Scientific Forecaster Discussion
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Area forecast discussion...updated
National Weather Service Gray ME
912 PM EST Wed Nov 13 2019
high pressure will crest over New England tonight with dry
conditions and very cold air over the region. Conditions remain
generally dry through Thursday with only light snow showers
possible. While Friday looks warmer, it is short-lived with an
outbreak of Arctic- sourced air behind a cold front late in the
day. Below normal temperatures stick around through the weekend
with a warm trend and return of active weather next week.
Near term /until 6 am Thursday morning/...
910 PM update...
quiet night with intense cold ongoing. Overnight lows look good
with 0 to -5 f likely over the mountains and 5 to 10 degrees f
across the south. No major changes to the forecast at this time.
605 PM update...
temperatures are dropping this evening and will make a run at
low temperature records (see below) overnight. Sky cover and
hourly trends were adjusted for latest data. Otherwise forecast
is on track.
record cold temperatures expected tonight...
First, unofficially, it looks like we may have set mini-Max
records at pwm, con, and Aug...but we will wait and see until
later this afternoon for official confirmation. See the climate
section below for the records for today and tonight.
Surface high pressure will settle overhead tonight and set the
stage for a very cold night for mid-November. Temperatures this
afternoon topped out a degree or two below what we expected, so
made some slight adjustments to overnight temperatures from the
previous forecast. Overall not much change, meaning that lows
will fall into the negative single digits in the mountains and
into the positive single digits pretty much everywhere else.
Locations right along the coast may just barely remain in the
teens. With mostly clear skies this evening, temperatures will
begin to fall rapidly after sunset; clouds moving in after
midnight may prevent temperatures from falling any further, but
the damage will likely be done, so to speak. The good news is
that with the high pressure overhead, winds will calm down and
keep apparent temperatures above those that we saw this morning.
As far as sensible weather, nothing is expected overnight.
Short term /6 am Thursday morning through Thursday night/...
scattered snow showers are possible on Thursday, primarily in
the mountains as an upper level trough approaches. In addition,
southwesterly winds may bring some clouds and perhaps a flurry
or a shower to the midcoast region of Maine as limited moisture
arrives off the Gulf of Maine. Any accumulation in either case
should be very light.
Long term /Friday through Wednesday/...
model long range trends are for a more zonal flow at 500 mb
with the cold air retreating at 850 mb. This, should lead to
trend back to normal temps next week after another shot of cold
air this weekend. There's even potential for above normal temps,
but troughing developing to our west may lead to a more active
with more clouds and precip keeping the temps down.
On Friday cold front will approach from the northwest and temps should
push up into the 40s outside the mtns, with 30s in the mtns,
the front will cross the County Warning Area during the afternoon, and dry air
mass should limit coverage of any showers associated with the
front, but some signals are there for snow squall potential,
especially in the nrn zones. Once the front passes, northwest winds
will pick up again and the cold air will stream in Friday night
and Sat. It doesn't look quite as cold ad the cold air surge,
but lows Fri night will be in the single digits north to the teens
in the south, with highs on Saturday 20-25 in the mtns to the
low 30s in the south. Will see the northwest winds persist into
Saturday morning, but will diminish during the afternoon. The
sfc high moves overhead Sat night so, a good rad cooling night
will push the mtn valleys close to zero again, while the
southern areas will range from around ten to the upper teens.
Models are more on the same Page today with keeping low
pressure offshore well to our S and E, and will likely only
produce some clouds for coastal areas. Highs on Monday will
reach into the mid 30s north to the low 40s S. Models still showing
uncertainty as to the nature of the next system which will
produce a deeping 500 mb closed low to our S and E, with
associated sfc cyclone, offshore. Questions as to how much
precip spreads back to the north and west and temps make this a low
confidence forecast, but it is something to watch.
Aviation /02z Thursday through Monday/...
short term...VFR conditions at all terminals through the short
term, although rkd and hie could see brief MVFR/conditions in
-shsn on Thursday into Thursday night.
Long term...mainly VFR expected Fri night thru Monday. Could se
some temps flight restrictions in shsn Fri afternoon and night
short term...winds should begin to diminish this evening but
scas remain in effect through 8pm. Winds and seas likely to
remain below Small Craft Advisory criteria through Thursday night.
Long term...scas will likely be needed Fri night into Saturday
in northwest flow behind a cold front, and there's the possibility of
a period of gales.
records for Portland
November 14, record low: 12f set in 1986
Record for Concord
November 14, record low: 7f set in 1986
Record for Augusta
November 14, record low: 13f set in 1986