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Area Forecast Discussion (AFD)

Issued by Caribou, ME (CAR)

FXUS61 KCAR 181008

Area Forecast Discussion
National Weather Service Caribou ME
508 AM EST Mon Feb 18 2019

Low pressure will track south of Cape Cod eastward into the open
Atlantic Ocean today. High pressure will build across the 
region tonight into Wednesday.

The steep and shallow radiation inversion that produced lows
approaching minus 20F in northern Aroostook County will be
eliminated with morning heating. Highs today will reach the
teens in northern zones while upper 20s to around 30F are
anticipated for Bangor and the coast.  With the low pressure 
track so far south, the only effects for the forecast area will 
be mid and high clouds and some light snow when the upper trough
crosses this afternoon. The low will be deepening as it moves 
into the Atlantic and there will be some moisture wrapping back 
towards the low amplitude upper trough. Very dry low levels will
impede precipitation reaching the surface initially, but by
early afternoon, Bangor and MDI should see a couple hours of
light snow. Amounts will be less than an inch.  As the upper 
trough crosses, the moisture will quickly push southward out of 
the forecast area and another round of cold air advection will 
be the story tonight. Steady north winds resulting from a 
tightening pressure gradient will prevent another radiation 
inversion, but the combination of these winds and cold air 
advection means Wind Chill Advisory criteria will be met after 
midnight into early Tuesday morning. 

A Wind Chill Advisory is in effect across northern areas 
Tuesday morning. High pressure will build across the region 
later Tuesday into Wednesday. Expect partly sunny skies north, 
mostly sunny Downeast, Tuesday. Mostly clear skies are expected 
Tuesday night, with mostly/partly sunny skies Wednesday. Low 
pressure will approach from the west Wednesday night. Clouds 
will increase early Wednesday night, with snow developing across
the region later Wednesday night. Temperatures will be at below
normal levels Tuesday/Wednesday.

The low will move east across the region Thursday with
accumulating snow, though amounts are still uncertain. Generally
expect precipitation to remain in the form of snow Thursday,
though the snow could mix with rain along the Downeast coast
during the afternoon. The low exits across the Maritimes 
Thursday night with snow tapering to snow showers. High pressure
should cross the region Friday with generally partly cloudy 
skies north, mostly sunny Downeast. Clouds should increase
Saturday. Low pressure will track from the Great Lakes toward 
northern Maine Sunday. The low will bring another chance of snow
to the region, with snow again possibly mixing with rain along
the Downeast coast during the afternoon. Temperatures are 
expected to be at near normal, to slightly below normal, levels
Thursday through Sunday. 

NEAR TERM: Expect primarily VFR conditions through tonight 
except some light snow towards BGR and BHB that will produce 
MVFR tempo IFR vis...mostly early this afternoon. 

SHORT TERM: VFR conditions are expected Tuesday into Wednesday.
Conditions will lower to MVFR/IFR levels Wednesday night.
IFR/LIFR conditions are expected Thursday. Conditions will then
improve to VFR/MVFR levels later Thursday night. Occasional MVFR
conditions are possible across the north and mountains Friday, 
with VFR conditions Downeast. 

NEAR TERM: Winds will increase tonight along with much colder
temperatures moving over the waters. This means a Small Craft
Advisory will be needed tonight and moderate freezing spray will
develop after midnight.

SHORT TERM: A Small Craft Advisory is in effect through Tuesday
evening. Generally expect small craft advisory conditions 
Tuesday night into Wednesday night, though conditions could 
briefly fall below small craft advisory levels later Wednesday.
A Freezing Spray Advisory for moderate freezing spray is in 
effect through Tuesday morning. Light freezing spray is expected
later Tuesday. Visibilities will be reduced in developing snow 
Wednesday night.

ME...Wind Chill Advisory from 2 AM to 10 AM EST Tuesday for 
MARINE...Small Craft Advisory from 9 PM this evening to 7 PM EST 
     Tuesday for ANZ050>052.
     Freezing Spray Advisory from midnight tonight to 10 AM EST 
     Tuesday for ANZ050>052.

Near Term...MCW
Short Term...Norcross
Long Term...Norcross