301
FXUS61 KCAR 270817
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
417 AM EDT Thu Jun 27 2024

.SYNOPSIS...
A cold front will cross the region today while low pressure
moves along the front early this morning. High pressure will
cross the region Friday. A cold front will approach later
Saturday, then cross the region Sunday. High pressure will build
toward the region Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
An initial shortwave is quickly moving through the area early
this morning with a slug of locally heavy rain and isolated
thunderstorms. The upper level trough axis remains in the Great
Lakes region early this morning. Cyclogenesis is currently
occurring along the stalled frontal boundary in the forecast
area. This surface low will quickly eject in the Maritimes this
morning, but the frontal boundary will remain across the area
this afternoon.

The upper level trough will propagate towards the area today
while the stalled frontal boundary acts as a trigger for
scattered showers and isolated thunderstorms. A powerful upper
jet precedes the upper trough this afternoon. This means strong
deep layer shear for storm organization. However, instability
remains in short supply due to residual cloud cover left from
the disturbance this morning. A cap near H6 will have to be
overcome to generate enough CAPE for thunderstorms. This has a
chance of happening Downeast this afternoon with the front as
cooler air aloft arrives with the upper trough. Any storms would
be where dew points remain in the 60s ahead of the front.

Among the models advertising instability...and not all CAMS
are...Downeast appears the most likely to have any strong
thunderstorms. Given the shear, SBCAPE values of just 1000 J/kg
or less could be troublesome. Low freezing levels make small
hail a possible threat if sufficient CAPE can be realized.

A separate area with the threat of late afternoon and evening
thunderstorms will be in northern Aroostook County as the upper
level trough brings steeper mid level lapse rates. CAPE is
nominal for thunderstorms and no severe storms can be
anticipated in northern Aroostook County. The cold air with the
upper trough will drop the freezing level towards H8, so small
hail or graupel is possible.

Highs today will reach the mid 70s ahead of the front. These
temps will occur pretty close to the coast with the southwest
flow preventing a strong onshore flow. Further north in
Aroostook County, highs will only be in the upper 60s due to
cloud cover and cold air advection behind the front.

Showers will linger in northern Aroostook County well into the
night. Cold advection will drop lows tonight to as low as the
upper 30s in portions of the North Woods. Elsewhere, upper 40s
to lower 50s are forecast.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure returns to the region on Friday. This will bring
clear skies and cool temps in the upper 60s. By Friday night,
the warm front from the approaching low pressure system should
stretch across the north. This will increase clouds throughout
the night, as well as keep temps from falling past the low 50s.
By Saturday, the warm front should stretch across Quebec and NB
well to the north, putting the region in the S flow of the
front. By later in the afternoon, rain showers should enter from
the west and spread east throughout the evening and into
Saturday night. Temps should be much closer to normal. By
Saturday night, rain is expected to spread across the entire
region, with most of the rainfall from the system coming during
the night. Patchy fog is expected to develop with the rain.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The low pressure system to the north is expected to swing a
cold front through the region on Sunday. Models are in better
agreement with the timing of the cold front, with the front
exiting Sunday night. The concern for Sunday afternoon will be
the thunderstorm potential. The CAPE environment is expected to
set up ahead of the front with a thin band of >1000 J/kg across
Downeast. The Euro shows the CAPE spreading further north. The
bulk shear is expected to be the driving force of the
thunderstorms with a moist column to produce heavy rainfall.
Better details will come with the system moving into range of
the CAMS.

High pressure should move in for the rest of the week, making
for inactive weather and temps slightly above normal.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
NEAR TERM: A period of IFR vis and cigs is likely early this
morning as locally heavy rain moves across the area. MVFR cigs
are expected to hang on through the morning. These cigs will
lift to VFR at BGR and BHB first...and then further north
during the afternoon. Isolated thunderstorms are possible early
this morning from BGR southward to the coast. Isolated
thunderstorms return this afternoon into the early evening.
Another period of MVFR in showers is forecast for CAR and FVE
later this evening while the remainder of the area stays VFR
through the night.

SHORT TERM: Friday through Saturday...VFR. Northwest
winds on Friday at 5 to 10 will become southerly on Saturday at
10 to 15 kt.

Saturday night into early Sunday morning...IFR cigs and tempo
IFR vis in rain. Isolated embedded thunderstorms. LLWS likely.
South winds 10 to 20 kt.

Sunday...IFR becoming MVFR tempo VFR. Afternoon thunderstorms likely.
Southwest winds 10 to 15 kt becoming NW late afternoon.

Sunday night and Monday...Conditions rapidly improving to VFR.
NW winds 10 to 15 kts.

&&

.MARINE...
NEAR TERM: Longer period south swell has prompted a Small Craft
Advisory into early this morning for Eastport to Schoodic Point,
but expect seas to diminish this morning and do not anticipate
extending the advisory past expiration at 6 am. The south swell
will continue to slowly diminish today into tonight. Southwest
winds under 15 kt continue today, but shift to northwest
tonight.

SHORT TERM: Winds increasing to high end SCA Saturday through
Sunday. Seas building to 6 feet by Sunday, subsiding by early
Monday. Potential for fog Thursday night and again Saturday
night into Sunday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
     ANZ050.

&&

$$


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