466
FXUS61 KCAR 170801
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
401 AM EDT Tue Jun 17 2025

.SYNOPSIS...
High pressure continues to slide south of Nova Scotia today.
Low pressure will then pass northwest of the area Wednesday and
again on Thursday. A cold front will cross the area Thursday
night. A large area of high pressure will set up across the
Eastern seaboard Friday into Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As the high moves eastward, instability has increased slightly,
and a few showers associated with a weak shortwave are making
their way across the north. These are expected to taper off this
morning. Meanwhile, the marine layer is building across
Downeast, as seen on satellite. Cloud bases are a little higher
than expected, so fog may be limited this morning, but the
potential for drizzle still exists, particularly along the
coast.

A brief break in the weather will occur this afternoon, but by
evening, showers will develop across the southwest and spread
northeastward across the region. Precipitation will not be
heavy, but it will be enough to make things damp as humidities
rise across the area as well. Developing clouds and showers will
put a damper on the high temperatures for all but the North
Woods and Crown of Maine, where highs will read the upper 70s to
low 80s. Elsewhere, highs are expected in the low to mid 70s.
Overnight lows will be much warmer than the past few nights, in
the mid to upper 50s across the whole region.



&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
Increasing moisture is expected on Wednesday as low pressure
over northern Quebec causes moisture to pool ahead of a cold
front. This front will weaken and stall before reaching Maine.
More cloud cover is expected, limiting high temperatures,
particularly across eastern areas where the marine layer will
persist most of or all of the day. Breaks in the cloud cover are
most likely across the North Woods, where a few spots could
approach 80 degrees. Surface heating over this area could also
lead to scattered thunderstorms, while other areas see scattered
showers. Fog and low stratus will build across the area
Wednesday night with lows generally in the lower 60s and
isolated to scattered showers and drizzle possible.

Another shortwave trough will approach the area late Thursday.
Models continue to struggle with the influence of vigorous
convection over the Great Lakes on the progress of the shortwave
and resulting shortwave features. There appears to be a general
bimodal solution with the CMC/GFS showing a weaker and more
elongated trough and positively tilted 500mb shortwave, while
the ECMWF/RRFS/ICON solutions show a more negatively tilted
500mb trough with a stronger surface low. Given the influence of
convection and the latter group of models being able to resolve
convection better than the former, the ECMWF/RRFS/ICON solution
is the more likely outcome. In this scenario a stronger cold
front provides more uniform lift, leading to a lengthy QLCS
oriented north to south from southern Quebec towards PA/NJ.
Differences in the timing and speed of the surface and upper
level features exists and will be critical for determining the
magnitude of damaging wind risk for western portions of the
forecast area. If the features slow, convection will arrive late
with less damaging wind threat as low levels stabilize with loss
of daytime heating. MLCAPE around 500-1000 j/kg is most likely,
focused over the North Woods. Strong winds aloft will favor wind
as the primary threat despite only marginal low level dew point
depressions. Thunderstorms may last into the evening with
decreasing intensity across the rest of northern Maine as the
cold front moves across the area. High temperatures Thursday
will generally be in the 70s, with low temperatures Thursday
night falling into the upper 50s to lower 60s with substantial
cloud cover and increasing winds with the front.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
For the same reasons mentioned in the short term discussion,
Friday will most likely be drier than indicated on the NBM with
stronger NW flow advecting in drier air from Canada. However, a
small chance of showers was maintained with some uncertainty in
the low strength as it moves northeast into the Maritimes. Wind
gusts were raised from the NBM with potential for gusts in
excess of 30 mph with daytime mixing Friday. Temperatures will
generally be cooler, except along the coast with the switch to
offshore flow.

A warm front will lift across the area this weekend with just a
slight chance of a shower and modest increase in cloud cover as
it passes. High temperatures Saturday are expected to be
similar to Friday, with temperatures reaching the upper 70s to
lower 80s on Sunday behind the warm front.

The first significant outbreak of unseasonably warm and humid
weather is looking more likely for the beginning of next week as
an anomalous ridge builds across central Ontario and the Great
Lakes and gradually shifts eastward. The CPC has issued a
moderate risk for extreme heat, with a high risk for western
portions of the area including Bangor. While the details are
still uncertain, the heat and humidity is likely to build on
Monday into Tuesday, with dew points eventually reaching into
the upper 60s to 70s and high temperatures in the upper 80s to
low 90s possible. The forecast area will be on the northern
margins of the ridge, leading to a chance of showers and
thunderstorms, some of which could produce very heavy rainfall.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
NEAR TERM:
Low clouds have developed across Downeast, however
bases are higher than expected and so far only
MVFR conditions are being observed. This may prevent further fog
from developing, so its possible that the earlier forecast may
have been too pessimistic for flight conditions. Clouds will
dissipate mid-morning and conditions during the day should be
VFR for all areas. However tonight, low cigs/vis are expected to
develop with the incoming showers. IFR/LIFR is likely Downeast,
with northern TAF sites becoming MVFR, then IFR by late morning.
Winds across the area will be S to SW, gusting to near 20 kts
similar to yesterday.

SHORT TERM:
Wednesday: IFR early with SHRA possible, becoming
MVFR. SW winds 5 to 10 kts, gusting to 20 kts during the day.
IFR/LIFR returns from south to north Wednesday night in FG and
low stratus.

Thursday: IFR/LIFR in the morning, becoming VFR with tempo
MVFR/IFR in the late afternoon and evening with SHRA and
potential for a TS at northern terminals. S winds 5 to 10 kts,
gusting to 20 kts or higher around any TS.

Friday: MVFR/VFR. W winds shifting N-NW 10 to 15 kts with gusts to 25-30 kts.

Saturday: All terminals improving to VFR. W-NW winds 5 to 10
kts.

&&

.MARINE...
NEAR TERM: Winds and seas expected to remain below SCA criteria
for the near term. Seas will be 2 to 3 feet. Possible marine fog
developing, with reductions in visibility to near 1/2 mile
expected.


SHORT TERM: Winds and seas will remain below advisory levels
through Thursday. Marginal advisory level winds (25 kts) and
seas (5 ft) are likely (60 percent chance) Thursday night into
Friday. Fog will reduce visibility Wednesday and Thursday and
may be dense. The predominant wave period will be around 5 to 7
seconds through Saturday.

&&

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

&&

$$


Near Term...LF
Short Term...MStrauser
Long Term...MStrauser
Aviation...LF/MStrauser
Marine...LF/MStrauser