365
FXUS61 KCAR 271509
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1109 AM EDT Thu Jun 27 2024

.SYNOPSIS...
Low pressure will exit across the Maritimes this afternoon
drawing a cold front across the region. 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/...
Update...
Low pressure will exit across the Maritimes through the
afternoon, drawing a cold front south across the forecast area.
An upper level trof will also approach, from the west, later
this afternoon. The steady rain has now exited across the
Maritimes with the surface low. Expect scattered/numerous
showers across northern areas through the afternoon, with
scattered showers Downeast. Temperatures will cool aloft through
the afternoon with the approaching upper level trof, leading to
steepening lapse rates. Increased instability with the
steepening lapse rates, along with the cold front, will also
support the possibility of isolated thunderstorms this afternoon
into the evening. High temperatures today will range from the
mid 60s to around 70 north, to around 70 to the mid 70s
Downeast. Have updated to adjust for current conditions along
with expected afternoon temperatures, clouds and
shower/thunderstorm chances.

Previous Discussion...
An upper level trough will propagate towards the area today. 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.

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 /15Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR possible along the Downeast coast through late
morning. Otherwise, expect generally VFR/MVFR this afternoon
into the evening with scattered to numerous showers. Variable
conditions with any isolated thunderstorms this afternoon into
the evening. Otherwise, VFR tonight. Variable winds 5 to 10
knots, becoming west/northwest today. West/northwest winds
around 10 knots tonight.

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: Winds/seas below small craft advisory levels this
afternoon through tonight. Scattered showers into the evening.
Isolated afternoon thunderstorms are also possible. Patchy fog
also persists into the evening.

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...None.

&&

$$


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