-- Discussion containing changed information from previous version are highlighted. --
791
FXUS61 KCAR 270014
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
814 PM EDT Sun May 26 2024

.SYNOPSIS...
High pressure will build to the east of the region through
tonight. A warm front slowly approaches from the southwest
Monday and Monday night, as low pressure slowly moves into
Quebec. This low lifts slowly northeast into central Quebec
Tuesday and Tuesday night, then slowly moves to the east into
the Maritimes through Thursday.

&&

.NEAR TERM /THROUGH MONDAY/...
7pm Update...
Forecast on track with only minor tweaks to the forecast.
Daytime cumulus and towering cumulus are dissipating as we
begin to lose the sun. Quiet this evening, but as a moist low
level SE breeze kicks in later tonight, still expecting low
clouds to form.

Previous Discussion...
The upper level ridge will settle over the region tonight. RH
models show the skies beginning to clear, then the lower cloud
layers moving in after midnight. Moisture is expected to
increase with the approach low pressure system, thus Downeast
will see the lowering ceiling first with patchy fog developing
after midnight. Temps expected in the upper 40s.

By Monday, the center of the occluding low pressure moves across
the Great Lakes swinging with initial rain showers towards the
region. Models are in good agreement with some drizzle to light
rain showers across the coastal Downeast in the morning and
early afternoon before the rain showers continue to move from
west to east across the region. Temps are expected to be fairly
cool Monday with temps in the mid 60s in the north and low 60s
in the south.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A warm occlusion moves through the area with locally heavy rain.
Embedded thunderstorms are possible given the expected elevated
instability. PWs climb to over 1.5 inches with strong mid-level
moisture transport northward into the area later Tuesday night.
The 850mb jet will likely reach a magnitude in excess of 50 kt.
WPC maintains a marginal risk in the ERO through Monday night.
In terms of hydro risks, the system looks fairly progressive and
QPF is expected to max out around an inch and a quarter in
upslope areas of Piscataquis County. Nonetheless, embedded
convection and training cells have the potential to cause
issues.

The heavy precip will exit eastern Maine Tuesday morning. The
warm occlusion is expected to leave a veneer of low clouds under
a fairly strong low level inversion that will erode very slowly
from the west later Tuesday afternoon. That will keep highs in
the upper 60s in much of eastern Maine, but towards the North
Woods, some clearing is possible with highs reaching the low to
mid 70s.

This clearing will present an opportunity for rapid
destabilization. Dew points will remain in the low 60s. While
SBCAPE values may not be too impressive, forecast deep layer
shear is very impressive as a strong upper jet rounds the base
of the upper trough. The combination of low LCLs and this amount
of shear has proven to be a potent combination for severe
weather in late May of years past. Any storms that form in the
North Woods would tend to weaken as they move towards eastern
Aroostook and the more stable environment expected there into
late Tuesday afternoon.

Drier air slowly filters into the area Tuesday night, but some
fog may reform for Downeast on Tuesday night. While the upper
trough remains over the area Wednesday and showers are
definitely a risk with a secondary cold front in the afternoon,
shear rapidly decreases Wednesday morning and SBCAPE looks quite
modest. Mid-level warming may cap convection for the most part.
Highs will reach the low to mid 70s, representing the warmest
day of the week.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The long term is relatively uneventful and cool under the
influence of an upper trough. The combination of the cool upper
trough and chance that a cut-off upper low could park over the
area later this week led to elevated PoPs for showers. The north
to northwesterly flow and expected 850mb moisture will likely
led to cloudy intervals, especially in northern zones. The trend
will be towards more sun by the end of the week.

High temps will be in the mid to upper 60s with lows in the
40s. Offshore winds will help push the upper 60s close to the
coast, but the flow will likely be too weak to prevent afternoon
sea breezes. Lower humidity arrives Wednesday night in the
aftermath of a secondary cold front.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR this evening and early tonight, then conditions
decrease to MVFR/IFR a bit after in low cigs. A few hours
uncertainty in the timing of the onset of the low cigs, but high
confidence that they will occur at all sites. Light E breeze.
For Monday, generally starting out IFR from low ceilings
areawide, with the ceiling slowly rising to MVFR by midday for
most places. A few places could see low VFR ceilings in the
afternoon, but most areas will stay MVFR through the afternoon.
Light rain will begin to move in toward 0z Tuesday. SE winds
increase to 10-15 kts. LLWS also developing BHB/BGR toward 0z.


SHORT TERM:
Monday night into early Tuesday morning...IFR due to cigs and
occasionally heavy rain. Isolated embedded thunderstorms. LLWS
likely. Southeast winds 10 to 15 kt.

Tuesday afternoon...MVFR cigs becoming VFR by evening. Chance of
thunderstorms...mostly towards GNR and Clayton Lake in the
afternoon.  South winds 10 to 15 kt.

Tuesday night into Friday...Generally VFR. SW winds 5 to 10 kt
on Wednesday trending towards NW winds 5 to 10 kt Thursday and
Friday.

&&

.MARINE...
NEAR TERM: Winds and seas will remain below SCA conditions
tonight. For Monday, winds will gradually increase into the
early morning where gusts will reach SCA levels and continue
through the rest of the day. A Small Craft Advisory has been
issued for Monday afternoon. Seas 3-4 ft.

SHORT TERM: A Small Craft Advisory is in effect for Monday night
and will likely need to be extended into Tuesday morning for
winds and seas. The seas may stay above the 5 ft advisory
criteria until later Wednesday. Fog can be expected at times
Monday night into Wednesday. There is a chance of thunderstorms
Monday night into Tuesday morning.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
ME...None.
MARINE...Small Craft Advisory from 11 AM Monday to 8 AM EDT Tuesday for
     ANZ050>052.
-- End Changed Discussion --

&&

$$


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