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000
FXUS61 KCAR 250213
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1013 PM EDT Sat Jul 24 2021

.SYNOPSIS...
High pressure will exit across the Maritimes tonight. A warm
front will approach the region Sunday and cross the area Sunday
night. A cold front crosses the state later Monday night into
Tuesday. High pressure builds Tuesday night and Wednesday. Low
pressure will track towards the area Thursday.

&&

.NEAR TERM /THROUGH SUNDAY/...
1015 pm update...
Showers are moving into nrn NYS ahead of wmfnt and upr lvl s/wv
with FA rmng in srly flow overnight. Cirrus is trying to
overspread the region tonight but dry airmass is eroding the ern
edge as it progresses into the region. Hv tweaked sky cover slightly
for the overnight hrs to take into account progression of clouds
per satellite imagery.

Prev discussion blo...
Tngt will be msly fair with mclr skies to begin with then
increasing cldnss ahead of a sfc occluded front and supporting
s/wv trof alf apchg from Wrn QB first ovr Wrn areas late tngt
then across Ern areas Sun morn. In addition, oceanic ST and
patchy fog will make a return to Downeast areas late tngt as
sfc-llvl winds become return S behind an ewrd departing sfc hi
movg toward the open W Atlc. The combo of a lgt return Srly
breeze and increase in cld cvr late tngt will keep ovrngt lows
sig milder than last ngt.

Sun, shwrs with the occluded front will move into Wrn areas in
the morn, then across the E durg the aftn. Models in the near
term indicate stretching and weakening frontal dynamics as the
front traverses from the QB border Sun morn to the NB border by
eve. Subsequently, the shwr band will be most solid in cvrg and
intense near the QB border, with band becoming broken and much
weaker by the tm it apchs the NB border. Fcst model CAPE`s
suggest that thunderstorms from tngt ovr Cntrl QB prov may
linger into Wrn ptns of our FA midday into aftn before
dissipating as the shwrs reach Ern areas. Subsequently, the
best rnfl potential of 0.25 to 0.35 inches will be near the QB
border by erly Sun Eve, with a tenth of an inch or less alg the
NB border. Hi temps Sun Aftn will be cooler than Tdy`s,
especially Wrn areas, due to cld cvr, shwrs, and S winds from
the Gulf of ME.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
The warm front is the focus of attention Sunday night with light
rain, drizzle and fog under a frontal inversion. Warmer and
moister air advects into the region through the night and will
cap lows in the lower 60s. The first shortwave with the warm
front weakens significantly by Sunday evening and precip amounts
will be light. However, a more vigorous shortwave arrives later
in the night with some relatively decent mid level lapse rates
for this region, increasing shear and elevated instability above
the inversion. Thunderstorms seem most likely north of the
Moosehead and Katahdin regions late Monday night into early
Tuesday morning. For Monday, a warm and humid air mass will be
in place with highs climbing into the upper 70s to lower 80s
after low clouds burn off in the morning. Dew points in the mid
60s will help provide fuel for afternoon
thunderstorms...especially in the southern half of the area
where dew points in the upper 60s are possible. There`s not a
good shortwave trigger like earlier in the morning, but some
fairly robust CAPE values and just enough shear could produce
isolated afternoon thunderstorms...most likely along a weak
boundary stretching from far southern Aroostook County towards
southern Penobscot County. It`s really dry aloft and am hard
pressed to foresee more than isolated storms. Have added mention
of gusty winds with thunderstorms in that area. Monday night
will be sticky with dew points generally remaining above 60F
ahead of a fairly strong cold front that will arrive in the far
western zones by late night. There is elevated instability all
night and can`t rule out another round of late night
thunderstorms with front. By the time daytime heating generates
any SBCAPE on Tuesday, the front will be moving into the
Downeast region for the afternoon. Have added thunderstorms for
this area for the afternoon into the evening. Shear is
particularly strong as the LFQ of a strong upper jet arrives.
The cold frontal boundary and approaching upper trough add
confidence to the thunderstorm potential.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The cold front will bring in cooler and less humid air for the
rest of the week. The outlook for Wednesday into early Thursday
has improved as a shortwave dives from the Great Lakes region
to a position well south of the forecast area during that
timeframe. As a result, have decreased PoPs, raised Wednesday`s
highs and decreased lows for Tuesday night as well as Wednesday
night. The period Thursday and Friday continues to provide an
entertaining variety of model solutions as the next northern
stream shortwave races into a persistent upper trough over the
region. The bottom line is that Thursday and Friday look
unsettled and cool with potential rainfall amounts up to an inch
or so. The unsettled and cool pattern continues into the
weekend with another shortwave arriving in the fast
northwesterly flow aloft by Saturday night or Sunday.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR over Downeast terminals tonight. BHB likely to
see IFR in cigs/vsbys move in after 08z and remain IFR cigs
through the end of the period. Light shra move in after 18z
Sunday. BGR will see SCT MVFR deck after 07z before dropping to
MVFR cigs after 16z in -shra and eventually IFR after 19z.

Northern terminals may see a SCT MVFR cig move in early
afternoon and then MVFR after 18z in -shra. KFVE likely to drop
to IFR after 19z with remainder of nrn terminals seeing SCT IFR
clds with low MVFR cig.

SHORT TERM: Sunday night into Monday morning...IFR to LIFR due
to fog, drizzle and low clouds. Thunderstorms possible north of
GNR and HUL later Sunday night.

Monday afternoon...VFR out of thunderstorms.

Monday night...Slight chance of thunderstorms with a cold front.
Potential for IFR cigs towards Eastport and Machias.

Tuesday...Chance of afternoon thunderstorms...otherwise VFR.

Tuesday night into Thursday...VFR.

&&

.MARINE...
NEAR TERM: Tranquil wind/wv conditions well below SCA thresholds
cont tngt, with S winds and seas gradually building durg the day
Sun, but still xpctd to remain below SCA thresholds. Oceanic
ST/fog will make a return ovr our waters beginning late tngt and
contg thru the day Sun. Kept close to blended wv model guidance
with fcst wv hts this ptn of the fcst. Wvs will be composed of
three spectral groups: A very short fetch 3 to 5 sec pd group
advcg from the S, an intermediate 7 to 8 sec pd group advcg
from the SSE, and an open Atlc background swell of 10 to 12 sec
pd group advcg from the SE.

SHORT TERM: Continue to adjust model winds down for Sunday night
due to stability and do not foresee the need for any advisories.
With the stability, fog will be an issue Sunday night until a
cold front sweeps it out Tuesday. Thunderstorms are possible
with the cold front later Tuesday.

&&

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

&&

$$

Near Term...Farrar/VJN
Short Term...MCW
Long Term...MCW
Aviation...Farrar/VJN/MCW
Marine...Farrar/VJN/MCW