Bangor, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

293
FXUS61 KCAR 211919 CCA
AFDCAR

Area Forecast Discussion...CORRECTED
National Weather Service Caribou ME
319 PM EDT Sat Jun 21 2025

.SYNOPSIS...
A weather disturbance will approach from the west tonight and cross
the region early Sunday morning. A warm upper ridge of high pressure
will build across the area Sunday into early next week. A cold
front will move across the area Tuesday night, followed by high
pressure on Wednesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Main story in the Near Term period will be a decaying
mesoscale convective system (MCS) approaching early Sunday morning.
Skies remain mostly clear late this afternoon, then clouds increase
tonight ahead of the system. Most guidance tracks the center over
the Crown of Maine. This will bring rain showers to most of the area
beginning around sunrise Sunday morning. High-resolution models show
the strongest instability remaining southwest of the area. This will
likely preclude any severe thunderstorms. However, there will be
enough elevated instability for some embedded thunderstorms with the
MCS. With PWATS approaching 1.80 inches and a strong low level jet,
heavy downpours are a threat with any thunderstorms. Flash
flood guidance is lower than average due to recent rainfall.
Thus, isolated flash flooding is possible in heavier
thunderstorms. There is still some uncertainty with exact
rainfall amounts. This is because convection to the southwest
could siphon off moisture from Northern and Eastern Maine.
Showers will become less numerous in the afternoon as the MCC
quickly moves off to the east-southeast. However, still expect
lingering showers through the afternoon.

High temperatures on Sunday will vary significantly across the area.
With warm air advection and some afternoon clearing, highs will
likely reach the lower to mid 80s in the Penobscot and Piscatquis
River valleys.  Highs will remain in the 70s further north and east
due to cloud cover and showers hanging on longer. Coolest highs will
be in northeastern Aroostook County, where it will be a struggle to
reach 70 degrees. Humidity will increase area-wide Sunday, as dew
points climb into the 60s in the afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
High pressure builds across the area Sunday night as a broad
upper level ridge also builds northward over the area. Light
winds, mostly clear skies, and increasing moisture will favor
patchy fog, particularly across the river valleys and near the
coast. Low temperatures are expected to be seasonable in the
50s. Heat and humidity begins to build on Monday as dew points
climb into the 60s and temperatures into the 80s. An isolated
shower or thunderstorm is possible across Northern Maine, but
most areas remain dry as rising heights and sinking motion
suppresses the majority of convection. Monday night will be
unseasonably mild with lows around 70 across the north and in
the 60s for most other locations.

Dangerously hot and humid conditions peak on Tuesday as 590dam 500mb
heights reach the southwestern portion of the area. A very
shallow inversion will quickly mix out with rapid warming during
the morning hours. Moisture pooling ahead of a front over
Quebec will cause dew points to reach the 70s as temperatures
climb into the upper 80s and 90s. An Extreme Heat Watch has been
issued for the Penobscot Valley, which is most likely to
experience heat indices of 105 or greater. Most other areas will
see advisory level heat indices of 95 to 104 degrees Tuesday
afternoon. Regardless, this will be much hotter and humid
compared to any day so far this year, so there is the potential
to not be well acclimated to the heat and underestimate its
impacts. There is a moderate to high likelihood of breaking the
daily record high temperature of 93 in Bangor, which was set in
1995.

In addition to the heat, strong to severe thunderstorms are
possible across the north Tuesday afternoon, particularly if the
ridge begins to erode and heights begin to fall before sunset.
An approaching cold front may act as a trigger with the air mass
ahead extremely moist, unstable, and moderately sheared. Winds
are primarily unidirectional out of the west, so damaging winds
and hail would be the primary threats. Models are not
particularly bullish on widespread convection, likely due to the
ridging supporting sinking motion and marginal mid level lapse
rates. However, favorable thermodynamics may overcome these
factors.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Lingering showers and possibly thunderstorms Tuesday night will
end with advection of much drier and cooler air providing
relief from the heat on Wednesday with mostly clear skies and
highs in the 70s across the north and lower 80s across the
south. Dew points will also be notably lower in the 40s across
the north and low to mid 50s south.

Significant timing differences exist, but in general guidance
shows a shortwave trough moving across James Bay into Quebec and
clipping the northern part of the forecast area late Thursday
into Friday. Increased shower chances are expected during this
time. Heat and humidity will likely continue to be suppressed
south of the area with this feature, leading to near average
temperatures for late June with highs in the lower to mid 70s
and lows in the upper 40s to 50s favored.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NEAR TERM:
Northern Terminals: VFR through most of the night tonight.
Conditions quickly deteriorate to IFR early Sunday AM with SHRA
to +SHRA. VCTS expected Sunday AM. Improvement to at least MVFR
Sunday PM with VCSH. LLWS from around sunrise Sunday through the
day. NW winds 5-15 kts, with gusts 20-25 kts late this PM.
Winds light and variable this evening. S winds 5-10 kts with
gusts to 20 kts late tonight into Sunday AM. Isolated higher
gusts possible in any TS.

Southern Terminals...VFR conditions through most of tonight.
Periods of MVFR or lower possible Sunday AM with -SHRA and VCTS.
Otherwise, VFR through the day Sunday. LLWS Sunday AM. LLWS
ending at BGR early PM, continuing through the day Downeast. NW
winds 5-15 kts, with gusts to 20 kts late this PM. Winds light
and variable this evening. S winds 5-15 kts with gusts to 20 kts
late tonight into Sunday AM. Isolated higher gusts possible in
any TS.


SHORT TERM:
Sunday night to Monday night: VFR during the day. IFR/LIFR
possible briefly with patchy fog Sunday night, mainly across
coastal and river valley sites such as BHB, PQI, and MLT,
shifting more to the coast for Monday night. Light and variable
winds Sunday night shifting SSW at 5-15 kts Monday.

Tuesday: VFR. WSW winds 5-10 kts gusting to 20 kts. Scattered
TSRA across northern terminals in the afternoon may produce
tempo IFR conditions and briefly stronger wind gusts.

Tuesday night to Wednesday night: VFR. NW winds 5-15 kts
gusting to 20 kts during the day, becoming light and variable
Wednesday night.

Thursday: VFR with scattered SHRA during the afternoon. W winds
5-15 kts.

&&

.MARINE...
NEAR TERM: Winds and seas will remain below Small Craft Advisory
criteria through tonight. Winds and seas build above SCA levels on
the outer waters early Sunday morning. A few wind gusts could reach
25 kts on the intra-coastal waters Sunday morning. However, not
enough confidence to issue an SCA there at this time. Rain showers
could reduce visibility on the waters at times Sunday. Isolated
thunderstorms possible over the waters Sunday morning.


SHORT TERM: Winds and seas decrease below advisory criteria
Sunday night and remain below criteria through the remainder of
the week. Fog will reduce visibility at times Monday night into
Tuesday as a very humid air mass settles over the area.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Extreme Heat Watch from Tuesday morning through Tuesday
     evening for MEZ011-015-016-031.
     Beach Hazards Statement until 8 PM EDT this evening for MEZ029-
     030.
MARINE...Small Craft Advisory from 7 AM to 8 PM EDT Sunday for ANZ050-
     051.

&&

$$


Near Term...Clark
Short Term...MStrauser
Long Term...Buster/MStrauser
Aviation...Clark/MStrauser
Marine...Clark/MStrauser