509
FXUS61 KCAR 041014
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
614 AM EDT Wed Jun 4 2025

.SYNOPSIS...
High pressure will remain south of the area today and tonight. A
cold front will approach on Thursday, cross much of the area
Thursday afternoon and then stall near the Downeast coast
Thursday night into Friday. Low pressure will cross the area
Saturday and continue into the Maritimes on Sunday as high
pressure returns.

&&

.NEAR TERM /THROUGH TONIGHT/...
6:10 AM Update...The sky is mostly clear but hazy with forest
fire smoke spreading overhead aloft. A band of high clouds
associated with an upper level warm front is pushing southeast
across the Downeast region. Some additional high cloudiness will
spread in later today. Adjusted temps down early this morning
with the high clouds and haze delaying heating a bit. Otherwise,
forecast remains on track.

Previous discussion...
High pressure south of the area combined with upper level
ridging will bring a very warm and sunny day today with a light
southerly breeze. Satellite imagery from Tuesday showed some
forest fire smoke from the Western Canada wildfires advancing
behind an upper level warm front which crossed the area
late Tuesday night. This smoke will bring a hazy sky today.
Intially, the smoke will be mostly just aloft at altitudes
between 6K and 10K ft. However, as the mixing layer reaches
near or just above 6K ft during the mid to late afternoon
today, some of that smoke may mix down to the surface causing
some hazy reduction in visibility. Highs will be in the low to
mid 80s. An air quality alert remains up for Southern Hancock
County. However, this is primarily for high ozone levels.

Tonight will be clear and warm with an orangish waxing gibbous
moon as some smoke remains over the area. Downeast will be
coolest under more tranquil air with lows near or below 50 while
the northwest, with a southwesterly breeze ahead of a cold
front, will have lows near or just above 60.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
..Scattered Strong Thunderstorms Possible Thursday..

Threats: Gusty Winds, Small Hail, Heavy Rain and Deadly Cloud
to Ground Lightning.
Timing: 12PM - 8PM Thursday
Confidence: Moderate to High

..More Details..

Thursday AM expecting much of the smoke aloft to work out of the
area as the 500mb ridge axis works slightly east over the Gulf
of Maine. Temperatures will be in the upper 50s to low 60s
across the north from Moosehead to St. John Valley. Mid 50s for
the Central Highlands and Bangor region and with a more
southerly wind upper 40s for the Downeast. Morning fog in a
steep moist low level inversion Downeast will slowly mix out
during the morning.

Thursday by midday a weakening cold front will be approaching
the Maine/Quebec border. Cu clouds will develop from NW to SE
across the area in response to the approaching front as
convection gets underway. Temperatures will be reach highs by
midday with mid to upper 80s across the north, upper 80s to low
90s for the Central Highlands to Bangor region. 70s and 80s
Downeast but the sea breeze will strengthen and cool things
back into the 60s and 70s Downeast. The sea breeze front will
likely reach Route 9 from Bangor to Calais. Dew points will rise
into the 60s, likely reaching the upper 60s over central areas.
Both near surface and vertically integrated smoke densities
will decrease compared to Wednesday. Although some smoke will
linger, impacts to incoming solar radiation should be small.
Based on improved incoming solar radiation from lack of smoke,
solid agreement on 925mb temps 22-24C have opted to bump up
highs into the low 90s for portions of Penobscot, S. Piscataquis
into far southern Aroostook County. Thursday will turn out to
be Hazy, Hot and Humid for many locations.

The Storm Prediction Center has placed much of Maine in a D2
Marginal Risk for Severe Weather. Lets talk storms here...By
midday hi-res CAMs and global models showing solid
1000-1500j/kg of SBCAPE with even a ribbon of 1500-2000j/kg in
the Central Highlands to NE Aroostook. SBCAPE >750j/kg will be
present anywhere outside of the seabreeze influenced area. The
moisture pooling ahead of the front combined with increasingly
unstable airmass will result in cu building into stronger
convection. In classical New England Marginal Risk days we we
tend to be lacking one or two components, and this isn`t any
different with weaker shearing. Northern and Central areas will
start the mid afternoon with 20-30kts of effective shear
gradually increasing to 30-40kt by late afternoon. Models
continue to show weak mid-level lapse rates (6C/km) and dry air
in the mid to upper levels which means uncertainty on storm
strength is a real concern. Elevated DCAPEs, inverted "v"
signature soundings and some elevated dry air may be efficient
to enhanced downward vertical motions enhancing winds within
convection. However, many solutions continue to suggest the
potential for at least a few strong to severe thunderstorms
capable of producing hail and damaging winds north of the marine
layer.

