Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
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FXUS61 KCAR 220318
Area Forecast Discussion
National Weather Service Caribou ME
1118 PM EDT SUN AUG 21 2016
A strong cold front will approach tonight and cross the region
Monday morning. High pressure will build south of the area Tuesday
.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --11:20 PM Update...Raised temps just a bit early in the overnight
period. Otherwise, forecast is on track with band of rain now
moving into western areas. The breeze, moisture and increasing
clouds will keep temps mild overnight.
Periods of heavy rain expected later tonight into Monday morning.
Low clouds and areas of fog over the coastal waters has pushed
its way onshore across the coastal region into portion of interior
Downeast Maine as seen on the latest visible satellite imagery.
Most of this appears to be thinning out per the last few frames.
That onshore flow has kept the coast cool today w/readings only
hitting the upper 60s. Further inland and on n, temps well into
the 70s to around 80 w/the s wind. Clouds will be back on the
increase this evening ahead of apchg cold front. 18Z analysis had
the front draped back across the Ottawa and Ontario region. 12Z UA
showed upper low somewhat paralleling the front, so forward
progress of the front will be slower than what the guidance is
advertising. Therefore, backed up the timing of the rainfall by a
least 2 hrs given this setup. Atmosphere is forecast to moisten up
overnight w/pwats hitting 1.5+ inches w/a ssw flow through the
column. A jetstreak of 40 kts residing at 700mbs will aid in the
forcing w/potential for heavy rainfall. Leaned against convection
overnight into early Monday as elevated instability marginal
especially elevated CAPE around 200 joules at best.
A wave of low pres is still be shown by the short range guidance
including the NAM12 and GFS to link up on the front early Monday.
This will keep steady rain going a while longer and hold up the
front some. Based on this thinking, kept steady rain going into
late morning and then transitioned things to showers. Some
instability is around early but again marginal, so attm, stayed
away from the mention of thunder. The later shifts can assess this
further w/the latest guidance. Collaborated w/the NERFC and GYX on
rainfall amounts and generally 0.50 to 1.00 inches basin
average. Some sites could see 1.25 inches especially in the
upslope areas such as Mt. Katahdin and the Piscataquis region. It
will be much cooler on Monday w/daytime temps in the lower to mid
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.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
pressure will to build in from the west Monday Night. This system
will then pass to the south of New England Tuesday Night then move
to the east into the Atlantic Wednesday and Thursday. This system
is expected to bring dry conditions into Thursday.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A cold front will approach from the west Thursday Night then cross
the region Friday bring some showers. A weak area of low pressure
may develop along this front as it moves through keeping showers
over the region into early Saturday. Strong high pressure is then
expected to move in from the west late Saturday and Sunday.
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR for the northern terminals this evening going to
MVFR and then IFR into late Monday morning. A quick improvement is
expected by the afternoon to MVFR and then VFR. For KBGR and KBHB,
MVFR going to IFR tonight into Monday morning. Improvement expected
to VFR by later in the morning.
SHORT TERM: Expect VFR conditions Monday Night through Wednesday
Night. MVFR conditions are expected Thursday.
NEAR TERM: No headlines this period. S winds are around 10 kts
attm w/seas of 1-2 ft. A slight build in the seas is expected
overnight w/heights going to 3 ft as winds increase to around 15
kts. Winds to veer to a w direction Monday afternoon w/speeds
dropping off and seas coming down to around 2 ft.
SHORT TERM: Have used the NAM12 to initialize the sustained winds
Monday Night through Wednesday then transition to the Super Blend
Winds. For Waves: There continues to be some very long period
swell generated by tropical system well to the south and east of
the waters, however the wave height from this wave group is under
1 foot. The primary wave group from Tuesday night through Friday
will continue to be dominate by local wind wave. Will populate
wave grids with the Near Shore Wave Model through Wednesday.
Boundary conditions look reasonable so will not make any
adjustments. Will transition to the Wave Watch III late Wednesday.