248
FXUS61 KCAR 220412
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1212 AM EDT Sun Sep 22 2024

.SYNOPSIS...
High pressure will build from eastern Canada through Sunday
night while low pressure in the open Atlantic drifts further
out to sea. High pressure will crest over the area Monday then
retreat into the Maritimes Tuesday and Wednesday.

&&

.NEAR TERM /THROUGH TODAY/...
1210 AM Update: Chgs this update was to mention a little more
in the way of clr skies ovr the far N for the next few hrs based
on latest sat imagery, then merge toward msly cldy skies toward
daybreak. Latest obsvd temps/dwpts were then used to update
fcst hrly values to unchgd posted lows at 6 am. Otherwise, the
rest of the near term fcst remains the same.

Previous Discussion: A Rex block remains over the area with
upper level high pressure over northern Quebec and low pressure
spinning in the open Atlantic southeast of Cape Cod. The trend
in the next 24 hours will be for the low to continue drifting
further southward while surface high pressure builds southward
from Labrador. This means continued dry weather and cool
temperatures.

The northeasterly flow induced by the pressure centers will
continue over the area through Sunday. That ensures plenty of
low level moisture for more cumulus/stratocu fields to develop
Sunday under the subsidence inversion. There will be less high
level cloud cover than today

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
High pressure remains the dominating feature for the short
term, with temperatures a little cooler than they have been, due
to the colder air mass that moved in from Canada last week.
Sunday night will be slightly cooler, since Monday will bring a
thicker layer of clouds, which should limit the radiational
cooling overnight. Overall this period will remain dry with
seasonable temperatures and light northeasterly winds.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
High pressure continues through Tuesday night, but by Wednesday
afternoon the pattern will begin to shift. The upper level
ridge will move eastward, allowing a trough to move in, bringing
precipitation across the area. Confidence is stronger that the
pattern will shift, however what will happen with the low/trough
that moves in is less certain. Model ensembles have a number of
different solutions, muddying the forecast for the end of the
week. This partially depends on how deep the upper level trough
becomes and whether it becomes negatively tilted, with a closed
upper level low forming somewhere over southern Canada or the
Midwest. There is potential for a surface low to develop over
the mid-Atlantic, moving northward and enhancing any precip that
falls Thursday and Friday. Deterministic runs of EC and
Canadian also show differences in whether the surface low
develops close to the coast and brings heavier bands of precip
onshore, or moves offshore more quickly. Given these differences
in the model runs, decided to keep pretty close to the previous
forecast for the Thursday through Saturday time period, keeping
precip over Maine longer than the NBM would indicate.
Temperatures will remain seasonable through the period.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: Variable conditions with any patchy fog overnight
through early Sunday across mostly northern areas. Occasional
MVFR ceilings also possible overnight into Sunday morning across
the forecast area. Otherwise, VFR overnight through Sunday.
East/northeast winds 5 to 10 knots overnight through Sunday.

SHORT TERM:
Sunday night through Tuesday...VFR with light northeasterly
winds becoming southerly.

Tuesday night through Thursday...MVFR developing with -SHRA.
Light E to SE winds.

&&

.MARINE...
NEAR TERM: A Small Craft Advisory remains in effect for much of
the waters, with the exception of the intra-coastal waters,
overnight through noon Sunday.

SHORT TERM: Winds remaining below 25kts for the duration. Seas
will be 1 to 3 feet through Thursday evening. The next
possibility for higher seas developing will be late Thursday
night with the movement of the surface low.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ050-051.

&&

$$


Near Term...VJN
Short Term...LF
Long Term...LF
Aviation...VJN/LF
Marine...VJN/LF