Ellsworth, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

021
FXUS61 KCAR 201216
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
816 AM EDT Sun Jul 20 2025

.SYNOPSIS...
A cold front will cross the region later today as a weak low
tracks across the Gulf of Maine. High pressure will build in
from the northwest Sunday night into Monday, crest over the area
Tuesday, then continue south of the region on Wednesday. A cold
front will approach the area Thursday.

&&

.NEAR TERM /THROUGH MONDAY/...
815 am update...
Updated forecast for current position of showers over central
areas. This is in response to H3 speed max moving thru the Gaspe
Peninsula. Have increased pops in response to categorical for
the next hour until rain moves into New Brunswick. However, will
keep pops at high likely until next speed max rotates thru late
morning. Closest lightning strikes over nrn NH with convective
cells beginning to show themselves just northwest of Bangor at
this time. Lightningcast showing 30 probs for lightning to
develop in the next hour with an isolated strike now showing up
near Rangeley. Will retain mention of isolated tstms over
central areas, including Bangor over the next several hours
before becoming more widespread. Have retained locally heavy
rainfall as airmass remains juicy over Downeast. Still thinking
marine layer will limit severe storms but cannot rule out gusty
winds with any storms that may develop this afternoon. No other
chgs needed at this time.

Previous Discussion...
Today...Expecting increasingly potent 500mb shortwave to slide
east from Ontario into Quebec and nearing the Champlain Valley
of Vermont today. At the same time a cold front is pushing SE
ahead of the shortwave and weak cyclogenesis is taking place
over New York state in response to increasing upper level
divergence with the jet streak nearing New England. Warm moist
air will advect northward as a warm front pushes towards the
Downeast Coast over the Gulf of Maine. Increasing surface lift
over the state will result in scattered to numerous showers
across the area. Elevated instability noted by MUCAPEs
400-700j/kg across the Northern 1/2 of the CWA may result in
isolated to scattered thunderstorms but lack of instability will
keep thunder chances low. Increasing S-SSW winds along the
Downeast coast will push the Marine layer inland across Route 1
and will make a run towards Route 9 between Bangor and Calais.

It is this seabreeze boundary that becomes interesting zone
later today based on the hi-res cams. HRRR, RRFS, HRDPS and to
lesser extent 3km NAM are picking up on 500-1250j/kg of SBCAPE
developing near and just north of the seabreeze boundary.
Historically these boundaries have produced enough surface
convergence when combined with other parameters to produce a few
robust thunderstorms. Although south of the boundary hi-res
models are significantly struggling to understand surface based
CAPE is very hard to be produced when the wind is off a 50-55F
Gulf of Maine waters. The boundary will likely become the focus
for the potential of stronger storms that may produce gusty
winds. Lapse rates are marginal around 7C/km low and 6C/km mid
level but there will be increasing shear. Shear is expected to
reach 25-35kt low level and deep later 40-50kt and is even
giving supercell composite values 2-2.5 thanks to 150-200m2s2
helicity suggesting a few stronger rotating updrafts. SPCs new
D1 outlook seems decent minus the shoreline and coastal waters
with the best chance of potentially a stronger storm being just
along or north of the seabreeze boundary.

The other concern today will be heavy rainfall in any convection
that develops across the Central Highlands southward to the
seabreeze boundary. Numerous showers will likely produce
widespread 0.5-1.25 inch of rain in these areas. However, given
in cloud warm cloud processes will increase to 10-10.5kft today
as PWATs increase to near +2 sigma the bigger threat is heavy
rainfall. Thankfully, these areas have been rather dry over the
last 14 days so flash flood guidance is 2-2.5 inch in 1 hour and
2.5-3 inches in 3 hours. Given this the WPC ERO for today seems
to be a good fit with marginal risk of flash flooding. Any
concerns will be with small creeks, streams and urban poor
drainage areas. At this point with not a significantly
widespread threat will not be hoisting any headlines, will
handle with short fused advisories if needed.

