298
FXUS61 KCAR 121953
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
353 PM EDT Wed Jun 12 2024

.SYNOPSIS...
High pressure will build south of the region on Thursday.
A cold front will cross the area Friday followed by high
pressure Saturday into Sunday. High pressure will shift south
of the area on Monday.

&&

.NEAR TERM /THROUGH THURSDAY/...
Weak shortwave ridging builds into the region tonight. For this
evening, showers and thunderstorms will slowly start to
dissipate. High-res models indicate that some showers will
linger into the night, but clear out around midnight. With the
continuous calm onshore flow, the marine layer is expected to
return to coastal Downeast and spread into inner Downeast after
midnight. In the north, calm winds and moist soil will also
create patchy fog.

By Thursday, the surface ridging moves to the E with SW flow
increasing. The 925mb temps and wind barbs show the isobars
reaching well into the Gulf of Mexico, bringing the tropical
warm airmass into the area. This will bring temps up into the
low 80s, depending on the cloud cover for the day. Isolated
showers are possible ahead of the approaching warm across the
Crown of Maine in the evening.&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A warm front moves through the area later Thursday night. A
fairly strong 850mb jet will advect much warmer air aloft.
Elevated instability is possible in northern zones by late night
and have introduced mention of thunder. Low level moisture will
increase markedly by Friday morning with the warm front which
may produce another round of low clouds and fog...most notably
near the coast.

These low clouds as well as thicker clouds above will inhibit
development of instability on Friday. It is hard to find
guidance with much more than a thin ribbon of SBCAPE with the
cold front or pre-frontal trough. That said, any SBCAPE over
1000 J/kg will be problematic given the ample deep layer shear
expected over inland areas on Friday. The combination of low
LCLs, surface triggers and the shear bear close watch on Friday.

However, guidance today has shifted the threat towards heavy
rainfall Friday night as the front stalls and deep moisture
advects northeastward along the stalled boundary. This scenario,
promoted most notably by ECMWF, involves the northern stream
shortwave phasing with moisture drifting northward from a
disturbance currently in Florida. This involves a more amplified
upper trough to draw moisture northward. While most of the
tropical moisture pass well east of the area, PWs still surge
towards 1.5 inches for Downeast by Friday evening and we now
expect around an inch of rainfall Friday afternoon into Saturday
morning. WPC maintains a marginal risk in the ERO.

The stalled front also resulted a significant increase in PoPs
across Downeast on Saturday with lingering rain and clouds.
Further north, the cooler air behind the front will be in place
with highs falling short of 70F for Saturday high temps.
&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The long term is dominated by high pressure and initially
pleasant temperatures in the 70s. That changes by Monday as an
anomalously powerful upper level dome of high pressure builds
next week. Strong subsidence and warming will push temperatures
into 80s by Monday and into the 90s by Wednesday. These
temperatures combined with dew points climbing well into the
upper 60s by Wednesday will create oppressively warm conditions
that may necessitate a heat advisory.

Odds of a weak northern stream cold front clipping into the
area increase by Wednesday with the risk of thunderstorms, but
in general, the upper ridge looks like it will remain in place
through the week.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: Aroostook Terminals...Mainly VFR for tonight and
Thursday. For tonight, possible MVFR/IFR cig/vsby in late night
to early morning patchy fog. Light SW winds. For Thursday, SW
winds 5-10 kts.

Downeast Terminals...VFR early tonight for BGR, then IFR/LIFR
around midnight through the rest of the night in patchy fog.
IFR/LIFR all tonight for BHB in patchy fog. For Thursday, VFR
conditions. Light SW winds tonight. For Thursday, SW winds 5-10
kts.


SHORT TERM:
Thursday night...IFR likely to develop at BHB and BGR in the
evening. Sites further inland stand a chance of developing IFR
cigs by late night. South winds 10 to 15 kt.  LLWS likely.

Friday...IFR cigs expected in the morning. Chance of afternoon
thunderstorms. South winds 10 to 15 kt...becoming southwest in
the afternoon.

Friday night...IFR most of the night towards BGR and BHB and
coastal sites with embedded thunderstorms. Becoming VFR in the
evening north of GNR and HUL.

Saturday into Monday...VFR. North winds 10 to 15 kt Saturday.
Light winds Sunday into Monday.

&&

.MARINE...
NEAR TERM: Winds and seas will remain below SCA conditions
tonight and Thursday.


SHORT TERM:
Fog is likely Thursday night into Saturday morning. Densest fog
will probably be Friday night. Thunderstorms possible Friday
night. Otherwise adjusted guidance down for stability over the
cold waters. South winds Thursday night into Friday night will
become northerly for the weekend. Seas may approach around 5
feet on Friday and Friday night.

&&

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

&&

$$


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