088
FXUS61 KCAR 152306
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
706 PM EDT Mon Jul 15 2024

.SYNOPSIS...
Several weak troughs of low pressure will cross the area through
Tuesday. A cold front approaches the area Tuesday night, then
slowly crosses the region Wednesday and Wednesday night. An
upper level disturbance passes on Thursday with high pressure
building in through Friday.

&&

.NEAR TERM /THROUGH TUESDAY/...
655 pm update...Removed mention of fog inland tonight. Also
removed mention of showers and thunderstorms this evening. Added
thunderstorms later tonight into Tuesday morning. Updated PoPs
into Tuesday morning based on the eastward progression of the
MCS currently in upstate NY and Quebec. The MCS represents a big
challenge for Tuesday in terms of how much instability
develops...both due to cloud cover and the cold pool aloft. CAMS
generally has the remnants moving across northern Maine in the
morning, leaving the question of whether instability redevelops
in the afternoon...and if a 2nd MCS currently in Iowa can reach
the area by evening. Cloud could also nudge Tuesday high temps
downward a bit...a trend noted in the NBM compared to guidance
of recent days.

Previous discussion...
Hot and humid conditions exist over most of the area though the
immediate shoreline and outer islands remain in the 60s. Dwpts
remain in the middle to upper 60s and will only climb throughout
the nighttime hours. Only isolated showers this afternoon,
though cannot rule out an isolated lightning strike later this
afternoon or evening.

Line of thunderstorms developing ahead of front over Quebec
should begin to dissipate with loss of diurnal heating before
heading into the Crown of Maine. More potent complex of storms
over western NY expected to survive into srn New England late
tonight but gradually dissipate as it heads into Maine after
08z. Dewpoints will remain anomalously high throughout the
overnight with temps only able to dip into the u60s.

Hires guidance is all over the place with resultant MCV left
behind by complex as it moves into New England tonight. Majority
of guidance has it moving northeast into nrn Maine after
daybreak with showers moving through initially as storms develop
late in the morning due to heating. Strength of the convection
depends on the amount of clearing in the morning with progged
CAPES of around 1000 joules. 0-6km shear will be increasing
during the afternoon toward 35-40kts but mid-level lapse look to
be marginal.

High temps on Tuesday in the middle to upper 80s over inland
locations with dewpoints reaching into the lower 70s will keep
heat indices in the lower to middle 90s. The only place where
we will confidently hit heat advisory criteria (HI>95 degrees)
is in southern Penobscot. Cannot rule out a couple of hours of
around 95 heat index for the Dover and Lincoln areas but
confidence is a little too low to issue an advisory for these
areas and will allow later shifts to get a better idea on how
high the temps and dwpts will be.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
The upper level trof will swings a very weak low pressure
system into the area Tuesday night. A very weak warm front is
expected to lift across the north bringing warm S flow and
keeping nighttime temps in the upper 60s to low 70s. In
addition, showers should continue across the region, but mainly
in the north near the frontal boundary. By Wednesday, the center
of the low pressure should move NE, bringing the weak cold
front across the area. Showers are expected to continue
throughout the day with temps reaching into the upper 80s across
the area. With the moist environment, heat indices could reach
into advisory level by the afternoon. In addition, upper air
model soundings show an increase in instability with the
prefrontal boundary. With CAPE >1000 J/kg and bulk shear >35
kts, some thunderstorms could become severe. However, lapse
rates are fairly weak at low and mid level, which could keep
some storms from building. Localized heavy rainfall is expected
with the increasing PWATS, long skinny CAPE in the column, and
high RH in the low and mid levels.

By Wednesday night, the cold front is expected to move through
changing winds to W flow and pushing temps into the mid 60s.
Showers should continue through Thursday where temps are
expected to be much cooler on the upper 70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
High pressure is expected to move into the area Thursday night
and stick around through Saturday night. A much cooler upper
level airmass is expected to move through on Friday bringing
temps into the upper 70s with sunny skies. The next frontal
system is expected on Sunday, but the models lose consistency
with the timing of the system. The beginning of next week looks
less active. Expect temps near normal for the weekend.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
645 pm update...Fog appears to be offshore, south of BHB, and
expect it roll onshore to BHB later tonight. However, will be
watching carefully for an earlier arrival. The fog/stratus will
probably reach BGR after daybreak for a brief time. The bigger
concern Tuesday will be strong thunderstorms, potentially
embedded, that could start as early as Tuesday morning.

NEAR TERM: VFR for northern terminals next 24 hours. May see
vcsh this afternoon and again after 12z Tuesday. Downeast
terminals likely to see IFR overnight in low cigs and fog. BHB
may drop to LIFR between 07z-12z. Improvement expected after
mid-morning for southern terminals.

SHORT TERM: Tue night-Wed...MVFR to possible IFR in rain
showers. Isolated thunderstorms, some strong, Wed afternoon. SW
winds 5-10 kts.

Wed night-Thu...Mainly VFR with possible MVFR in rain showers.
W winds 5-10 kts.

Thu night-Sat...VFR. WSW winds 5-10 kts.

&&

.MARINE...
NEAR TERM: Fog will continue to reduce visibilities tonight but
winds and seas will remain below small craft conditions.

SHORT TERM: Winds and seas will remain below SCA conditions for
this time period. Visibilities reduced in nighttime patchy fog.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from 2 PM to 6 PM EDT Tuesday for MEZ015.
MARINE...None.

&&

$$


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