Area Forecast Discussion

FXUS61 KCAR 131108
Area Forecast Discussion
National Weather Service Caribou ME
608 AM EST Wed Dec 13 2017
Low pressure will move to the Gulf of Saint Lawrence today. A
ridge of higher pressure will build into the area this
afternoon, and will remain over the area until the next system
moves into Maine on Friday.
6:08 am update: a 982 mb low over Washington County will lift 
rapidly to the north and should be over the Gaspe Bay Peninsula 
by midday. Colder air is wrapping back around the low, and the 
rain has changed back to snow at Bangor as of 6 am, while mild 
air continues to surge up along the Maine/NB border with 
temperatures in the mid 30s with rain at Caribou. There is one 
last batch of precipitation across parts of the Downeast Region 
that will lift out within the next couple of hours, so the snow 
in Bangor is not expected to amount to more than a perhaps a few
tenths of an inch. As the low lifts north and colder air sweeps
in the wind will pick up and snow showers are expected across 
the north and mountains. Still a bit uncertain as to where the 
deformation zone sets up this afternoon, but it will be close to
the western Maine/Quebec border, and thus will allow the winter
storm warnings in the west to remain in place, but if it 
becomes more apparent that add'l significant snow will not fall 
the warnings could likely come down early. In any event, with 
the gusty wind, snow showers, and falling temperatures today it 
will be slick in spots with locally poor visibility at times. 
Previous discussion...
A deep area of low pressure along the Washington County coast 
early this morning will continue to deepen and lift north today.
The low is expected to be in western Labrador late tonight. As 
the low lifts north today a strong cold front will sweep across 
the area with the cold air filtering in rapidly from the 
southwest. There will still be a mild air mass aloft across far 
eastern Maine at 12Z with 925H temps well above freezing along 
and near the Maine/New Brunswick border all the way north to the
Saint John Valley. As of 3 am, it is raining at Caribou and the
temperature is up to 35F. Very little in the way of precipitation
falling across the Bangor Region and across Downeast area early
this morning. Temperatures range from around 50F along the 
Washington County coast to the low 30s in the Bangor area. Plan 
to cancel the winter weather advisories and warnings with the 
exception of zones 1, 3, 4, and 10. This is not to say that 
there will not be slick spots where there was already freezing 
rain and snow, but with little in the way of additional new snow
or ice this morning it does not warrant keeping the headlines 
going. Across the northeast zones, mostly rain early this 
morning that will transition to snow showers by late morning. 
The deformation zone associated with the low sets up mainly to 
the west of the area in Quebec, so not sure that there will even
be much in the way of steady snowfall falling this afternoon 
across the western zones, but some snow showers and gusty wind 
along with patchy blowing snow is likely across the north and 
mountains this afternoon.  It is possible that the warnings in 
the west will be able to be cancelled early, but will let the 
day shift get a look at just where the deformation zone sets up
during the day. A quick inch or two of snow may accumulate in 
some spots in the north and mountains this afternoon into this 
evening. As the low lifts north tonight it will remain cloudy 
across the north and mountains with a few snow showers and some 
blowing snow. Partly cloudy Downeast. Any standing water on 
untreated surfaces will freeze. Temperatures by morning will be 
in the single digits north to the teens along the coast, with
wind chills below zero.
The model guidance is in good agreement through the short term
period of the forecast. An upper level low over eastern Quebec 
will influence the weather for the area through much of the 
period. The low over eastern Quebec will slowly move NE towards 
the Maritimes Thursday. Another low pressure system will move 
into the north Atlantic near the NJ coast and will remain south 
of the Gulf of Maine waters exiting the region Thursday 
afternoon. Higher pressure will build into Southern Maine. By 
early Friday morning the low over Quebec will move into the 
Maritimes, and higher pressure will build into northern Maine. 
Another low and frontal system will move through the Great Lakes
region, reaching western Maine by the end of the period. 
Loaded a blend of the GFS/NAM/ECMWF to smooth out the minor
differences in the models. Loaded NAWAVE4 for seas in the
coastal waters. Loaded windgust by factor tool. For QPF used
The extended models are in good general agreement at the start
of the period. The extended models continue to indicate that 
they weather through the period will be influenced by an upper 
level low over Northern Quebec. It will spin up clipper system 
on a 12 to 18hr interval. No significant storms through the 
Loaded a blend to smooth out the differences in the models,
however the solution leans more towards the GFS solution. Used
NAWAVE4 for seas in the coastal waters. Used windgust by factor
NEAR TERM: IFR and at times LIFR at the northern terminals will 
improve to MVFR this evening, but occasional IFR or LIFR will remain 
possible at times tonight in passing  snow showers.  LIFR to IFR at 
KBGR and KBHB will improve to MVFR this morning and to VFR by late 
in the day. 
SHORT TERM: MVFR conditions across northern Maine with scattered
snowshowers. VFR conditions for Southeastern Maine. VFR
condition will extend into northern Maine Thursday afternoon as
higher pressure ridges in. VFR conditions will remain into
Friday evening, a frontal system moving into western Maine
Friday will displace the high pressure ridge. Ceilings will
begin falling in the afternoon Friday. MVFR conditions BHB and
BGR early evening, spreading to other sites by midnight. IFR
conditions at BHB and BGR early AM Saturday. Everywhere by
morning in snow and snowshowers. The frontal system and
associated low will clear the area Saturday evening, clearing
VFR conditions return to all sites by late Saturday afternoon.
VFR conditions will continue thru the day Sunday, MVFR in
snowshowers Sunday evening as the next system moves in.
NEAR TERM: A gale warning is in effect from late this afternoon 
through tonight as a strong area of low pressure lifts well to 
the north of the waters and a strong pressure gradient continues
across the area. 
SHORT TERM: A SCA for winds and seas transitioning to an SCA for
seas on Friday may be required.
ME...Winter Storm Warning until 7 PM EST this evening for MEZ001-
MARINE...Gale Warning from 4 PM this afternoon to 4 AM EST Thursday for 
Near Term...CB
Short Term...Norton
Long Term...Norton