339
FXUS61 KCAR 111006
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
606 AM EDT Sat May 11 2024

.SYNOPSIS...
High pressure builds across the region through Saturday night.
A warm front approaches Sunday, then lifts to the north Sunday
night and Monday. A storm system approaches from the west Monday
night and Tuesday then crosses the region Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
606AM Update...No major changes to the forecast for this
update.

Previous Discussion...
A very weak upper level trof will help keep surface ridging
over the region for today and tonight. For today, vorticity
models show a vort max sitting over the region this morning,
which will help with the increase in low level clouds. The 925mb
model temps show the cold pool starting to sag to the south
flowing the surface ridge, which should help temps increase into
the upper 50s this afternoon despite the cloud cover. By the
afternoon, clouds are expected to decrease slightly, which could
help with afternoon convection. Upper air model soundings
indicate instability with higher CAPE values and steep lapse
rate. However, the mid-level warm air will help drive down
convection, thus thunderstorms are not expected. Isolated
showers will increase from the south to the north into the
evening.

By tonight, the ridge starts to weaken, which will help keep
cloud cover across the south, but decrease in the north. Temps
in the north could reach towards freezing, however, if the
clouds return later in the night, then temps will hover just
above freezing.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Quiet weather is expected through the period. On Sunday, an
upper low will be over the area, but high pressure at the
surface. Little moisture will be available for shower activity
beyond a few sprinkles, but enough 850mb should be in place for
partly to mostly cloudy skies on Sunday. The clouds will help
limit highs to around 60F. Light winds and clearing skies will
promote strong radiational cooling Sunday night as lows drop
into the 30s. The frost/freeze program will be in effect for
Bangor and Downeast by Sunday night, but temps do not look cold
enough for frost at this point.

Upper level ridging builds Monday and the surface high builds
east of the area. Temps will warm to the low to mid 60s. That
could generate some modest instability in the 850 to 700 mb
layer with partly cloudy skies and a few sprinkles.

Clear skies and light winds will allow a shallow radiation
inversion to develop Monday night with lows dropping to the
lower 40s, but clouds increase later in the night ahead of an
approaching warm front. Cannot rule out rain by late night, but
with very dry air in place and upstream blocking, the front will
make slow progress.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A wetter and warmer pattern emerges in the long term. Blocking
the the Atlantic will keep a slow-moving frontal system in the
area Tuesday and Wednesday...possibly into Thursday. In general,
a northern stream warm front moves into the area Tuesday. A
trailing cold front then moves into the area Tuesday night and
stalls. At that point, deep southern stream moisture is pulled
northward along the stalled boundary into Maine late Tuesday
night into Wednesday night. There is potential for an inch or
two of rainfall, but it is still uncertain exactly where the
front stalls and where that heavier precip is focused. Given the
uncertainties, have capped PoPs at 70 percent or less Tuesday
into Wednesday and went with a more progressive NBM solution to
push rain out of the area Thursday. Part of the uncertainty for
Wednesday night into Thursday revolves around how the southern
stream system phases with the northern branch. In the case of
ECMWF, the southern stream system becomes a vertically stacked
cut off south of the area and precip ends earlier than GFS and
GEMS solutions.

Once the system does move out Thursday into Friday, the
expectation is for mild temps and upper ridging. Readings in
the 70s would be possible by next Friday.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: Mainly VFR conditions for today and tonight. For
today, light ESE winds. For tonight, possible MVFR cigs for BGR
and BHB in increasing cloud cover. Light and variable winds.


SHORT TERM:
Saturday night through Monday night...VFR with light winds

Tuesday into Wednesday...MVFR tempo IFR due to cigs and vis
reductions in rain. South winds 10 to 15 kt. LLWS possible
Tuesday night.

&&

.MARINE...
NEAR TERM: Winds and seas will remain below SCA conditions for
today and tonight.


SHORT TERM: Quiet conditions until Tuesday when fog becomes
increasing likely. Long period south swell Tuesday night into
Friday could be over 5 ft and necessitate a Small Craft
Advisory.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.

&&

$$


Near Term...LaFlash
Short Term...MCW
Long Term...MCW
Aviation...LaFlash/MCW
Marine...LaFlash/MCW