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000
FXUS61 KCAR 252007
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
407 PM EDT Sun Jul 25 2021

.SYNOPSIS...
A warm front will lift across the area tonight. A cold front
will cross the area on Tuesday. High pressure will build over
the area Wednesday. Low pressure will approach on Thursday.
&&

.NEAR TERM /THROUGH MONDAY/...
The warm front and transition to a more humid air mass is the
dominant feature tonight into Monday morning with fog developing
across the entire area tonight. A Dense Fog Advisory may be
needed but will hold off for now. Rain will taper off by early
evening ahead of the warm front, but light rain and drizzle is
certainly possible throughout the night. Later tonight, an upper
level shortwave will cross the area. This shortwave is currently
associated with thunderstorm activity in southern Ontario and
western Quebec. Although not all guidance shows it holding
together across the northern half of the forecast area later
tonight, some CAMS output has shown it for days and continues to
do so. There`s some decent cooling aloft while a low level
thermal ridge builds at the top of the frontal inversion
tonight. This generates some elevated CAPE later tonight and
shear also increases. Will maintain mention of isolated
thunderstorms across Aroostook County late tonight into early
Monday morning. Low clouds and fog will slowly burn off Monday
morning. By this time the occluded front has moved across the
area, leaving a much warmer and humid air mass. The morning low
clouds will slow production of SBCAPE, but eventually there
should be sufficient instability for isolated to scattered
afternoon thunderstorms. The best CAPE and shear will be in
southern Penobscot County and interior Downeast for a brief time
in the early to mid afternoon. Shear looks marginal for strong
storms. There`s also the remnants of the washed out occluded
front in that area. There`s several factors inhibiting
convection such as very dry air aloft, lack of a decent upper
level shortwave like earlier in the day, and a cap near 500mb.
Will mention thunderstorms across the area in the afternoon, but
hold off on enhanced wording.

Smoke is the other emerging issue for Monday. Have not added
smoke or haze in the gridded forecast database at this time, but
HRRR guidance and METSAT imagery shows smoke from Manitoba and
Ontario fires heading this way...and it may mix towards the
surface by Monday morning. That usually generates a lot of
confusion and concern from the public. By the time clearing
occurs later Monday morning into the afternoon, the smoke will
likely be more noticeable.
&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
Area wl be split btwn two fronts on Mon evening. Cannot rule out
lingering showers over srn and nrn areas with an isold tstm
still possible but coverage wl likely be on the decrease with
loss of diurnal htg. Given moist and humid airmass still in
place wl likely see areas of fog acrs the area Mon night.

Depending on how quickly high pressure builds south out of
Canada Tue morning wl determine where storms wl develop in the
aftn as s/wv heads south and east out of Canada. This wl allow
storms to develop along front dropping thru the CWA and shud
allow storms to develop across central and srn zones aft 18z.
Given the uncertainty have hesitated to call it chc showers and
tstms and hv only worded it as isold tstms until details can be
better ironed out.

Secondary front wl mv offshore Tue evening with showers winding
down aft midnight along the coast. Patchy fog expected to
develop acrs the north as skies clear but drier dwpts may
prevent fog to increase in coverage drg the overnight. Downeast
coast may see patchy fog as well as humid airmass rmns in place,
however skies wl still be cldy and prevent more widespread
coverage.

Sfc high pressure wl be building into nrn New England with cool
northerly flow draining out of Canada. Skies will be mocldy on
Sunday with nw winds ocnly gusting drg the afternoon.
&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Flow rmns out of the nw aloft thru Wed night and wl gradually
transition to a s/wv ridge acrs Maine Thu morning. Sfc high
pressure wl be building well offshore Wed night and with skies
clearing and light winds cannot rule out areas acrs the
northwest dipping into the mid-40s.

Next system wl be heading in fm the west and guidance fairly
consistent in bringing showers, possibly stratiform rain, in wrn
areas on Thu afternoon. Rain continues Thu night with showers
expected especially across the north on Friday as upr lvl trof
mvs thru Quebec into the Maritimes. Temps likely to be below
normal thru the end of the long term and into next weekend.
&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: Conditions to continue to deteriorate this evening to
IFR and then LIFR due to low cigs, drizzle and fog. Fog is most
likely for GNR towards HUL and points south...especially on the
coast. FVE will also have fog. LLWS is expected late this
afternoon into the early evening. Thunderstorms are possible
north of HUL and GNR after midnight into early Monday morning.
Isolated afternoon thunderstorms are expected Monday afternoon
after morning fog and low clouds dissipate.

SHORT TERM:
Mon night...Potential IFR in areas of fog developing late at all
terminals. Light WSW wind.

Tue...Becoming VFR late morning with localized MVFR restrictions
in -tsra, mainly at HUL and BGR. W 5-10kts.

Tue night...VFR early, decreasing to localize IFR in fog late.
NW 5 kts.

Wed-Wed night. VFR. NW 5-10kts Wed becoming light SW Thu
morning.

Thu-Fri...Lowering to MVFR/IFR in rain and fog. S 5-10kts,
becoming SW Fri morning.
&&

.MARINE...
NEAR TERM: Fog will thicken and become more widespread tonight
and slowly move offshore Monday afternoon...returning again in
the evening. Winds will pick up this evening to as high as 20
kts, but fall short of advisory criteria. These south winds will
generate south seas hitting up to 4 or 5 feet tonight, but also
below advisory thresholds.

SHORT TERM: Winds and seas to remain below SCA thresholds
through the week. Expect that humid airmass will bring areas of
fog to the waters Mon night and Tue night before a cold front
crosses the waters Wed morning.
&&

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

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