South Berwick, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

491
FXUS61 KGYX 231535
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1035 AM EST Mon Dec 23 2024

.SYNOPSIS...
Dry conditions and slightly warmer temperatures are expected
today before a clipper system brings light snowfall tonight into
the first half of Tuesday. High pressure will then build over
the region Wednesday through the end of the week with a gradual
moderating trend and mainly dry conditions.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...
A quick update this morning to account for clouds crossing the
region and current trend in temperatures and dew points. Will
continue to monitor 12Z model runs for possible expansion of the
Winter Weather Advisories into portions of northern Maine as
well as the Penobscot River Valley.

Prev Disc...
630 AM Update... Minor changes to reflect latest observational
trends.

Previously...
Nighttime microphysics early this Monday morning shows mainly
clear skies over the region. Current temperatures range from the
teens below zero across the northern valleys to the single
digits either side of zero elsewhere. There remains some light
flow at times but overall most locations have decoupled at this
point, which will continue to allow for strong radiational
cooling through sunrise. It will therefore continue to be a very
cold but dry morning and you will want to bundle up if heading
outside.

Surface high pressure will remain over thee region today before
an approaching frontal boundary pushes it offshore this evening.
Initially skies will be clear across the region but there will
be a gradual increase in middle to upper level clouds from west
to east throughout the day, as seen on the latest HREF and
upstream satellite imagery. H8 temperatures will be about 5C
warmer than yesterday and this will allow for warmer high
temperatures, which will range from the teens across the north
to the lower and middle 20s south. One noticeable difference
today will be much less wind than previous days and therefore
windchills won`t be much of a factor.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
A clipper system will pass over eastern NY and southern New
England tonight into Tuesday with overrunning precipitation from
WAA aloft spreading over the region from the sfc warm front.
Latest hi-res guidance indicates that light snow will begin over
the CT River Valley between 9-11 pm before spreading
southeastward over the rest of the area around or shortly after
midnight. Total QPF currently ranges from a few hundredths of an
inch across southern NH to up to around 1/4" further to the
north. While these amounts are rather low, SLRs will be rather high
at between roughly 13-18:1, and therefore this will be a
"fluffy" snow. Initially most guidance has decent saturation
within the -12C to -18C DGZ but then most models have a dry
slot pivoting through southern NH and into York and perhaps
Cumberland counties in ME during the overnight hours and into
Tuesday morning. As a result, snowfall amounts are lowest in
these regions with generally between 1-2" expected. Further to
the north and east 2-4" are currently forecast with locally
higher amounts possible. Based on collaboration with WFO
Burlington, went ahead and issued a Winter Weather Advisory for
Coos and Northern Grafton counties in NH, which is where
confidence is greatest for widespread 4+" amounts. Depending on
trends today this may need to be expanded some but currently
confidence is too low.

Snow will quickly end from northwest to southeast on Tuesday
with the mountains seeing their last flakes during the morning
before stopping by around lunchtime over coastal and southern
locations. Lows tonight will mostly be into the teens and highs
on Tuesday will be into the 20s and lower 30s from north to
south.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Long Term Update... Little change to the previous forecast.
Mainly dry conditions and near avg temperatures are expected for
the extended portion of the fcst.

Previously...
Overview...

An expansive ridge builds across eastern North American through
the middle and later portions of the week, and persists into
next weekend. High pressure at the surface keeps primarily fair
conditions ongoing into next weekend.

Details...

High pressure steadily builds in through Christmas Day, with
highs warming into the mid 20s to low 30s across most of the
area under mainly sunny skies. A few more clouds are likely
through the MidCoast and parts of central Maine as an inverted
trough lingers across DownEast Maine and New Brunswick.

Through the remainder of the week, the ridge builds across
eastern North America, bringing a very warm pattern for much of
the country and Canada. However, high pressure at the surface
across and just north of New England looks to thwart the bulk of
this warmth, resulting in a fairly consistent stretch of highs
in the mid to upper 30s each day, and lows in the teens and 20s
each night. Overall, these highs are pretty close to average
along the coast and southern areas, but about 5-10 degrees above
normal across the interior and northern areas. Over the past
few days the trend amongst the models has been for the this
warm up to be subdued as we get closer in time. This trend
continues with today`s forecast, with forecast highs trending
downward by another degree or two through the end of the week.

More uncertainty remains on whether or not warmer air
eventually moves in after next weekend. Following a mainly quiet
stretch from Christmas Day through next weekend, signals are
pointing towards a stormier pattern returning early next week.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
Short Term...VFR conditions will prevail through 00Z Tuesday
with light and variable winds. -SN overspreads the region
tonight before ending from northwest to southeast on Tuesday.
This will likely bring MVFR to perhaps localized IFR conditions
to most terminals. Conditions will then improve later Tuesday
back to VFR with winds mostly below 15 kts. No LLWS is
anticipated.

Long Term...VFR prevail from Wednesday through the weekend.

&&

.MARINE...
Short Term...A brief period of SCA level southeasterly winds and
seas is possible over the outer waters tonight into early
Tuesday as a weak system crosses. Otherwise, wind and seas will
remain below SCA levels.

Long Term...Fair conditions then prevail from Tuesday night through
the weekend as high pressure settles across the waters.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...Winter Weather Advisory from 7 PM this evening to 1 PM EST
     Tuesday for NHZ001>003.
MARINE...None.

&&

$$

NEAR/SHORT TERM...Cannon
LONG TERM...Clair/Ekster