Scientific Forecaster Discussion
fxus61 kgyx 182326
Area forecast discussion
National Weather Service Gray ME
626 PM EST Mon Nov 18 2019
low pressure off the mid Atlantic coast will move northward
into the Maritimes tonight. A light wintry mix is expected to
change to rain over southern and coastal sections by evening.
In the mountains and foothills, freezing or frozen precipitation
is expected to linger through Tuesday morning. The next weather
system looks to move eastward across the forecast area late in
the week, possibly followed by another low pressure system later
in the weekend.
Near term /until 6 am Tuesday morning/...
have updated the forecast per latest radar imagery and surface
observations. Rain continues to fall over southern Maine and
southern New Hampshire with pockets of sleet and freezing rain
over central areas where winter weather advisories remain in
effect. Temperatures will likely hover in the lower to mid 30s
throughout the night with little change.
at 19z a 995 millibar low was situated southeast of
the benchmark. Steadier precipitation from this system
continues to spread westward into the area. While we're warming
aloft the cold air has been slow to erode away from the
immediate coast. With precipitation onset there should be enough
cooling of the column for at least a brief transition to light
freezing or frozen precipitation through early evening over may
areas immediately inland from the coast. For that reason...i've
extended portions of the advisory until 9 PM. Across the
mountains and foothills we should remain cold enough for light
freezing and frozen precipitation overnight. The steadier
precipitation should taper for a time overnight as the first
impulse and surface low begin to pull away. However...a second
impulse will be approaching from our southwest towards dawn
along with a second batch of precipitation. Temperatures tonight
will range from near 30 in the mountains to lower and mid 30s
Short term /6 am Tuesday morning through Tuesday night/...
another quick round of steadier precipitation on Tuesday morning
as the second impulse crosses the area. Across the mountains we
should mixed precipitation changing to snow. Elsewhere...mainly
rain should fall possibly mixed with a bit of sleet. Highs
should be mainly in the 30s with a few 40 degree readings over
southeast New Hampshire and the southwest Maine coast. Partial
clearing outside the mountains Tuesday night as we're briefly
between disturbances. Clouds from the next ocean low should
arrive across the area by Wednesday morning.
Long term /Wednesday through Monday/...
an active pattern will continue through the next week. Trough
over the Great Lakes will move through our area in the start of
the week before making way for a ridge mid week. The next
disturbance drops out of the north for the end of the week. Lots
of variability for the end of the week as a closed low and
blocking pattern out of the Pacific makes it tough for much to
Wednesday another coastal low passes well off shore. While the main
precipitation will be further east than our area, there is some
potential for an inverted trough to bring some light
precipitation into the ME/New Hampshire border and have increased pop
slightly to chance along this region. Overcast skies will also
be present throughout the day with just a chance for clearing
overnight on Thursday as the low moves further east.
High pressure builds in from the west for Thursday. As
temperatures aloft rise through the end of the week surface
temperatures will return to near normal values with highs in the
mid 40s. In the south have increased temperatures slightly as
the clearing skies should help out a bit.
Overnight Thursday into Friday flow will turn southerly as warm
advection begins ahead of the next system. Increasing clouds may
even lead to some light drizzle by early morning as lower levels
The warm advection continues on Friday as temperatures soar to over
50 degrees across southern New Hampshire. Low pressure will develop over the
Great Lakes and track north of the region. On Friday as the warm
front lifts northwards we will see scattered showers with rain south
and snow aloft. We remain in the warm sector until late on Friday
when the cold front will move through with a burst of precipitation
and a shift to nwly cold advection. With a potentially strong
frontal passage will have to be alert for the potential for snow
squalls in the mountains.
The progressive pattern looks to continue into the weekend with
another low passage on Sunday.
Aviation /23z Monday through Saturday/...
short term /through Tuesday night/...MVFR with areas of IFR in
rain and ice pellets with a mix of -fzra/ip/sn for the mountains and
foothills through Tuesday. Lingering MVFR cigs Tuesday night in
mtn sections and becoming VFR elsewhere.
Long term...generally VFR conditions will prevail through the
middle of the week, on Wednesday low pressure will pass
offshore with a chance for an inverted trough to bring some
scattered rain/snow showers into the ME/New Hampshire border and this could
result in a brief period of IFR in the afternoon. High pressure
builds in for Thursday and Thursday night. By Friday warm air
advection will take hold and we'll see ceilings decreasing to
MVFR as another system approaches for Friday. Expect rain and
snow on Friday with IFR as a front moves through late Friday
short term.../through Tuesday night/...strong winds with gales
open waters/Small Craft Advisory for bays will gradually subside overnight. It's
likely we'll see a lingering Small Craft Advisory for seas on Tuesday into
Tuesday night outside the bays.
Long term...another low will pass east of the waters on
Wednesday with just a few lingering showers over the waters.
High pressure will build across the region late Thursday before
the next low moves through on Friday. Cold front will cross the
waters late Friday night with gales possible under cold
ME...Winter Weather Advisory until 9 PM EST this evening for
Winter Weather Advisory until 11 am EST Tuesday for mez007>009-
New Hampshire...Winter Weather Advisory until 9 PM EST this evening for nhz006-
Winter Weather Advisory until 11 am EST Tuesday for nhz001>005-
Marine...Small Craft Advisory until 4 am EST Tuesday for anz151-153.
Gale Warning until 4 am EST Tuesday for anz150-152-154.