NWS Caribou, Maine Area Forecast Discussion

FXUS61 KCAR 241644

Area Forecast Discussion
National Weather Service Caribou ME
1244 PM EDT Sun Jun 24 2018

A cold front will slowly move southward across the area today.
Low pressure will develop along the front in the Gulf of Maine
tonight and move east into the Canadian Maritimes Monday. High
pressure will build in from the west Tuesday and slide to our
south on Wednesday.

1245 AM Update: Lowered pops today as there`s not much precip
along the cold front until late day when the low
organizes...other than a few sprinkles falling out of higher
clouds. Precip with the low is currently in southern Ontario,
but is moving quickly into Quebec and upstate NY. Pops will
increase rapidly late this afternoon into the evening as the low
arrives, but the max QPF and Pops were shifted further south
and reduced. The rain moves out early Monday and decreased
clouds for Monday in many northern locations. It will be a cool
day with highs in the low to mid 60s. Showers will still be an
issue with the upper trough passage and will have to consider
adding isolated thunderstorms with the cold air aloft along the
far western international border.

Orgnl Disc: We bumped up PoPs across spcly Nrn ptns of the FA
going into the morn hrs to account for sct shwrs movg ewrd from
Cntrl QB. We also kept a mention of patchy fog for the Srn hlf
of the FA for a few more hrs which experienced most rain from
the first weak low, but sfc obs show little if any sign of fog,
so we may drop mention of this on our next update by 6 am.

Otherwise, after a break from steady rn tdy which may show brief
pds of sunshine in cld cvr breaks, all models agree that a new
wv of sfc low pres will take shape ovr the Gulf of ME beginning
by erly eve as a sig s/wv trof alf digs SE from Hudson Bay Can.
Rnfl, which will initially form in a low to mid layer
frontogenic band ahead of the s/wv ovr Nrn and Cntrl ptns of the
FA this eve, will become most organized ovr Cntrl and Downeast
areas late tngt as mid lvl vort advcn from the s/wv trof catches
up with the developing sfc wv. All Models show a sharp cut-off
of rnfl totals across the far NNW, where llvl dry air from Cntrl
QB may entrain into, so confidence of rn totals ovr this ptn and
adjacent N Cntrl and far NE ptns of the FA are not as high as
for the rest of the FA. Suffice it to say, most of the FA will
receive another half to three quarters of an inch of rnfl
ovrngt prior to steady rnfl tapering to sct shwrs by mid Mon
morn, with amounts steadily decreasing from a half inch N and W
of a Presque Isle-Ashland line to arnd a tenth to two tenths in
the St John vly area from Escourt Stn to Frenchville area.

Temps will be cooler tdy due to cld cvr and isold to sct shwrs
and then cooler tngt due to both steady rnfl and weak to mdt
llvl cold advcn behind the exiting Gulf of ME sfc low.

Low pressure sliding to our south will be tracking across western
Nova Scotia Tuesday morning. Rain, mainly over Downeast and east
central areas, will taper off as the low tracks away to the east.
This will leave the area mostly cloudy under the upper level trough.
Both the NAM and the GFS are indicating that some showers may form
in the back side of the trough across western and northwestern areas
during the afternoon. This moisture should dissipate Monday night as
the upper trough shifts east and high pressure begins to build in
from the west. High pressure will bring a sunny and seasonable day
on Tuesday followed by a clear night Tuesday night as the high
slides to our south.

Our focus on Wednesday will be on a storm system approaching from
the Great Lakes. Wednesday will begin sunny then clouds will
increase late in the day. Showers will spread in from the west
Wednesday evening as the low tracks east of the Great Lakes. This
low is expected to track up to our northwest pulling moisture and a
humid south wind with widespread showers Wednesday night into
Thursday. Some isolated thunderstorms from elevated instability
can`t be ruled out. Showers will taper off late Thursday. The sky
will likely remain cloudy except for some possible brightening late
in the day Downeast. The sky will then partially clear Thursday
night followed by partial sunshine on Friday as high pressure, both
surface and aloft, builds to our south. Long range forecast guidance
including both the GFS and ECMWF are showing the potential for a
period of very warm weather beginning late in the week and lasting
through the weekend and into the first week of July. We will be on
the northern edge of the ridge at the end of this month into the
first few days of July. Upper level disturbances and convective
complexes along the northern edge of the ridge may complicate how
far north the hot air reaches, but some very warm air is likely to
reach the area at least for part of the time. A more prolonged heat
spell is likely southwest or our area.

NEAR TERM: Nrn TAF sites will remain msly VFR tdy while Downeast
sites transition from MVFR clgs to VFR by late morn. All sites
will then lower to MVFR clgs/vsbys tngt in rn with intervals of
IFR clgs/vsbys with more mdt rnfl rates late tngt from KHUL

SHORT TERM: MVFR conditions Monday morning will improve to VFR
by midday. VFR conditions are likely Monday night through
Wednesday. Conditions will then drop from VFR to MVFR then IFR
Wednesday evening as low clouds and showers move in. IFR
conditions will likely last through midday Thursday becoming
improving to MVFR late in the day.

NEAR TERM: No hdlns xpctd for the near term attm, with winds
increasing from the NE late tngt with gusts up to 20 kt by erly
Mon morn behind a developing sfc low as it moves E into the Can
Maritimes. Cannot rule out left over patchy fog very erly this
morn, and again later tngt with the arrival of mdt rnfl rates
ovr the waters. Kept close to WW3 guidance for fcst wv hts this
update with primary wv pds xpctd to be between 6 and 8 sec.

SHORT TERM: A few wind gusts may reach 25 kt in northeast winds
Monday morning as low pressure exits east of the waters.
Otherwise, winds and seas are expected to be below SCA through
Monday night. West winds may approach 25 kt in Gusts Tuesday
into Tuesday night. A SCA will then be likely late Wednesday
night through Thursday as low pressure lifts west of the waters.


Near Term...VJN
Short Term...Bloomer
Long Term...Bloomer

NWS CAR Office Area Forecast Discussion