Across the north today generally less instability means
scattered to widespread showers and just a small chance of a
thunderstorm or two. Today`s highs in to the low 70s areawide
except upper 60s along the shoreline. Tonight into tomorrow the
cold front swings east into New Brunswick with 500mb trof
remaining overhead into tomorrow. This will result in a cu field
developing as the sun comes up. Monday will be a breezy NW wind
gusting up to 20mph and cannot rule out a few isolated showers
north and perhaps a thunderstorm given a cool pocket aloft.
Highs top out in the mid 60s north but with the downslope off
the Longfellows expect upper 60s to low 70s for the Central
Highlands to Downeast coast including Bangor.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
High pressure building in from the west will bring a mostly clear
and very cool night Monday night with lows from the mid 40s
northwest to the low 50s Downeast. This will be followed by a mostly
sunny and dry days on Tuesday as the surface high crests nearby to
the southwest. The long range forecast models are showing a very
weak upper level disturbance moving in and crossing the area Tuesday
night. This may bring some patchy cloudiness overnight. Otherwise,
Tuesday night will be another dry and cool night with some 40s
across the northwest and low to mid 50s elsewhere. High pressure
will slide south of the area Wednesday allowing a return
southwesterly flow to pick up behind the high. This will usher in
some warmer air with highs Wednesday reaching seasonable norms in
the upper 70s over the area. Some moisture advecting back into the
region in the mid and upper levels may bring increasing clouds
Wednesday afternoon, especially across the north.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
High pressure will continue to slide south of the area Wednesday
night as a return southwesterly flow continues over the area. The
breeze and increased cloudiness will result in a much warmer night
than the nights earlier in the week with lows within a few degrees
of 60. A weak cold front will approach on Thursday bringing a mostly
cloudy day with chances for some showers or thunderstorms over
mainly northwesterly areas mainly during the afternoon. The front
will push into the area Thursday evenings. Surface convergence
working with cooler air advecting in aloft will continue to produce
showers and thunderstorms. Long range models show the potential for
some bands of heavy rainfall with the lowering heights sustaining
instability well into the evening. Showers and thunderstorms will
diminish later Thursday night. The front will push offshore Friday
morning as weak high pressure follows with partial clearing. Upper
level troughiness over far Eastern Canada will begin to slide east
on Saturday as longwave upper ridging in the northern branch starts
to build in. This should bring plenty of sunshine with seasonably
warm conditions on Saturday.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: Northern Terms...VFR cigs becoming MVFR today. -SHRA
likely and cannot rule out VCTS but probability is low. S-SW
winds 5-15kt shifting W-NW this evening. Tonight, low end VFR
cigs with VCSH. NW winds increasing 10-15kt. Tomorrow low end
VFR or high end MVFR cigs. VCSH possible with NW winds 10-15kt
gusting 20-25kt.

Southern Terms...IFR cigs this morning. Increasing -SHRA
coverage with PROB30 TSRA this afternoon. S winds 10-15kt.
Tonight, -SHRA will end and MVFR/IFR cigs expected to slowly
improve to MVFR/VFR overnight. Winds shift NW and increase
10-15kt. Tomorrow expect VFR cigs. NW winds 10-15kt with gusts
up to 20kt.

SHORT TERM:
Monday night into Tuesday...VFR. Light NW wind.

Tuesday night...VFR. Light NW wind becoming light and variable.

Wednesday...VFR. Light SW wind.

Wednesday night...VFR dropping to MVFR north, and possibly MVFR or
IFR over the south very late.

Thursday...MVFR or IFR, improving to VFR south and MVFR north. Light
SW wind.

&&

.MARINE...
NEAR TERM: Winds/seas below SCA criteria through Monday. Today S
winds gusting up to 20kt. Seas 2-4ft. Showers likely with
perhaps a thunderstorm within 10-15nm of the shore. Patchy fog
may also reduce vsby. Winds shift NW this evening. Vsby improves
overnight with winds gusting up to 20kt through tomorrow. Seas
subsiding to 1-2ft tomorrow. Sea surface water temperatures are
generally in the 50-55F range from the Downeast Coast out 25nm
and East to the Hague Line including Passamaquoddy and Penobscot
Bays.

SHORT TERM:
Wind and seas should remain below SCA through the coming week.
Dry air should allow good visibility Monday into Wednesday.
Humidity will return on likely resulting in a return of fog and
mist over the waters.

&&

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

&&

$$


Near Term...Buster/Sinko
Short Term...Bloomer
Long Term...Bloomer
Aviation...Buster/Sinko/Bloomer
Marine...Buster/Sinko/Bloomer