-- Discussion containing changed information from previous version are highlighted. --
323
FXUS61 KCAR 201015
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
615 AM EDT Fri Sep 20 2024

.SYNOPSIS...
High pressure will build down from Eastern Canada today into the
weekend and crest over the area Monday. High pressure will be
over the Maritimes on Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
6:10 AM Update...The sky is beginning to clear over the far
north with a mostly cloudy sky elsewhere. Lowered temps a couple
degrees over far northeastern areas early this morning where
clearing has allowed for some cooling. Otherwise, the forecast
remains on track.

Previous discussion...
The sky will begin mostly cloudy over central and southern
areas this morning while partial clearing pushes into the north
beneath high pressure building down from Eastern Canada. As the
high continues to build down, the north will become mostly clear
today with partial clearing further south. Coastal areas may
remain mostly cloudy under the influence of low pressure well
off the coast. Today will be cooler than recent days with highs
only near 70 as cooler drier air pushes down from Canada.

Tonight will be clear to partly cloudy and cooler over the
north with lows in the low to mid 40s. Southern areas will be
mostly cloudy near the northern edge of the offshore storm.
Lows over the south will be in the mid 50s.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The blocking pattern that has prevailed across the FA ovr the
past week will be undergoing some evolution, with the cntr of
the upper high retreating further N ovr Can msly across Nrn QB
and Labrador. This allows low pres both at the sfc and alf to
reside ovr the open Atlc between Cape Cod and S of NS prov thru
Sat, with the most cldnss ovr the S hlf of the FA and sct shwrs
from the offshore rn shield perhaps grazing the Downeast coast
Sat Morn.

By Sat Eve, both the sfc and upper low will move further SE of
NS prov as sfc high pres from QB builds swrd, at least taking
any rn chcs swrd from the Downeast coast. Sky condition,
however, will remain uncertain, with NE llvl winds making it
uncertain how well the air below the subsidence invsn drys out,
meaning that there could be areas of thin SC cldnss. Temps will
slowly trend from abv normal closer to seasonal norms durg this
tm.

Outside of some patchy SC cldnss at tms, Sun and Mon look to be
fair and cooler, even a little below seasonal norms as sfc Can
high pres ridges swrd. Ordinarily, we would have to be
concerned about frost potential late Sun Ngt across Nrn vlys
with the sfc high directly ovr the FA after a cool prev day high
temps, but low dwpts and clrg from SC cld cvr are both uncertain,
so fcst lows ovr the N remain sig abv frzg with little frost
potential attm.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Mon Ngt at this tm does not look as cool as Sun Ngt as the llvl
core of the air mass moderates and llvl winds begin to return
from the S. Tue also looks fair with blended long range models
bringing increasing cldnss later Tue Ngt into Wed as llvl winds
increase from the S and SE to what could be the beginning of
the breakdown of the Ern Can-New Eng blocking pattern. Blended
long range guidance is in better agreement in holding off on
any PoPs abv slgt chc lvl until at least Wed Ngt, with PoPs now
well in the chc range for Thu as a low pres sys from the Midwest
apchs, perhaps bringing the first sig rnfl for our Rgn in a
couple of weeks.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR conditions are expected across the north today
and tonight. Southern areas will begin IFR to MVFR early this
morning then improve to VFR by mid morning. VFR conditions are
expected this afternoon into tonight. Light NE winds inland
today and tonight with a moderate NE wind along the coast.

SHORT TO LONG TERM: Sat - Sun Morn...all TAF sites msly VFR
with ocnl MVFR - low VFR clgs. Lgt to mdt ENE to NE winds, with
strongest winds at KBHB Sat.

Sun Aftn - Tue...all TAF sites low VFR clgs to unlmtd VFR with
Lgt and vrbl winds becmg S on Tue.

&&

.MARINE...
NEAR TERM: A SCA will be up for the offshore waters today and
tonight for east northeast winds gusting up to 30 kt. Winds will
gradually diminish tonight but some gusts to 25 kt will still
be possible over the offshore waters. Vsby will improve as
cooler and drier air push down from the north.

SHORT TO LONG TERM: SCA ENE wind gusts and accompanying seas
xpcted to cont thru Sat ovr the outer MZs and contg possibly
into Sun s sfc low pres ovr the open Atlc E of Cape Cod slowly
drifts SE. By later Sun into Sun Ngt, the pres grad ovr the
outer waters should weaken enough as the low conts to move
somewhat away for winds and seas to subside below SCA
thresholds and this should cont Mon into Tue. Kept close to
blended wv model guidance for fcst wv hts with wvs having two
components; a short fetch pd of 2 - 4 sec and an open swell pd
of 9 - 11 sec.

&&

.TIDES/COASTAL FLOODING...
High astronomical tides combined with a modest storm surge from
low pressure to the south will lead to minor tidal flooding at
the high tides around 1 PM Friday and 1PM Saturday. The
southernmost east facing islands and peninsulas will be most
subject to erosion, but most areas will see little wave action
due to the east-northeasterly wind direction relative to the
coastline. Areas further south along the Maine coast into
southern New England will have a greater coastal flooding threat
with more onshore flow.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ050-051.

&&

$$


Near Term...Bloomer
Short Term...VJN
Long Term...VJN
Aviation...Bloomer/VJN
Marine...Bloomer/VJN
Tides/Coastal Flooding...MStrauser/Bloomer