Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
000
FXUS61 KGYX 030015
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
715 PM EST Thu Dec 2 2021

.SYNOPSIS...
A cold front will cross the area tonight and help to change
any precipitation back to snow showers. Some of these may be
heavy in the mountains. Near normal temperatures but gusty winds
will follow for Friday. The weekend will be mainly dry and
seasonably cool, with a chance for show showers Saturday night.
Low pressure passes to our west on Monday, and that will bring
mainly rain to the region Monday.

&&

.NEAR TERM /TONIGHT/...
715 PM Update... Quick update to add isolated thunder for
southern New Hampshire this evening. Pulses have blossomed
somewhat along the convective line of showers marking the cold
front, all the way into the Greens of Vermont. Though it has
been coming down in the latest few radar scans... still think a
stray spike can happen. Along with adding a couple hours of
isolated thunder mention... revamped PoPs to better reflect bad
of prefrontal showers exiting to the east and incoming
convective line with a relative lull separating the two.

600 PM Update... Made a few minor changes to the temperature
forecast through this evening to pull it better in line with
observed trends. Temperatures continue to be tough to warm over
the interior of western Maine, staying steady within a couple
degrees of freezing. Toward the west is an approaching cold
front with even some weak convection and thunderstorm activity
is tracking across the NY Thruway; when that reaches here later
in the evening into overnight I don`t expect storm activity but
it will bring better mixing and gusty winds. Have upped gusts a
bit overnight and did a general refresh of the wind forecast to
pull in some downsloping gusts as well using hires model input.

Previously... A closed low pressure system is currently moving
northeastward through Quebec. There remains a large gradient in
temperature this afternoon across the area with coastal
locations now well into the 40s to even lower 50s while across
portions of the foothills CAD has kept temperatures near the
freezing mark throughout the day. Radar shows a decaying line of
showers that now extends across central NH and this line will
continue to march east into ME over the next few hours. All rain
is expected along the coast and southern NH as this line moves
through but across the foothills where temperatures remain near
freezing some pockets of freezing rain will remain possible.
Across the far north and mountains, mostly snow is likely but
even in these regions some mixed precipitation cannot be ruled
out until colder air moves back in aloft. Slippery travel
conditions will be possible where the temperature is still
hovering near or even slightly above the freezing mark through
the evening hours. The other concern for this evening will
continue to be for areas of fog, which may become locally dense
at times with visibility dropping to around 1/4 mile at times.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
The closed low to our north will send a cold front southward
through northern New England tonight, which will bring an end to
the precipitation for areas south of the mountains. Across the
mountains and far north, increasing northwesterly winds behind
the front will allow for the development of upslope snow showers
through Friday morning. There could even be a localized heavier
snow squall late this evening and overnight tonight, especially
across northern NH and the Whites. Low temperatures tonight
will fall back to at or below freezing in most locations, except
along the immediate coast.

High pressure will begin to build into the area on Friday from
the west, but this will increase the PGF across the area. This
combined with steepening lapse rates and the presence of a LLJ
of around 40 kts will allow for gusty winds across the entire
area up to around 40 mph at times. Locally higher gusts are
likely immediately downslope of the mountains, where gusts may
locally approach 45-50 mph. Upslope snow showers will remain
possible across the far north through the middle of the day,
before winds begin to diminish towards evening as significantly
drier air moves into the area. Skies will be partly to mostly
sunny across the south but remain mainly cloudy in the
mountains. High temperatures will range from the 20s across the
north to the upper 30s along the coast and southern NH.

Winds will diminish on Friday night as mixing begins to decrease
and the PGF begins to slacken. Overnight low temperatures will
fall into the single digits across the north to the teens and
lower 20s elsewhere under mostly clear skies.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
The majority of the blocking across N Hemisphere at 500 MB is
mainly in the Arctic circle and in the sub-tropical regions,
leaving progressive and active flow in the mid-latitudes. This
will lead to a changeable period through next week, both in
terms of temps and precip chances.

Saturday will be mainly sunny but seasonably cool with highs a few
degrees below normal, in the mid-upper 20s N, to the upper 30s S.
Fast moving, and weak clipper-type low moves through Sat night, and
mostly focused on Sat evening.  Dry air mass will limit precip, but
brief surge of moisture ahead of it could produce some SHSN in the
mtns, mainly Sat evening.   Winds shift to NW behind the system, but
this could keep the upslope SHSN going into early Sun morning.  High
pressure builds in for Sunday providing a partly to mostly sunny
day, with highs a little warmer than Saturday, in the low 30s in the
mtns to around 40 in the S.

Very strong surge of warm air from the S moves in on the back side
of the high as deepening sfc low tracks NE across the great lakes.
Precip starts early Monday morning, likely as mixed precip inland,
but rain in srn NH and on the coast.   The warm air will move N thru
the morning with most everywhere but the mountaintops.   Could see an
inch or two of snow in the N before a changeover.  Forecasting to
reach 50-55 on the coastal plain, but strong S-SW flow could produce
enough mixing to allow a few spots near 60.  Could see wind gust of
25-30 mph, as well, highest near the coast. The mountains will see
highs of 45-50.  Precip, especially in the S and E, may be showery
through much of the day Monday, before a steadier rain moves in late
in the and into the evening. Once the cold front passes through, it
should clear out fairly quickly after midnight.

Sfc high builds in from the W Tue and cross the CWA Tue night. Highs
will be near normal again, in the 30s to around 40.  The next low
arrives Wed, and models are not settling onto any soln yet, so for
now, will go with the possibility of RA or SN, with SN more likely to
the N.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR/LIFR conditions will persist through this
evening, before a cold front crosses the area later tonight.
Across southern terminals, conditions will improve to MVFR/VFR
but across the north SHSN will result in continued lower
categories. VFR conditions expected tomorrow south of the
mountains but across mountain terminals such as KHIE, MVFR and
localized IFR conditions will remain possible through the
middle of the day within any SHSN. Widespread VFR conditions are
then expected on Friday night. Northwesterly winds may gust up
to 30-35 kts across all terminals late friday morning through
the afternoon.

Long Term... Mainly VFR Sat thru Sunday night, although SHSN
possible at KHIE Sat night. More widespread flight restrictions
expected Mon into Mon night with RA/FG and low cigs.

&&

.MARINE...
Short Term...Gale conditions expected tonight through Friday
afternoon as northwesterly winds gust up to 30-35 kts behind a
cold front. Winds will gradually decrease on Friday night but
seas will remain elevated at 3-6 feet outside of the bays.

Long Term..Brief period of SCA winds possible Sat night, and
then gales may be needed Monday..

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Gale Warning until 7 PM EST Friday for ANZ150>154.

&&

$$

UPDATE...Casey
NEAR/SHORT TERM...Cannon/Tubbs
LONG TERM...Cempa


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.