Area Forecast Discussion
Issued by NWS Caribou, ME-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCAR 222207
Area Forecast Discussion
National Weather Service Caribou ME
607 PM EDT Thu Sep 22 2016
Low pressure from central Canada will move across the region
tonight into Friday bringing widespread rain to much of the state.
Colder air is expected for the first full weekend of autumn as
Canadian high pressure builds in behind the low.
.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --6 PM Update...Forecast remains on track this evening with rain
beginning to approach far northwestern areas as of 6 PM. Pops were
modified just a bit over the far northwest do delay onset of rain
just a bit where most areas remain dry. Otherwise, no major
changes this hour.
Low pressure currently over the eastern Great Lakes will trek
eastward along a nearly stationary front that lies just across
central New England and off the Maine coast. Rain associated with
this low will spread into northwestern Maine this evening and
eventually across much of the rest of our area overnight. The low
will exit into New Brunswick Friday morning, drawing a cold front
in its wake. The rain will gradually shift southward toward the
coast as the front crosses the state from northwest to southeast,
while the drier air behind the front will bring the precipitation
to a fairly rapid end. As such, northern areas are expected to see
dry weather and maybe even some sunshine Friday afternoon, while
the far Downeast will likely remain rainy through a good part of
the day. The highest rainfall totals will be on the northern side
of the low`s track; locations along and north of a Danforth to
Greenville line will see a half to three-quarters of an inch, with
some spots getting a bit more. South of this line, amounts will be
a half inch or less; the coast will get a quarter of an inch at
most. Tonight`s low temperatures will mainly be in the mid and
upper 40s north to the mid and upper 50s south, though some of the
colder valleys in the North Woods could drop into the 30s. Friday
will be decidedly fall-like as highs will only be in the 50s
across the north and the Central Highlands, while Downeast spots
will be 60-65.
-- End Changed Discussion --
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Fall will show up this weekend as cool Canadian airmass pushes
into the region Friday night behind the surface cold front.
Reinforcing shots of cool air will penetrate into Maine through
the weekend which will bring temperatures below average for this
time or year. Overall it will be partly cloudy on Saturday,
trending to mostly cloudy across the north on Sunday. Cloud cover
will be less across Bangor Region and Downeast with downsloping NW
flow. The question is how cold will it get overnight in regards to
frost development. It doesn`t look to be an optimal radiational
cooling night set-up, with 925mb winds remaining around 25kts
through the weekend. In addition, some low level stratus could
linger around through the night. With that said it is a cold
airmass, so sheltered valley areas could drop below 35 degrees
across Northern Maine. Frost isn`t expected to reach into the
Penobscot Valley or Downeast at this time. A few sprinkles could
be possible on Sunday, but overall it will be a brisk and dry
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Low confidence in the extended forecast with large spread between
the GEM, GFS, ECMWF model families. The large spread is due to a
blocking pattern developing across the North Atlantic. The GFS
camp has a warmer and drier solution next week, with some support
from the GEM. The ECMWF is consistent on bringing in another
trough by Tuesday and keeping it cool and damp through the
remainder of the week. Went with a blend of the solutions at this
time due to large pattern evolution issues.
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
NEAR TERM: VFR conditions will gradually lower overnight as rain
spreads across the region. Ceilings will lower to AOB 1000 ft late
tonight/early Friday from north to south with visibility remaining
4-6 miles. Conditions will then improve from north to south Friday
afternoon as the rain moves toward the coast. All sites will
return to VFR by 00z Sat.
SHORT TERM: Overall VFR conditions expected this weekend with the
possibility of some MVFR cigs across the Northern TAF sites. No
impacts expected at KBGR/KBHB. There could be some gusty winds
that could impact general aviation flights during the afternoon
NEAR TERM: No headlines are anticipated over the next 24 hours. Winds
and seas will build a bit overnight as low pressure slides by to the
north of the waters. However, conditions will remain below Small
Craft Advisory levels with gusts up to 20 kt and seas around 4 ft.
SHORT TERM: No headlines expected this weekend with offshore flow
through the entire weekend. Winds will gusts up to 20kts with
waves up to 4 feet across the outer waters. No fog is expected
with the offshore flow.