeastward
off the New England coast this morning. A band of ongoing
precipitation across much of New england tied to low-level warm air
advection/ascent will also develop northward across most of Maine
through the morning hours. A 06Z sounding from GYX revealed an
elevated warm layer between 800-700 mb, supporting at least some
melting of frozen hydrometeors aloft. Latest surface observations
and recent local storm reports across the Mesoscale Discussion area
indicate freezing rain and sleet are the primary precipitation types
with the ongoing band. With continued low-level warm air advection
attendant to a strong (50-60+ kt) 850 mb easterly low-level jet,
freezing rain will probably become the primary precipitation type
across NH and much of Maine through the morning hours where a
shallow near-surface sub-freezing layer will likely remain in place.
Freezing rain rates in excess of 0.05 inch/hour may occur, with
higher rates possible in heavier bands. Some sleet accumulations
will be more probable on the northern/western fringes of the main
precipitation band where the elevated warm nose is not as strong.
Precipitation should end from south to north across the discussion
area as the overall system lifts northward/northeastward.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 42977379 43547452 44337477 45067453 45087169 45357144
45467092 45867056 46347033 46456905 46396770 45786766
45586731 44816683 44586716 44086822 43916874 43686960
43337041 42937074 42827269 42977379