Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 271640
Area Forecast Discussion
National Weather Service Caribou ME
1140 AM EST Mon Feb 27 2017
A cold front will cross the area today. Weak high pressure
builds tonight into Tuesday. A warm front will lift across the
.NEAR TERM /THROUGH TONIGHT/...
1140 am update...
Cdfnt clearly evident on vis imagery this mrng appchg St.
Lawrence with snow showers ahd of it, along with the ocnl
squall. Swrly flow gusting ahd of bndry acrs entire CWA and
current grids have this wl in hand. Updated sky cvr this mrng to
go mocldy acrs nrn zones for tda. Expect that snow along the
cdfnt wl impact nrn zones this aftn as bndry drops south tda. As
mentioned by prior shift, snow squall parameters look to be in
place hwvr with melting that occurred the past svrl days and
refreezing of snow on top do not foresee much problem with
blowing snow other than what can fall along bndry. No chgs
needed with this update.
A weakening clipper system is currently approaching and will
drag a cold front across the forecast area this afternoon. With
warm advection ahead of the cold front, highs today will climb
into the upper 30s north and mid 40s for Bangor and the Down
East region. This heating will generate steep low level lapse
rates and a lot of mixing to nearly H800. Strong winds aloft
means southwesterly gusts approaching 40 mph and perhaps more.
Do not foresee the need for a wind advisory at this point, but
will watch carefully. Precipitation with the front will be in
the form of mostly snow showers with cold air aloft overcoming
boundary layer warmth. Most of the snow showers will be in
northern zones by midday to early afternoon. The front will
continue to weaken as it moves south of Houlton and into the
Down East region. The snow squall parameter is quite high with
the front. As always, the snow showers will be low-topped and
difficult to see too far from the radar. CAPE values still reach
over 100 J/kg with the front in Aroostook County towards
midday. Fortunately, there is very little moisture with this
front, it will be fast-moving and there isn`t any loose snow to
blow around due to the recent thaw. Nonetheless, visibilities
could be temporarily reduced below a mile as the front comes
through. In terms of pops, have gone above most guidance. A
secondary trough enter the Saint John Valley later in the
afternoon and this is represents the tougher part of the
forecast. This trough could linger in northern zones...north of
Houlton...much of evening if not the whole night as it will be
parallel to the flow aloft. Meanwhile, high pressure builds over
the area tonight. Where it`s clear, light winds should produce
good radiational cooling and have reduced lows below guidance on
both the north and south sides of the stationary trough. Lows
will dip towards zero in the Saint John Valley.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
High pressure will cross the region Tuesday with generally
partly sunny skies. Low pressure tracking across the Great Lakes
region will then begin to draw a warm front north Tuesday
night. Rain/snow will expand across Downeast areas Tuesday night
with snow or a wintry mix across central and northern portions
of the forecast area. Any snow accumulations Tuesday night are
expected to be light. The low will track northeast from the
Great Lakes Wednesday into Wednesday night though the exact
track of the low is still uncertain. The warm front will move
north across the region Wednesday with the snow or wintry mix
transitioning to rain, from south to north, across the forecast
area. Whether the the low tracks northwest of the region or
across the region Wednesday night is still uncertain. A track to
the northwest would keep precipitation mostly rain until a cold
front late could allow a transition back to snow showers across
the north and mountains. A more southern track across the
forecast area could draw colder air across northern areas more
rapidly with rain transitioning to snow with a better chance of
accumulation across the north and mountains. Temperatures will
be at above normal levels Tuesday/Wednesday.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A cold front will cross the region either Wednesday night or
early Thursday dependent on the track of the low. Expect a
chance of snow showers across the north and mountains Thursday,
with decreasing clouds Downeast. Low pressure should track
south of the region Friday with generally partly sunny skies
across the forecast area. High pressure should then build across
the region later Saturday into Sunday with partly cloudy/mostly
clear skies along with colder temperatures. Temperatures will
be at above normal levels Thursday. Below normal level
temperatures are expected Friday/Saturday, with near normal
level temperatures Sunday.
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions are expected except in scattered
afternoon and evening snow showers. These showers will be mostly
north of HUL. There is a slight chance of a more stationary
line of snow showers lingering around PQI and HUL through the
evening. Winds are the other issue today with gusts of 30 to 35
kts from the southwest.
SHORT TERM: VFR conditions are expected Tuesday. MVFR/IFR
conditions should then develop Tuesday night, with similar
conditions then persisting Wednesday into Wednesday night.
Occasional MVFR conditions are possible Thursday, particularly
across the north and mountains. Generally expect VFR conditions
across the region Thursday night into Friday.
NEAR TERM: Will not change the SCA at this time. Winds will
increase this morning ahead of a cold front, but decrease
sharply this evening with the weakening front.
SHORT TERM: Conditions are expected to be below small craft
advisory levels Tuesday/Tuesday night. Small craft advisory
conditions are then expected Wednesday into Wednesday night.
Visibilities will be reduced in rain later Tuesday night into
Rivers are starting to crest with the only current concern being
the Kenduskeag Stream near Bangor. Will monitor this situation
and cancel the Flood Watch.
MARINE...Small Craft Advisory until 7 PM EST this evening for