Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCAR 180219
Area Forecast Discussion
National Weather Service Caribou ME
1019 PM EDT Mon Oct 17 2016
High pressure will build across the region tonight. A warm front
will approach tonight and lift across the region on Tuesday. A
cold front will cross the area Tuesday night. High pressure
returns for Wednesday.
.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --1000 PM Update: Hi cld cvr has now nearly entirely eclipsed our
FA, so for now temps have lvld off from falling. IR Sat imagery
does show another break in clds ovr Srn QB that could make it into
wrn ptns of the FA ovrngt before thicker cld cvr with rn arrives
by daybreak, so cannot say for sure whether temps will fall a
little more or not...so fcst lows remain unchgd for now. For now,
we moved ovrngt lows in the 1-2am tm frame, and have temps slowly
Orgnl Disc: The cold front has crossed the forecast area and has
entered the Gulf of Maine. The high will build through tonight
with increasing clouds for most of the area later tonight. Expect
lows will dip to the low to mid 30s in the Crown of Maine before
the clouds increase, but only drop to the mid to upper 40s towards
Bangor and the Down East coast. The cold front will return
northward as a warm front Tuesday. With the stable nature of the
precip and the frontal inversion, have changed the description of
the precip to rain and lowered highs for Tuesday from previous
forecast cycles. Expect upper 40s in the Saint John Valley and
upper 50s for Bangor and Ellsworth. Rainfall should generally be
under a tenth of an inch on Tuesday. Have used a model blend for
QPF...discounting the NAM and its elevated instability. Light rain
and some drizzle seems more likely. The increase in winds under
the inversion is also notable for later Tuesday and have gone with
gusts as high as 25 mph in northern zones. A LLJ with winds of
60-70kt under H850 will be over northern zones later Tuesday, but
it looks too stable to mix these winds to the surface during this
forecast period. Some patchy fog is expected to develop in the
warm sector by Tuesday evening...mostly for the upslope regions of
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.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
It`ll be a rainy start to
the period as rain will be ongoing out ahead of an approaching
front. A strong 850mb jet will lift northward in advance of the
front, helping to spread moisture into the region. This also results
in two concerns: the potential for gusty winds and briefly heavy
rainfall. Convective potential looks minimal given scant
instability. This lack of convection will help limit optimal mixing
of stronger winds to the surface. Regardless, even without
thunderstorms, it will still be a breezy night. PWATs will approach
1.5 inches, so heavy rainfall is possible, mainly across northern
areas. Any heavy rain should be brief, though, and additional
rainfall amounts overnight will be a quarter of an inch or less.
The front will push offshore around daybreak Wednesday, followed by
a drier airmass. As such, expect a dry day with sunshine returning
by afternoon. Temperatures will actually be warmer on Wednesday than
Tuesday by a good 10 degrees. The dry weather will continue
overnight Wednesday night, but the threat for rain returns on
Thursday along with another frontal passage. The bulk of the
precipitation will occur the afternoon. Increased cloud cover will
keep temperatures in the mid 50s to around 60.
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Looking ahead toward the end of the week, our focus will be on a
large trough of low pressure approaching from the midwest and its
interaction with a tropical low approaching the east coast from the
southeast. A large corridor of moisture along the eastern edge of
the trough extending from the Ohio Valley northeast into New England
will push into our area Thursday night with some showers. Moisture
may shift north on Friday as the trough moving into the east
amplifies and potentially becomes negatively tilted. However, low
clouds and drizzle may linger across our region on Friday. The
amplifying trough will open up a channel for the tropical low to
track north toward our area possibly bringing a soaking rain Friday
night into Saturday. There is a small chance this tropical low,
which is only a depression, will develop into a tropical storm.
However, a strong shearing environment along the eastern edge of the
trough is not favoring very strong development. Nevertheless, the
low has the potential to bring ample moisture our way as it lifts
north into our area late Friday night into Saturday. The low will
continue north of our area Saturday night into Sunday as the upper
level low associated with the trough moves over. This will likely
bring continued showers through Sunday and into Sunday night as much
colder air is pulled in from the northwest. Showers will likely
continue Monday, and by Monday night it may be cold enough for some
wet snow showers in the higher elevation in the western and northern
parts of our region. A chilly wind is likely Tuesday with low clouds
and some rain or snow showers across the north and clouds breaking
for some sunshine Downeast.
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions are expected until Tuesday morning.
There is a slight chance of shallow fog at FVE towards sunrise.
Otherwise, all sites will trend down to MVFR and then IFR due to
cigs and rain by midday. Most sites will likely have IFR cigs near
Fl010 during the afternoon into the evening. Very strong winds
under FL050 will materialize later in the afternoon with over 60
kts at FL030 towards FVE and CAR. Even BGR will have nearly 50 kts
at FL020 by evening. LLWS may be needed in TAFs.
SHORT TERM: Widespread IFR conditions are expected Tuesday night
due to rain and fog ahead of a cold frontal passage. Strong winds
will continue through 06z Wed as well, with LLWS possible at all
terminals. The front will push off the coast by 12z or so
Wednesday and expect skies to clear from northwest to southeast as
it does so. Therefore, all sites will be VFR by 16z Wednesday.
These conditions will prevail through 12z Thursday, but ceilings
will lower through the day as more rain spreads into the region.
Expect all sites to be MVFR by 00z Fri. Rainy weather will
continue through Saturday, along with MVFR conditions. Local IFR
will be possible during this time frame.
NEAR TERM: No significant weather until Tuesday afternoon when
some patchy fog is possible and winds will kick up to SCA
criteria with gusts at 25 to 30 kts from the SE. Seas will also
increase towards 5 to 6 feet by evening. As a result, have issued
a Small Craft Advisory as of noon Tuesday through Tuesday night.
SHORT TERM: The Small Craft Advisory will remain in place until early
Wednesday morning. Southwest winds around 20 kt with gusts up to 30
kt are expected through midnight ahead of an approaching front, but
these should subside thereafter once the front crosses the waters.
Seas will peak at 5-7 ft and will be slower to subside. Therefore,
the SCA may need to be converted over to Hazardous Seas only and
extended into Wednesday.
MARINE...Small Craft Advisory from noon Tuesday to 5 AM EDT Wednesday