Additionally, PWATs will increase to 1.4-1.7 inches across the
area which is 2-2.5 sigma for climate normals. Therefore, within
the convection heavy rainfall will also be a threat into the
evening as the SW-NE oriented boundary nearly aligns with the
storm motion, leading to the potential for some training. Heavy
rainfall processes are favored with deep warm cloud layers up
to 10-12kft AGL and storm motions being less than 20kt. Lastly,
given the above normal precipitation this Meteorological spring
the 1 and 3hr FFG is generally low across the area.
In addition the top 20 inches of the soil across the area is in
the 90th-99th percentile, so the grounds are soaked!

Given all of this opted to add enhanced wording for small hail,
gusty winds and heavy rain to the thunderstorm in the
forecast.Not a widespread outbreak of storms but this is the
first threat of storms this season. Given the warm weather, many
folks likely outside its important to dust off knowing what to
do if you are caught outside. When Thunder Roars Head Indoors.

Storms will end in the evening with the loss of daytime heating
but the front will slowly become quasi- stationary over the
Interior Downeast region. A few showers will continue through
the overnight but warm moist air south of this boundary will
likely result in fog forming Downeast. It will be one of the
most mild nights of the year so far with lows in the upper 50s
to lower 60s. By Friday the front will focus most convection
south of the area, but a few showers will remain possible,
especially over central and southern portions of the area with
lingering instability. Mostly cloudy skies are expected with
temperatures in the 70s to around 80.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Model guidance diverges significantly for this weekend, but
generally favors yet another unsettled and wet weekend, with the
GFS taking a robust multi low pressure area over the area,
while most other guidance takes a weaker low off the coast to
our south with differing speed. Regardless of the exact
solution, at least widespread showers are expected on Saturday,
with higher probabilities to the south given the favored non-
GFS solution.

Ridging will build east of the area early next week, but
troughing will persist west of the area over the Great Lakes.
This upper level pattern will favor a continuous stream of
moisture from the Gulf states, leading to showers and possibly
isolated thunderstorms, especially with daytime heating.
Seasonable to slightly above average temperatures are favored
into next week, with highs primarily in the 70s and lows in the
50s.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR conditions are expected today and tonight. Forest
fire smoke may reduce visibilities down to around 6 NM today
into tonight. Winds light southerly today and tonight.

SHORT TERM: Thu...AM IFR possible due to FG at BGR and BHB. VFR
cigs otherwise. Northern terms W-SW winds 5-15kt, southern terms
S-SSW winds 5-15kt. From 16z-00z brief MVFR/IFR cigs/vsby for
BGR and all northern terms. -SHRA likely with TSRA possible.
TSRA will have the potential to produce gusty winds, small hail,
heavy rain and numerous lightning strikes.

Thu night...FG may reduce vsby at southern terms. Otherwise
VCSH/-SHRA possible. Mainly VFR but potential for MVFR cigs at
northern terms. Winds shifting W-NW around 5kt from BGR
northward.

Fri...AM FG at BHB with possible IFR. Otherwise VFR cigs
elsewhere. VCSH/-SHRA from HUL southward through the afternoon.
N winds 5-10kt except SW 5-10kt at BHB.

Sat...VFR/MVFR cigs with potential for IFR. -SHRA likely. SE
winds 5-15kt.

Sun...VFR/MVFR cigs with possible -SHRA. NW winds 5-15kt.

&&

.MARINE...
NEAR TERM: Wind and seas will be below SCA today and tonight.
Humid air over the cooler waters may result in a bit of light
fog or mist through tonight.

SHORT TERM: Winds/seas below SCA conditions through Saturday
evening. Fog Thursday AM may result in reduced vsby, showers and
fog possible Thursday night. Patchy to areas of fog on Friday
then rain likely Saturday. Winds generally less than 15kt
through Saturday with seas 1-3ft. Sunday winds remain below SCA
but southerly swells at 8-9sec will build to 4-5ft across the
waters into Sunday night. Seas will gradually drop to 2-4ft by
Monday then 1-3ft by Tuesday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Air Quality Alert from 11 AM this morning to 11 PM EDT
     Thursday for MEZ029.
MARINE...None.

&&

$$


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