597
FXUS61 KCAR 211630
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1230 PM EDT Tue May 21 2024

.SYNOPSIS...
High pressure will remain along the eastern seaboard through mid
week. An upper disturbance will cross the region this afternoon
into this evening. A strong cold front will cross the area
Thursday, followed by high pressure Friday into next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
12:30PM Update...Dew point boundary is pretty much overhead the
office with this update extending west/northwest to around
Clayton Lake where the winds have shifted somewhat. This
boundary will likely being the trigger point for thunderstorm
activity this afternoon. This boundary will continue to drift
south over the coming hours based on the continued trends in hi-
res cams. RAP Mesoanalysis shows SBCAPE building across the
area 500-1000j/kg with low-level lapse rates increasing
7.5-8.5C/km. Right now there remains some bulk shear of 30-40kt
across much of the Central Highlands northward. We are nearing
convective temperatures based on the morning soundings (82-84F).
925mb frontogenesis shows an area along the Longfellow Mtns
that will be likely the focus point of development over the
coming couple hours as we reach convective temp ahead of that
surface lift associated with the dew point boundary. Any
thunderstorms that do develop will have the potential to produce
small hail and gusty winds if they can become robust enough.
Will continue to monitor the trends with the best area of storms
from Moosehead Region to Baxter State Park to Southern
Aroostook County. No other major changes with this update...

previous discussion
Surface high stretching from Nova Scotia to the mid atlantic will
drift slowly east into the western atlantic today. Upper ridging
remains along the eastern seaboard. The main focus today remains
with regard to the approaching short wave/remnant MCV that will
continue to track eastward from the great lakes region and
toward northern New England. There is still some uncertainty
regarding the convective potential across the forecast area
today. Latest CAMs indicating that the most numerous convection
this afternoon may remain to our southwest across VT/NH into
southwest Maine. SPC continues to have a portion of our CWA
outlined in a marginal risk for severe today. This area is
mainly from just north of the Bangor region, to Houlton, and
then west through northern Somerset county. Thus continued to
mention isolated thunder with gusty winds/small hail. The
warmest temperatures this afternoon will be found to the north
of the Bangor region, where highs will top out around the 80
degree mark. A more of an onshore flow will keep Downeast
areas, especially the coast much cooler.

Tonight will be mainly cloudy with early evening isolated
thunderstorms diminishing to scattered showers and mainly
cloudy skies, Low clouds and fog will likley be an issue once
again for the coast and portions of Downeast. It will be another
mild night with lows only around 60 degrees away from the
coast.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Showers may be ongoing Wednesday morning as vort max passes thru.
Lingering boundary looks to be present as well from prior
convection. This boundary will tend to sag south during the day
with thunderstorms developing along it, mainly over central sxns
of the CWA as airmass destabilizes. Given cloud cover and very
minimal forcing expected, think this will be more on the order
of pulse convection in the afternoon. Temps acrs the north
likely to warm to near 80 once again with l/m 80s for interior
Downeast, cooler along the coast.

Occluded warm front lifts through Wednesday night with warm
advection showers increasing. Patchy fog expected over entire
region in warm and humid airmass. By Thursday morning expect
that front will be just to the west of the state in Quebec. Pops
increase overnight with front approaching.

Expect categorical to likely pops across the north Thursday
morning with patchy fog remaining across the area. Frontal
movement will determine chances for storms on Thursday. Latest
guidance remains in disagreement on how quickly front passes
with compromise appears to be from the Caribou area down toward
Bangor. Have continued mention of tstms in the afternoon but
strength to storms will be dependent on timing as well as how
much airmass can destabilize after patchy fog burns off. Any
thermal gradient left over from fog will also add instability
gradients from late morning and early afternoon into the mix.

Front looks to move through Thursday evening with lingering
showers expected early. As skies clear mins will drop back into
the 50s by Friday morning.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Zonal flow expected on Friday with upr s/wv zipping thru in the
flow leading to aftn and evng showers across the north. H5 ridge
builds in briefly behind aforementioned wave with mainly dry
weather expected on Saturday. Temps over the weekend will still
be above normal, mainly in the u60s and 70s.

Skinny sfc ridge looks to shift east rapidly late in the weekend
with occlusion bringing showers on Sunday and again on Monday.
Prior runs from any model did not show this solution but have
slowly introduced slight chc showers Sunday and Sunday night
with pops increasing thru the end of the extended.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: For BGR/BHB, expect IFR/LIFR in low cloud and patchy
fog through about 15Z, then VFR thereafter. VFR conditions
early this evening will give way to IFR/LIFR again tonight in
developing low cloud and patchy fog. S wind 5 to 15 kt through
tonight.

For the northern terminals, VFR is expected into tonight, but patchy
low clouds may develop early this morning vicinity KHUL/KPQI
with possible localized brief sub VFR conditions. Patchy fog
may also result in sub VFR conditions developing late tonight. S
to SW wind 5 to 10 kt through tonight.

Isolated thunderstorms are expected to develop this afternoon.
Forecast confidence in timing/placement of any terminal
getting a TSRA is low, thus will not include in the latest TAF
forecast. Amendments will likley be needed this afternoon to
address any convective activity if, and when, it develops.

SHORT TERM:
Wednesday...VFR with afternoon storms possible. Light SW winds.

Wednesday night...MVFR/IFR in patchy fog and showers late. Light
S winds.

Thursday...VFR tempo IFR in storms along a cold front in the
afternoon. Light S winds, SW 5-10kts in the afternoon.

Thursday night-Saturday...Mainly VFR with MVFR cigs across the
north Friday in light showers. W 5-10kts becoming NW 5-15kts
Saturday morning.

&&

.MARINE...
NEAR TERM: Winds/seas will remain below SCA levels through tonight.
Visibility will be reduced at times to 1 to 3 NM in patchy fog
this morning and again late tonight.

SHORT TERM: Winds and seas below small craft levels through
Saturday. Fog will reduce visibilities over the waters through
late Thursday night before front moves through.

&&

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

&&

$$


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