FXUS61 KCAR 181057

Area Forecast Discussion
National Weather Service Caribou ME
557 AM EST Fri Jan 18 2019

Weak low pressure moves across the region today, followed by an
arctic cold front tonight and arctic high pressure on Saturday.
A Noreaster is expected to approach from the southwest Sunday,
move through the Gulf of Maine Sunday evening, then move across
the Maritimes on Monday.


555 AM Update...
Latest radar imagery is showing some light returns developing
across northern and downeast Maine at this hour. Bangor was
reporting a few flurries last hour, otherwise not much of this
appears to be making to to the ground attm. That will change as
we go a little further into the morning hours and still
expecting some light snow to begin to develop by mid morning
most areas. Just some minor tweaks to current temps and dew
points otherwise no other changes.

previous discussion
Clouds continue to increase this morning as high pressure
moves east across the Canadian Maritimes. Moisture will increase
as south wind develops on the backside of the departing high
with some light overunning snow expected to develop across the
region today. QPF is light with this event so we are only
expecting snow amounts to range from around an inch or two
across most of the region. Today will be several degrees warmer
than yesterday with highs expected to range from the low to mid
20s north and mid 20s to near 30 central and downeast. However,
today's milder temperatures will be short lived, as yet another
arctic frontal boundary will be approaching from the west late
this afternoon. The front is expected to reach the Maine/Quebec
border late this afternoon and then cross the region this
evening. The arctic front may be accompanied by some scattered
evening snow showers or perhaps a brief squall. Strong cold
advection behind the front tonight will result in low
temperatures falling to 10 below to 15 below across the north
and the single digits above zero central and downeast. A Wind
Chill Advisory remains in effect for northern areas beginning
late tonight.


Another high residence arctic air mass will move into the FA
from N Cntrl Can Sat morn with clrg skies and sharply colder
temps on very brisk NW winds, with wind chill advs for Nrn ptns
of our FA until erly aftn, at which points winds should
diminish below 10 mph. Expect the coldest daytime hi temps of
the season so far, with many lctns across the far N not getting
abv 0 deg F.

High clds will eclipse the FA from the SW by late Sat aftn as
an important low pres from the SW conts to organize as it apchs
from the SW. Clds from this system will thicken Sat eve/ovrngt
with sn moving into SW ptns of the FA late Sat ngt and erly Sun
morn with snfl beginning for many lctns with temps well below
zero F with actual lows by mdngt at most lctns, then temps
slowly rising by daybreak.

Latest trends from the longer range models by tngt's 00z model
run suite indicate a slightly further S track of the coastal
sfc low to affect our Rgn Sun and Sun ngt ovr recent prior model
runs, likely due to the depth of arctic air xpctd to be
entrenched ovr our FA prior to this event. Precip type will be
all sn for Nrn, E Cntrl, and most likely the lower ptns of the
Penobscot Vly of the FA, with a mix of sleet and/or fzra still
possible later Fri aftn/erly eve for SE ptns of the FA as far
N alg the NB border as Cntrl Washington county after hvy amt of
sn there as well. A narrow band(s) of sig sleet/fzra accumulation
is possible ovr the SE on top of snfl, with fzra accumulation
(upwards of 3 tenths of an inch) most likely alg the Washington
county coast spcly considering total QPF potential here of
upwards around 2 inches. Storm total QPF drops off to the N to
0.60 to 1.00 inch across the NW and far NE. Winds will be strong
enough to result in patchy blowing and drifting of powdery sn
Sun aftn and ngt N of the area receiving mixed precip.

Hyper low to mid lvl baroclinicity as suggested by 925mb temp
deltas of about 25 deg C from far N to just S of our FA, an
atmospheric sub-tropical rvr bringing unseasonably high PWs alg
the Srn periphery of our FA, and strong upper dynamics with the
upper lvl trof accompanying the sfc low are the main reasons
for squeezing this much moisture out of the atmosphere where
llvl arctic air previously dominated.

