154
FXUS61 KCAR 261645
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1245 PM EDT Thu Jun 26 2025

.SYNOPSIS...
High pressure will remain across the region through early
Friday, then exit across the Maritimes late. Low pressure
approaches from the west Friday night and Saturday, crosses
Maine Saturday night, then exits across the Maritimes Sunday
and Sunday night. A weak warm front will cross the area on
Monday.
&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
Surface high pressure will remain ridged across the region
today. Aloft, a disturbance moving around an upper low centered
near Labrador will cross the region this afternoon. High/mid
level clouds of various thicknesses will accompany the
disturbance. High temperatures will range from the upper 60s to
around 70 north, to the lower to mid 70s Downeast. Have updated
to adjust for current conditions along with expected afternoon
temperatures and clouds.

Previous Discussion...
Today...
The clouds will be at fairly high levels, generally 15-20,000
ft, though western portions of the area from Greenville to
Bangor to Bar Harbor could briefly see clouds down to about
12,000 ft. Can`t rule out a light sprinkle, mainly in western
portions of the forecast area, but that`s about it and don`t
think it will be enough to wet the pavement. Light NW breeze,
except light S breeze near the coast in the afternoon from a sea
breeze.

Tonight...
Clouds decrease late afternoon into the evening from NW to SE,
leaving mostly clear skies tonight with just a few high clouds.
Another cool night, with light winds and good radiational
cooling, and lows in the 40s to low 50s. Readings will be
similar to Wednesday night over the north, and about 5 degrees F
cooler Downeast. Went cooler than NBM and most model guidance
for low temperatures.
&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Northern stream ridging builds across the area on Friday with
associated subsidence keeping things dry. There should be
though an increase in mainly high clouds by afternoon,
especially across western zones. Highs on Friday should be near
to slightly below normal.

The models differ in the timing of the onset of precipitation
Friday night. The ECMWF is most progressive, as it is most
progressive with a 700 mb northern stream shortwave, while other
models are much less progressive with the 700 mb shortwave. All
models show low level frontogenesis developing along an axis
from the central/southern Central Highlands southeastward into
Downeast Maine. Given the flow aloft, it makes sense given the
flow aloft that precipitation would be mainly concentrated in
the area with the frontogenesis. This aligns more with a non-
ECMWF solution, so leaned strongly towards this for pops. As a
result would expect most, if not all the rain Friday night to be
confined from the Central Highlands into Downeast Maine, with
limited, if any rainfall to the north. Lows Friday night should
be around 5 degrees below normal.

The aforementioned 700 mb shortwave does lift northward Saturday
followed by the 850 mb warm front lifting northeast through the
region Saturday night. This coupled with developing isentropic
lift should support a period of rain during this time frame.
Moderate, to possibly locally heavy rainfall should be focused
mainly along the 850 warm front/maximum of low level
frontogenesis/area of strongest isentropic lift, along with the
support of a 35-50KT low level jet, which overlap in this case
over the central/southern Central Highlands into Downeast Maine
for most of this time frame.

Highs Saturday should be around 10-20 degrees below normal
(largest departure over areas with the heaviest rainfall). Lows
Saturday night should be near to a few degrees below normal.

From Friday night-Saturday night around 1-1.5 inches of rain is
forecast from Central/Southern portions of the Central Highlands
down into Downeast Maine. Lesser amounts are expected S of a
St Zacharie to Katahdin to Danforth line, with less than 1/4 of
an inch possible across the Saint Johns Valley. With this
rainfall below FFG, and expected to occur over 12-24 hours, no
significant hydrologic issues are expected, however, the
ponding of water in roadways in low lying areas cannot be ruled
out from the Central Highlands into Downeast Maine.

Last, but not least, showalter indices do support a slight
chance of thunder along coastal Hancock late Saturday
afternoon/early Saturday evening.
&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Northern stream ridging builds in Sunday-Monday, then exits to
the east Monday night. Models agree that an exiting 500 mb
trough ahead of the shortwave could bring some mainly scattered
showers on Sunday, then suggest that Sunday night-Monday should
be mainly dry. However, all models do bring through some weak
shortwaves (non-coherently) in this time frame, so account for
this with slight chance pops. Depending on how quickly the
northern steam ridging exits, there could be a chance for some
showers across far western zones late Monday night.

The models then all build in a mean northern stream trough into
the northeast Tuesday-Wednesday. However they differ on the
timing and coherence of the individual shortwaves which do this.
The GFS and ECMWF suggest the bulk of the energy moves through
Tuesday into Tuesday night, while the CMC delays this push until
Wednesday. For now leaned more towards the GFS/ECMWF consistent
with most ensemble members. Noting a slowing trend with this
system from last night, so would not be surprised though, if
things ultimately worked slower than currently forecast, which
is why pops were limited to likely.

Temperatures should be below normal on Sunday, near normal
Sunday night and Monday, then above normal Monday night-
Wednesday.
&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR this afternoon through tonight. North/northwest
winds 5 to 10 knots, becoming variable this afternoon except
becoming south/southwest along the Downeast coast this
afternoon. Variable winds 5 to 10 knots tonight.

SHORT TERM:
Friday-Friday evening: VFR.

Late Friday night-Saturday night: MVFR or lower likely at
southern terminals and possible at northern terminals, with the
best chance for MVFR or lower at northern terminals Saturday
night. S-SW winds G15-20KT possible late Friday night-Saturday.
LLWS possible Saturday-Saturday night at southern terminals.

Sunday-Monday: Mainly VFR, with a chance for MVFR in any
showers. LLWS possible Sunday at southern terminals.
&&

.MARINE...
NEAR TERM: Winds/seas below small craft advisory levels this
afternoon through tonight.

SHORT TERM: A relaxed pressure gradient over the waters Friday
and Friday night will limit winds to 10 kt or less and seas to 2
ft or less. The pressure gradient increases on Saturday and
remains moderate into Saturday night, this should bring SCA
conditions to the coastal ocean waters during this time frame,
with conditions just below SCA levels on the intra-coastal
waters.

The pressure gradient relaxes again on Sunday, with winds
diminishing to 10 kt or less again, with this continuing through
Monday. Seas though on the coastal ocean waters could be slow
to subside due to long period swells, so SCA conditions could
linger over the coastal ocean waters on Sunday as a result.
&&

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

&&

$$


Near Term...Norcross/Foisy
Short Term...Maloit
Long Term...Maloit
Aviation...Norcross/Maloit
Marine...Norcross/Maloit