Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
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FXUS61 KCAR 251553
Area Forecast Discussion
National Weather Service Caribou ME
1153 AM EDT Sun Sep 25 2016
High pressure to the west of Maine will build into the area
through Monday morning. The high will move out into the Atlantic
Monday afternoon. An occluded front will cross the area Tuesday.
Areas of low pressure will pass south of the region mid to late
.NEAR TERM /THROUGH TONIGHT/...
Frost is the big story tonight with all zones vulnerable except
along the coast. Have lowered temperatures for the entire area in
this update and introduced widespread frost terminology in the
forecast. A hard freeze is probable towards northwest Aroostook
where lows in the 20s are expected. No additional frost or freeze
warnings will be issued for Aroostook County...northern
Piscataquis and northern Somerset counties based on reasons
outlined in the NWS Caribou Public Information Statement issued
High pressure across Quebec province will build slowly
east today. At the same time, an upper low near Labrador will move
slowly east away from the region. Expect partly sunny skies across
the north today and mostly sunny downeast. There may also be an
isolated shower or two through midday, mainly across the St. John
Valley. It will be another unseasonably chilly fall day. Highs
across the north will only range from the low to mid 50s north and
the mid 50s to near 60 downeast.
High pressure will continue to build east tonight. The
combination of mainly clear skies and light winds will result in
areas of frost developing across most of the region away from the
downeast coast. A frost advisory has been issued for all of
central and interior downeast Maine for late tonight. Although
areas of frost will also be possible across the north, no
advisories will be issued there due to the termination of the
program for the season. Expect lows tonight to range from the low
to mid 30s north, and mid to upper 30s central and downeast.
.SHORT TERM /MONDAY THROUGH TUESDAY/...
An upper ridge axis across Lake Ontario at 12Z Monday will move east
into western New England by Monday evening, and will continue to the
east of the area by Tuesday morning. A surface high settles into
Maine Monday morning and will move off the New England coast Monday
afternoon. Low pressure across the northern Great Lakes Monday
evening will drift southeast with an occlusion in western New York
State Monday evening to move into western New England late Mon night
and into Maine Tuesday. A weak secondary low may try to develop
Tuesday. As far the sensible weather goes, Monday will be bright
and sunny. After a frosty start at many inland areas, temperatures
will rebound to seasonable levels in the afternoon. Clouds increase
Mon night with the chance that a little light rain breaks out
across the western zones between midnight and daybreak Tuesday.
The increase in clouds will greatly reduce any frost potential,
with about the only spots that could see any frost in the valleys
near the New Brunswick valley where the clouds will be the slowest
to move in late at night. Rain will move east and across the area
during the day Tuesday. The rain does not look to be particularly
heavy with most areas to likely receive anywhere from a tenth to a
third of an inch, with the highest totals expected toward the Down
East coast. The clouds and rain will highs mostly in the 50s
across northern areas to the lower 60s in the Bangor area.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The occlusion will move east of the area Tuesday night. Rain is
expected to end by early evening for most of the CWA, but may linger
till around midnight in eastern areas. Wednesday should feature a
mix of sun and clouds and milder weather with above average
temperatures. Although a shower can`t be ruled out, most of the day
looks dry. Forecast uncertainty increases late week and upper
trough moves east. There is significant model spread as to whether
the low moves toward the New England coast or ends up much further
south and west in the lower Ohio or tennessee Valleys. The model
ensembles have significant spread, so forecaster confidence is
very low. If the low is further north, a surface low could produce
more showers/rain. A more southern solution would mean a dry
pattern late in the week. Given the high levels of uncertainty
will stick close to the ongoing forecast, which has mostly slight
chance/chance PoPs late in the week. The afore mentioned uncertainty
will continue into Saturday too, with the more northern
solutions wet, and a more southern solution dry. Temperatures are
likely to be above average late in the week into the start of the
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR through tonight. Brief MVFR cigs are possible
across the northern terminals through mid morning.
SHORT TERM: VFR Monday into Monday night outside of any early
morning river valley fog Monday morning. Conditons will lower to
MVFR with pockets of IFR Tuesday as rain overspreads the region.
Conditions will improve to high end MVFR or VFR by later Tue night
and into Wed. Forecast confidence is very low late in the week
with VFR favored, but if rain moves into the area lower ceilings
NEAR TERM: Winds/seas will remain below small craft advisory
levels tonight although a few gusts to around 25 kt are possible
SHORT TERM: A small craft advisory might be required by late Tuesday
as seas build ahead of an occluded front.
ME...Frost Advisory from midnight tonight to 7 AM EDT Monday for