Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 210432
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1132 PM EST Mon Feb 20 2017

.SYNOPSIS...
High pressure will crest over the area tonight before gradually
shifting on Tuesday. A warm front approaches from the west
Tuesday night and early Wednesday bringing some light
precipitation to the region. Temperatures will be on the
increase for the remainder of the week with a few chances for
showers mainly over the mountains. A more substantial system
arrives for the weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Update...
Have updated grids based on current observations and latest set
of mesoscale models. Northwest winds continue to bring in cooler
and drier air into Northern New England. Expect clear skies with
diminishing winds and radiational cooling after midnight
tonight. However, to this point late this evening, dew points
have not lowered sufficiently to consider widespread below zero
readings for overnight lows over the northern mountains. May be
nudging a few of our normally colder locations using the
PFM/Serp tool and have adjusted mins a few degrees downwards
from their current forecast, especially over northern/mountain
regions.

Adjusted winds and current dew points. Otherwise, the rest of
the forecast package will remain relatively unchanged.

Prev Disc...
Downsloping winds have cleared out cloud cover and
allowed for another nice day despite being much cooler than we
were yesterday. We are still above normal with a somewhat gusty
NW flow in place. Tonight`s temperatures were a mix of short
term meso guidance taking into account some weak cold air
advection, clear skies, and winds going nearly calm overnight in
many spots as high pressure crosses to the Atlantic. The
valleys and other drainage areas will cool off quickly and we
will see spots below 10 degrees in the mountains by morning.
Elsewhere teens are expected.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
High pressure will shift east on Tuesday as a warm front
approaches from the west. In a very dry air mass we will have
another quick warm up tomorrow with highs in the mid 30s to mid
40s...a pretty large diurnal jump with the sun angle increasing
each day. After a mostly sunny start to the day high clouds will
overspread the region during the afternoon.

Warmer air arrives Tuesday night/Wednesday morning as
temperatures drop below freezing at the surface. This weak
overrunning pattern will create some areas of light wintry
precipitation. The main concern will be a few hundredths of
freezing rain which may fall towards morning mainly in the
mountains and perhaps downstream over the coastal plain. Again
this looks like a rather low impact event but may bring some
impacts as far as slick driving surfaces.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A warm zonal flow develops midweek. Models move a strong short
wave through the midwest Thursday and into the Great Lakes
by Saturday. In advance of this trof ridging and even warmer
temps are expected for Thursday and Thursday night. By Friday
a warm front will move north across the region as an increasing
southerly flow develops to the east of the approaching trof.
Some light precipitation is possible as this warm front moves
north across the region. Friday night and Saturday will remain
mild and went a little above guidance temps. The approaching
upper trof will move east across southeast Canada late Saturday
with a trailing cold front and associated showers that will
continue into Saturday night.

A return to a colder northwest flow will develop by Sunday.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Short Term...VFR today through Tuesday with increasing cloud
cover and possibly some MVFR decks very late Tuesday.

Long Term...VFR conditions generally expected through the end of
the week. A low pressure system cutting thru the Great Lakes
will push a warm front thru the area Fri. This will likely bring
an extended period of MVFR or lower. MVFR conditions in
scattered showers will continue Saturday due to an approaching
cold front.

&&

.MARINE...
Short Term...Winds will decrease from west to east overnight as
high pressure shifts towards the coast. Have dropped SCAs.

Long Term...Winds and seas expected to remain below SCA
thresholds thru the end of the week.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$
NEAR TERM...Cannon
SHORT TERM...Cannon
LONG TERM...Cannon


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