Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
1142 PM EST Monday Feb 8 2016
low pressure will exit into the Canadian Maritimes later tonight.
Another low will form off the middle Atlantic coast and move toward
Cape Cod on Tuesday. The result will be widespread snowfall across
the region. A broad trough of low pressure will slowly move across
the area Wednesday and Thursday and exit by Friday. This trough
will be followed by much colder air Friday and into the weekend.
Near term /until 6 am Tuesday morning/...
1140 PM...minor estf update to reflect current radar trend and to
ingest the 04z mesonet into near term grids. Winds continue to
drop off on the waters and the gale has been replaced with a small
craft with this update. High tide was a short time ago with an
anomaly of 1.7 feet. This put the tide about 0.5 feet below flood
stage. However...with seas between 12 and 14 feet at the near shore
buoys there should be some splashover and beach erosion for the
next hour or so.
a band of moderate to heavy snow has formed over the eastern
portion of our forecast area...basically from Portland and points
north and east per latest radar imagery. Expect this band to
continue in this region until about 04z or 05z before weakening
which is in line with the last hrrr model. Will monitor some of
these areas for high snowfall totals and possible additional
warnings over the next hour.
The snow has retrograded all the way to the Vermont border with snow
now begin reported in most areas except perhaps Central Somerset
Previous disc... have updated the grids based on current observations
and latest suite of mesoscale models. Snow has finally spread into
central/southern New Hampshire and central Maine this evening as
bands of moisture continue to rotate westward around the periphery
of the intense offshore low. Inverted trough also acting as a
focus for the precipitation this evening.
Dry air is diminishing the precipitation further to the north with dew
points very low at this hour at the surface. Have adjusted area
for the region of moderate to heavy snow and blowing snow to be
focused over southern sections.
impressive low pressure system well out to sea continues to loft
moisture towards the eastern Seaboard. Another low pressure system
over the eastern Great Lakes will move closer to New England by
tomorrow. These surface reflections as well as the upper level
trough overhead was providing enough forcing for ascent for
widespread light to moderate snowfall across the region.
Earlier this morning the precipitation shield had a hard time
moving northward due to evaporation on the northern edge. A very
dry airmass in place kept any snow from falling until about 3-4
hours ago. Several snow bands have now emerged along pettersson
frontogenesis maxima. One band in particular is currently rotating
nearly parallel to the New Hampshire/ME coastline.
To the north...zero or subzero dew points persist with north
winds continually drawing drier air southward. This fact will
keep snow evaporating into virga for a few more hours across the
north before top down saturation occurs.
Winds are gusting into the upper 20s to middle 30s. This trend will
continue through about midnight before they diminish somewhat.
This combined with a very dry fluffy snow will create blowing and
drifting snow. Due to this reduced visibilities are expected this
evening and tomorrow morning especially closer to the coast.
Winter storm warnings have been expanded down the coast to
include Portland and also southwest and inland to include
Rockingham County and east Hillsborough County.
Overnight lows should range from the single digits north to the
upper teens south.
Short term /6 am Tuesday morning through Tuesday night/...
expect accumulations to hover in the 6-8 inch range in warned
areas through Tuesday. The remainder of the region is under a
Winter Weather Advisory. Most of the snow over southern New Hampshire and SW
Maine will fall before 6 am Tuesday. As the band fills in
downeast... more locations may need to be added. Looking at the
fluff factor we could even see some areas of the mountains
requiring a warning before all is said and done.
Tuesday highs will be in the lower 20s north to upper 20s south.
Snow will taper off by middle morning across the region as the
strongest low pressure system moves quickly east. Residual
troughiness will keep flurries around with the chance of snow
showers lingering for the highest peaks. Tomorrow night
temperatures will be similar to tonight. Clouds stick around with
no front to scour out the moisture.
Long term /Wednesday through Monday/...
deep upper trough slowly pivots across northern New England Wednesday and
Thursday and exits the region on Friday. With the upper trough there will be
plenty of instability so scattered snow showers are expected
especially in the mountains. Several inches of accumulations are
likely for the mountains. On Friday the trough exits but then it will
be followed by a strong Arctic cold front as a cold polar upper
vortex drops into New England bringing by far the coldest air of
the season with gusty winds. Scattered snow showers and bitter
cold can be expected through the weekend into early next week.
Stayed close to the superblend models for temperatures but raised probability of precipitation
for Wednesday/Thursday period.
Aviation /06z Tuesday through Saturday/...
short term...VFR conditions will give way to gradually lowering
ceilings and light snow by early afternoon. Occasional IFR
conditions will be possible by late today. NE winds will increase
and gust to 25 or 30 knots near the coast with lower speeds
inland...before diminishing tonight. Areas of MVFR Tuesday in snow
Long term...upper trough pivots over the region through Thursday...with
areas of shsn likely. Local IFR conditions are possible in any
shsn...and they will be possible at any terminal. Strong cold fnt
approaches the area Friday with gusty northwest winds.
short term...winds and seas will build through tonight. Gales
remain in place as ocean low passes by to our southeast.
Conditions drop below gales around midnight with lingering small
craft conditions outside the bays for Tuesday.
Long term...extended period of Small Craft Advisory conditions appears likely through
the end of the week. Winds will be light for Wednesday and Thursday with seas
remaining above 5 feet over the outer waters but slowly subsiding. A
strong cold fnt will approach the waters for the weekend...with
gusty northwest winds expected.
a 1 to 1.5 foot storm surge will combine with high astronomical
tides and seas of 10 to 15 feet tonight into Tuesday morning. A
coastal Flood Advisory has been issued for coastal
York...Rockingham...and Cumberland counties for this evenings high
tide around 11 PM. For tomorrow mornings high tide around 11
am...a higher tide required a coastal Flood Warning. Both of these
tides may lead to minor coastal flooding or splash-over along the
coasts of York...Rockingham...and Cumberland counties. See cfwgyx
for more information. Wave periods expected to peak at around 13
seconds tomorrow morning...with high energy swells striking the
ME...Winter Weather Advisory until 8 am EST Tuesday for mez007>009-
Coastal Flood Warning from 9 am to 1 PM EST Tuesday for mez023-
Winter Storm Warning until 8 am EST Tuesday for mez023-024.
Coastal Flood Advisory until 1 am EST Tuesday for mez023-024.
New Hampshire...Winter Weather Advisory until 6 am EST Tuesday for nhz003>011-
Winter Weather Advisory until 8 am EST Tuesday for nhz001-002.
Winter Storm Warning until 6 am EST Tuesday for nhz012>014.
Coastal Flood Warning from 9 am to 1 PM EST Tuesday for nhz014.
Coastal Flood Advisory until 1 am EST Tuesday for nhz014.
Marine...Small Craft Advisory until 1 PM EST Tuesday for anz150>154.