Scientific Forecaster Discussion
fxus61 kgyx 240351 aac
Area forecast discussion...updated
National Weather Service Gray ME
1151 PM EDT Wed Oct 23 2019
low pressure exits through the Canadian Maritimes tonight with
drier weather behind it. A ridge of high pressure follows for
Thursday. A cold front will cross the area Friday with a few
clouds and scattered showers. High pressure and drier air
follows for Saturday. Another round of showers is possible late
Sunday into Sunday night as weak low pressure moves though New
Near term /until 6 am Thursday morning/...
update...minor changes to reflect latest observational trends.
Previous discussion...as the system continues to pull east into
the Canadian Maritimes tonight, drier air will continue to
filter into our region on westerly breezes. Some cloudiness
associated with the upper level trough to our west and moisture
coming in off Lake Ontario will bring a few clouds to the region
tonight. Most cloud cover will be over upslope regions of the
Due to the westerly gradient overnight, temperatures will remain
above freezing with mid 30s in the north to the lower 40s in the
Short term /6 am Thursday morning through Thursday night/...
some upslope clouds remain in the mountains Thursday. Otherwise,
mainly sunny and dry conditions will continue over Maine and New
Hampshire. 800 mb temperatures between +4 and +7c will allow for
readings in the 60s in most areas outside the mountains.
Clouds will gradually increase Thursday night as a slow moving
cold front crosses into the region. This front will be
relatively moisture starved with any widely scattered showers
confined to far northern areas.
Long term /Friday through Wednesday/...
the seasonal migration of the jet stream continues with a
fairly high amplitude and active pattern continuing across the
northern part of North America through the start of next week.
At the end of the week we have a trough dropping down over The
Rockies with a ridge built over the West Coast. This ridge will
continue to amplify through the start of next week as a trough with
several waves digs in the central part of noam. By the end of the
weekend the spread amongst the various guidance is very large due to
the variability in the strength of the West Coast ridge and
corresponding trough through the central part of the country.
Friday night: a weak short wave will move through the region
touching off some scattered showers. As temperatures aloft cool
down this will result in a change over to snow showers in the
mountains with minor accumulation. Winds will come around to northwest
with some additional snow showers possible on the leading edge
of the cold air advection on Saturday morning. While it's not quite moist
enough for full snow squalls some more convective showers are
likely and have increased pops through the moutnains on Saturday
Saturday and Saturday night will see high pressure build into
the region. With the cold air departing to the northeast during
the day Saturday, and clouds encroaching Saturday night low
temperatures will stay fairly moderate with temps hovering just
above freezing south and just below freezing north.
Our next system begins to approach the region on Sunday. Low
pressure will move up the Ohio River valley and cross southern
Ontario through the day on Sunday. Ahead of this system expect
rain to move into southwestern New Hampshire early Sunday
morning and spread across the region through the day. As the
trailing cold front moves off shore south of Long Island expect
secondary low pressure to spin up and move up the Maine coast
through the day on Sunday. With southeasterly flow ahead of the
system and a retreating high to the NE expect a coastal front
to set up. This front will help to focus rainfall along the
The low will shift east of the area through the Gulf of Maine on
Sunday night with flow becoming nwly and scattered showers remaining
in the mountains.
Another system will move in Tuesday or Wednesday, however
uncertainty in the overall pattern has lead to a wide range of
timing possibilities. For now will stick with a consensus of
models, with a chance of rain throughout the period. Will likely
take until the start of the weekend to be able to narrow down
Aviation /04z Thursday through Monday/...
short term...widespread VFR tonight thru Thu. Much drier air
moved into the area late this afternoon which should preclude
widespread fog tonight...but recent rainfall does give ME a
little pause. Too much uncertainty to include in tafs right now
Long term...a weak front may bring a few scattered showers and MVFR to
the mountains for Friday night into Saturday. High pressure builds
in with VFR for Sunday. Our next major low pressure system will move
into the region Sunday morning and continue through Sunday
night with widespread IFR in rain.
will continue scas for the outer waters, mainly due to high seas
tonight. Scas all areas on Thursday.
Long term...next major system will move in on Saturday night
into Sunday with increasing southerly flow across the waters.
Small Craft Advisory will likely be needed.
Marine...Small Craft Advisory until 6 PM EDT Thursday for anz150-152-
Small Craft Advisory from 8 am to 6 PM EDT Thursday for anz151.