Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 250305 AAB

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1105 PM EDT Mon Oct 24 2016

Low pressure meandering over the maritimes will provide a brisk
westerly flow over the region through Tuesday, with some upslope
snow accumulations expected in the mountains. High pressure will
gradually build in from the northwest Wednesday and Wednesday
night. Low pressure will approach from the west on Thursday and
will cross the region Thursday night and Friday with some wintry
precipitation in the mountains and rain elsewhere. More rain is
possible later in the weekend.


Update...It is a pretty classic upslope snow shower look to the
radar this evening. With Froude numbers above 1...and model
forecasts to stay that way thru morning...I have added some
flurries to areas S of the mtns. I do not expect enough snow to
see any accumulations in those areas...but enough to see the first
flakes for many tonight. N of the mtns...the forecast remains
unchanged with snow showers continuing thru morning. I have upped
the PoP at the higher elevations...with high chance to likely PoP
for valley locales.

Previous discussion...At 18z...a 990 millibar low was centered
vicinity of the Gaspe Peninsula. A brisk westerly flow continued
around this low across northern New England. GOES visible imagery
showed broken to overcast clouds in the cool cyclonic flow around
the associated upper low with a bit more sunshine across southeast
New Hampshire into adjacent southwest coastal Maine. Temperatures
ranged from 40s in the mountains to lower and mid 50s over the
southern half of New Hampshire and southwest coastal Maine. NWS
Doppler radar mosaic was indicating scattered light return across
the mountains where there are widely scattered sprinkles or
flurries occurring largely dependent on boundary layer
temperatures and elevation. For tonight...the vertically stacked
disturbance to our north will meander a bit further south while
several weak impulses rotate around it. clouds will spread further
south and east overnight with some upslope rain and snow showers
across the higher terrain. The terrain above 1500 feet vicinity of
the international border could see an inch or two of wet snow
overnight with little if any expected at lower elevations. Lows
will be in the 30s.


Tuesday will get breezy again, although a little less so than
today. While upslope rain and snow showers will diminish in
coverage, they will continue throughout the day, with some light
accumulation still possible in the higher terrain. Some sunshine can
be expected in the downslope on the coastal plain with highs a
couple degrees cooler than today on average. Becoming Partly to
mostly clear along the coastal plain Tuesday night...while clouds
linger elsewhere in the persistent cool cyclonic flow. A few
lingering upslope Snow showers are possible across the higher
terrain. Lows Tuesday night will range from the upper 20s to lower
30s. With a bit less wind tomorrow night...we may finally be able
to officially end the growing season in coastal York and
Rockingham counties.


Cool cyclonic flow will remain over the region on Wednesday
providing for brisk and chilly weather. More clouds than sun is
expected, especially across northern zones.

A cold night is expected Wednesday night as high pressure moves
over the region. Northeastern zones may hold onto some clouds
throughout the night and would allow temps to not go as low there.
However, southern and western zones should see clearing skies and
lows in the 20s over a pretty widespread area.

A short wave trough and associated sfc low pressure and warm front
will approach early on Thursday. Forcing for ascent will increase
from SW to NE across NH during the day Thursday, and will then
push across the entire CWA thursday night. The antecedent air mass
will likely be cold enough across portions of central and northern
NH as well as the western ME mountains to allow for accumulating
snow later Thursday afternoon and night. Depending on how cold the
column is and how much ascent develops to allow for significant
cooling through melting and also evaporation, some lower
elevations across SW/W NH may also see some snowflakes and perhaps
a light coating of snow. The rest of the region should see rain
due to warming boundary layer temperatures. There`s an outside
chance that a couple of zones in NH and potentially the western ME
mountains need an advisory for Thu night for snowfall.
Thereafter, the column may warm enough to allow to a transition to
all rain most everywhere. The rain could be heavy at times,
especially Friday morning.

Thereafter, a couple of weaker systems may affect the area late
Saturday and Saturday night, with another possibly bringing more
rain later Sunday and Sunday night.


Short Term /through Tuesday night/...VFR. Lcl MVFR psb tonight and
Tue in mtn -shsn. NW sfc wind with gusts up to 25 kt through 22z
Today before diminishing.

Long Term...MVFR /IFR Ceilings developing Thursday Afternoon from
west to east, possibly holding off until nighttime on the coastal
plain and western ME mountains. IFR/LIFR ceilings/vsby Thursday
night and Friday in rain (snow in the mountains).


Short Term /through Tuesday night/...Little change as the brisk
circulation continues around the stalled low over eastern Canada.
Small Craft conditions will continue tonight into Tuesday night outside
the bays.

Long Term...Small craft conditions likely Thursday night and
Friday, with the possibility of low-end gales during that period


MARINE...Small Craft Advisory until 8 PM EDT Tuesday for ANZ150-152-154.



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