Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCAR 041609
Area Forecast Discussion
National Weather Service Caribou ME
1109 AM EST Sun Dec 4 2016
High pressure will build across the region today and tonight. A
weak trough of low pressure will cross the region Monday into
Monday night, then high pressure resumes for Tuesday.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --11:00 AM update...Added some isolated snow showers to east central
areas through midday with some very light streamers of flurries
showing up on radar. Cooled temps a couple degrees into early
afternoon Downeast. Otherwise, no major changes this hour.
Previous discussion...An upper shortwave will push east of the
state early this morning, which will bring any lingering snow
showers or flurries to an end shortly after daybreak. High
pressure will follow, building into New England today and cresting
over the region tonight. This will be a much cooler and drier
airmass, which will serve to gradually erode cloud cover from
south to north through the day today. Temperatures will remain on
the cool side, topping out in the mid 20s in the north and the mid
30s south. Tonight will be the coldest we`ve seen so far this
season. Given mostly clear skies, light winds, and fresh snowpack,
lows in the single digits seem reasonable in the north. Further
south, temperatures will bottom out in the teens, with the
immediate coast staying around 20.
-- End Changed Discussion --
.SHORT TERM /MONDAY THROUGH TUESDAY/...
Below average temperatures and no significant weather systems
Monday into Tuesday. A mid/upper level ridge across the area
Monday morning is replaced by a trough by late day, which is
followed by a building ridge Tuesday. A weak surface trough
approaches from the southwest Mon morning may hold together enough
to produce a few snow showers, mainly across the Down East region
and perhaps across the far western zones. There is some hint that
a vEry weak coastal low may try to form Monday afternoon, which
might produce a period of light snow in parts of coastal Hancock
County with accumulations of up to an inch. It will clear out
behind this very weak system Mon night with lows mostly in the 10
to 15 degree range in the north and 20 to 25 Down East. Tuesday
will be partly to mostly sunny, but cold with highs from the low
20s across the Crown of Maine to near 30 degrees Down East.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
High pressure crests over the region Tue evening and shifts east
late Tue night. The night will likely start clear with an
increase in clouds after midnight. An area of low pressure is
expected to pass off the Middle Atlantic Coast Wed with a
weakening surface trough to approach from the west. Wed will be
mostly cloudy with flurries and perhaps a little bit of light snow
across mainly the western half of the CWA. Attention turns to the
next shortwave that rotates around a large upper low moving out of
Ontario and into western Quebec. The model spread is huge looking
at both the GFS and ECWMF ensembles. From the 12z ECMWF ensembles
about 2/3s of them have a weaker and more suppressed low which
would produce a light sub advisory snowfall. About 1/3 of the
members have a much stronger low and would produce a heavy wet
snow across the northern half of the CWA. The GFS ensembles also
have a lot of spread in both the depth and location of the low.
fairly high confidence that there will be some precipitation
developing Thursday and continuing Thu night, but forecaster
confidence on the specific details remains low. A shot of cold air
with some snow showers and flurries across the Crown of Maine in
the wake of the low for Fri into Sat.
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: While BGR and BHB will see prevailing VFR conditions
through the next 24 hours, MVFR ceilings will linger into early
this afternoon at the northern terminals. The northern sites
should see ceilings rise above 3000 ft by 18z with the clouds
thinning through the evening hours.
SHORT TERM: VFR Mon and Tue, with the possible exception of some
MVFR ceilings Mon PM at KBHB in light snow. Predominately MVFR Wed
with IFR/LIFR Thu and Thu night in snow north and rain or snow
NEAR TERM: The Small Craft Advisory remains in effect for the outer
waters through this afternoon. North winds of 15 to 20 kt with gusts
to around 25 kt will continue much of the day. The inner waters
could see a few gusts up to 25 kt but this should be the exception
rather than the rule, so have opted to not expand the SCA at this
time. Winds will subside later today and overnight as high pressure
builds into the region. The offshore flow will keep seas below 5 ft
through the period.
SHORT TERM: The next weather system will likely bring small craft
advisory conditons Thu afternoon and Thu night with a gale
possible. As low pressure pulls away strong sca conditions or low
end gales are expected Fri as cold air sweeps over the waters.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ050-