Mixed precip will transition back to all sn across the SE Sun
ngt and then taper to sct sn shwrs for all of the FA by Mon
morn. Total sn accumulations will range from 10 to 20 inches,
with highest totals ovr Cntrl ptns of the FA where lclzd reports
of 2 feet are possible, with amts tapering to 10 inches ovr the
far NW where lesser QPF is xpctd, and to the Downeast coast
where sleet and/or fzra will lower amts. Will cont with wntr stm
watches for this update, with transition to wntr stm wrngs
likely for part or all of the Rgn by the Fri mid aftn fcst


Another shot of arctic air will arrive into the FA later Mon
with brisk winds contg into Mon ngt with lighter winds with
cont'd snow shwrs. After a cold Mon ngt, some moderation in
temps, and clrg skies for Tue. The next chc for sn or mixed
precip will be Wed and Thu as low pres system(s) from the
Midwest apch. Long range models vary widely as to whether only
one system affects our Rgn on Wed or a second as well affects us
on Thu. Given these uncertainties, max PoPs for these days have
been kept to the hi chc cat. Given the amt of arctic air
available or nearby, Nrn and Cntrl ptns of the FA are depicted
to have all sn with Downeast areas shown to have sn chgng to a
sn/rn mix. Temps in particular are very uncertain, spcly Thu
where models vary as to whether arctic air will or will not be
ovr the FA.


NEAR TERM: VFR conditions early this morning will quickly give
way to MVFR/IFR in developing light snow at all terminals this
morning into this afternoon. An arctic cold front will cross the
region this evening with scattered snow showers possible and
brief MVFR/IFR conditions. VFR is expected to develop all
terminals later tonight.

SHORT TO LONG TERM: VFR conditions are xpctd all TAF sites Sat
and Sat eve. Clgs and vsbys will lower to IFR or less from SW
to NE across the TAF sites by erly Sun morn in sn, contg thru
the day Sun and Sun ngt before improving to MVFR conditions on
Mon in sn shwrs. A period of mixed precip is possible for
Downeast TAF sites late Sun aftn into eve. Conditions should
slowly improve to VFR all sites late Mon ngt into Tue.


NEAR TERM: Winds/seas will gradually increase this afternoon,
with Small Craft Advisory conditions expected by tonight. Light
Freezing Spray will be a concern early this morning and then
again late tonight.

SHORT TO LONG TERM: Mostly SCA to sub SCA Sat and Sat eve with
mdt fzg spray likely late Fri ngt into Sat morn. Gale force
winds are then xpctd Sun and Sun ngt ahead of and with the
passage of the nor'easter low pres as it apchs from the SW and
tracks into the Nrn Gulf of ME just S of the waters. Gale force
wind gusts will likely cont into Mon behind the departing low.
Kept close to WW3/NWPS blended guidance for fcst wv hts.


An intense coastal storm is expected to move through the Gulf of
Maine on Sunday generating some storm surge along the Eastern
Maine Coast. In addition to this the astronomical tide is
expected to be close to the highest levels of the month during
the Sunday Morning high tide cycle between 9:15 and 9:45 AM.
Even though the highest storm surge is not expected until later
in the afternoon, tide levels are expected to be high enough
near the time of high tide to result in possible minor coastal
flooding. Even though the largest waves are not expected until
late afternoon, building wave heights along the coast in the
morning may also produce overtopping, splash over, and beach


ME...Winter Storm Watch from late Saturday night through Monday
morning for MEZ001>006-010-011-015>017-029>032.
Wind Chill Advisory from 1 AM to 2 PM EST Saturday for
MARINE...Gale Watch from late Saturday night through late Sunday night
for ANZ050>052.
Small Craft Advisory from 9 PM this evening to 11 AM EST
Saturday for ANZ050>052.



Near Term...Duda
Short Term...VJN
Long Term...VJN
Tides/Coastal Flooding...
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