NWS Caribou, Maine Area Forecast Discussion

FXUS61 KCAR 221549

Area Forecast Discussion
National Weather Service Caribou ME
1149 AM EDT Thu Mar 22 2018

Low pressure will track south of the Gulf of Maine and over
far eastern Nova Scotia today then continue on toward Newfoundland
tonight. A large ridge of high pressure will build into eastern
Canada this weekend and crest over our region early next week.

1140am update...The initial band of snow is currently over the
Bangor and Down East regions and gradually weakening as it moves
into drier air. A shortwave rotating into Nova Scotia is
expected to rotate towards the Bay of Fundy and add some
reinforcing moisture in the trowal towards coastal Washington
and Hancock County...where a grand total of around 5 inches
could fall for this storm. The good news is that shortwave
rotating into Nova Scotia is far enough north to mitigate all
earlier concerns about much heavier amounts. North of Bangor,
Hancock County, and Washington County, snow amounts have been
reduced to a trace or less. Will maintain the current advisories
for this ongoing event. Also reduced today`s high under the
denser cloud cover in the southern half of the forecast area
while increasing highs towards Caribou and the St John Valley
where only thin stratocu is reducing sfc htg.

Orgnl Disc: For now, no chgs to the current wntr wx adv area
for sn/blsn currently ovr all of Hancock and Washington counties
til 4 pm. Of all of the 00z dtmnstc models, only the ECMWF
gives sufficient QPF thru the 18-00z tm frame tdy to result in
snfl to warrant the adv ovr this ptn of the FA. Most of the
others now keep better banding of snfl just S of SE ME, so there
is a chc we may be to canx advs for part or all of th wntr wx
advs early. Also, practically all models do not get the leading
nrn edge of snfl past a Mars Hill- rn Baxter St Park line erly
this aftn before sn retreats ewrd into NB prov late this aftn.
This lead us to lower PoPs a little to chc or less across the NW
and far NE with little mention of accumulation.

In any event, whats left of steady snfl should be exiting into
NB prov by late aftn leaving sct sn shwrs N and Cntrl and sct
rn/sn shwrs Downeast with all shwrs ending this eve as winds
subside and skies partially clear by erly Fri morn. Hi temps
tdy will be a little below avg for this tm of season due to cld
cvr and potential snfl with abv avg ovrngt lows with initially
little in the way of colder air behind the departing low.

Low pressure will be tracking up across Newfoundland on Friday as
the upper trough progresses through the northeast. An upper low
embedded within the trough will be dropping south into New York
state Friday while a small shortwave ridge east of that low pushes
across our area. This should allow partial sunshine with seasonable
high temperatures in the mid to upper 30s. A strong ridge of high
pressure will begin building into east central Canada on Saturday
while a trough over the Maritimes hangs back across our region. Some
moisture embedded within the trough combined with an upper shortwave
low dropping south, just to our west, may produce snow showers
Saturday. Some briefly heavier snow squalls producing a quick inch
of snow in some central and northern spots are possible during the
midday and afternoon as some instability develops in the low levels.
The snow showers may also be supported by an inverted trough
extending north through the area.

Snow showers should taper off Saturday night as the trough drops
south of the region. A strong, deep ridge of high pressure will then
build down from Canada on Sunday bringing clearing from north to
south across the area. Clear skies and bright sunny days can then be
expected Sunday night through Tuesday as the high crests over the
area. Temperatures will be near normal Monday then a few
degrees above normal on Tuesday. The ridge is then expected to
break down on Wednesday as a weak frontal system pushes in from
the west bringing increasing clouds with a chance for snow or
rain showers.

NEAR TERM: TAF sites from KBHB to KHUL will transition to IFR
ovr the course of the morn in sn/blsn then remain so into the
erly to mid aftn before improving back MVFR late this aftn in
sct sn shwrs and then to VFR tngt as sn shwrs end and clgs lift.
Nrn TAF sites will begin VFR erly this morn, then potentially
transition to MVFR in intermittent lgt sn/blsn late this morn
contg into the aftn before improving to VFR tngt. KFVE may cont
to have MVFR clgs into the ovrngt.

SHORT TERM: VFR conditions are likely Friday into Friday night.
MVFR to occasionally IFR conditions in snow showers are likely
Saturday. Conditions should improve to VFR across the north
Saturday night then over the rest of the area Sunday. VFR
conditions in clear skies are expected Sunday night into

NEAR TERM: Gale wrngs cont across our waters with a transition
to an SCA xpctd some time this eve as winds subside. Went about
2 to 3 ft abv the WW3/NWPS guidance blend for tdy, merging
closer to guidance late tngt. Vsbys will ocnly be less than 1 nm
attms due to falling sn spcly this morn into the midday hrs,
with vsbys improving this aftn and tngt as precip becomes shwry
and then ends.

SHORT TERM: A SCA may be needed Friday morning for north winds
gusting up to 25 kt. Winds should then be below SCA Friday
afternoon into Saturday, then increasing to SCA in northeast
winds gusting up to 25 or 30 kt Saturday night into Sunday.

ME...Winter Weather Advisory until 4 PM EDT this afternoon for
MARINE...Gale Warning until 6 PM EDT this evening for ANZ050>052.

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

NWS CAR Office Area Forecast Discussion