234
FXUS61 KCAR 061923
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
323 PM EDT Sat Jul 6 2024

.SYNOPSIS...
Weak low pressure will drag a cold front across the area
tonight. High pressure builds Sunday into Monday. A weak surface
boundary approaches from the north Tuesday with a cold front
crossing the area Wednesday night.
&&

.NEAR TERM /THROUGH SUNDAY/...
A weak and disorganized surface low will move across the area
tonight in concert with a weakening upper level shortwave. These
features will help provide enough lift to produce another round
of showers and thunderstorms this evening. Clearing to the
southwest of the forecast area this afternoon may just nose into
southern Piscataquis and Penobscot counties late this afternoon.
The persistent inversion and low clouds will remain elsewhere
in the CWA. The clearing may allow enough instabilty for heavy
thunderstorms to form...or at least move into the area from more
unstable areas upstream. Given the low FFG, juicy PWs nearing 2
inches, dew points in the lower 70s, and the history of heavy
rainfall in the past two days, another round of locally heavy
precipitation seems quite possible this evening. Training cells
along the line currently stretching from northern New Hampshire
towards Piscataquis County are another reason for concern. WPC
maintains a marginal risk in the ERO. Enough rainfall for
localized flash flooding is possible into this evening. The
primary area of concern is southern Piscataquis.

The other diminishing concern, if storms can organize in the
next few hours would be winds. Shear is quite favorable this
evening, but decent instability has been very slow to
materialize upstream of the area. Low LCLs and the shear present
a little worry for weak rotation. SPC has a marginal risk for
severe storms grazing the far southwestern portion of the
forecast area.

Otherwise, the main story remains low clouds, drizzle and fog
under the inversion for most of the forecast area. The fog will
be thickest near the coast and a Dense Fog Advisory will have to
be a consideration as we move into the evening.

For Sunday, a slightly drier west wind and drier mid/upper
levels will allow fog and stratus to burn off fairly quickly in
the morning. Most of the area will see some sunshine. Residual
850mb moisture remains for cumulus. This moisture and
instability will allow development of scattered afternoon
showers and isolated thunderstorms. The very dry air aloft will
likely limit coverage and duration of any activity. A weak upper
trough arriving later in the afternoon will help provide
cooling aloft.

The warm and humid air mass remains in place for Sunday. The
sunshine will propel highs well into the 80s with continued
unpleasant humidity levels. Dew points will remain in the mid to
upper 60s.
&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Weak ridging remains over the area Sunday night into the day on
Monday, with the forecast area situated in the right entrance
region of the upper level jet streak. Though this jet streak
will quickly propagate eastward, lessening the influence, enough
instability may exist along with diurnal heating on Monday to
develop a few isolated showers Monday afternoon. Otherwise, a
drier pattern in terms of precipitation to start the week. That
said, warm muggy air will remain in place, with forecast highs
on Monday reaching into the mid 80s while dewpoints remain in
the mid to upper 60s.

Monday night into Tuesday, another jet streak of around 120 kts
aloft will approach from the west, with the forecast area
entering the right exit region of this streak. Some 500 mb
vorticity will approach from the west during this time as well.
With southwest return flow wrapping around the exiting ridge of
high pressure, the next wave of rain showers begin to enter the
forecast area from the south and west, aided by orographic lift
into the Central Highlands late in the day on Tuesday. Warm and
muggy conditions will continue, with highs lifting into the
upper 80s to near 90 during the day on Tuesday and dewpoints
remaining in the mid 60s across the north and approaching 70
Downeast.
&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The next low pressure system is likely to cross through the area
Wednesday into Wednesday night, with full support from the upper
levels all the way down through the surface. Showers should move
in from the southwest as the low crosses the area, passing into
New Brunswick by late Wednesday night. There is some uncertainty
with just how much moisture will be available at this point,
with the GFS pointing towards the leading edge of Beryl moisture
moving in at this point, while the ECMWF continues to suggest
that the pattern will not be quite so amplified, and that the
moisture will be confined to the southern CONUS through the
middle of the week.

There seems to be good agreement that the moisture from Beryl
will reach the forecast area at some point through the end of
the week, and this will support a generally unsettled pattern
with more showers and storms through the second half of the
week. Temperatures may remain around or just above average for
this time of the year, with dewpoints remaining steady in the
60s to lower 70s due to the continued moisture advection.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: IFR to LIFR vis and cig persist through the night for
all sites. BHB will be near VLIFR most of the night.
Thunderstorms are possible this evening...mostly from GNR and
HUL southward, but not near BHB and the coast.

For Sunday, IFR/VLIFR fog and stratus will break up by mid-
morning for all sites and VFR follows by early afternoon for all
terminals. An isolated thunderstorm is possible north of HUL and
GNR.


SHORT TERM:

Sun night...IFR in low clouds/patchy fog. Winds light and
variable.

Mon...Improving towards VFR. Winds SW around 5 kts.

Mon night...Generally VFR, with brief IFR/LIFR possible in
patchy fog. Light SW winds.

Tues...VFR cigs, with showers moving in late from the SW. SW
winds 5 to 10 kts.

Tues night - Wed...MVFR with scattered rain showers. Light W
winds.

Wed night - Thurs...MVFR with lingering showers. Winds light
and variable.

&&

.MARINE...
NEAR TERM: Winds and seas will slowly diminish tonight into
Sunday. Although some gusts have reached over 20 kt today, do
not anticipate the need for a Small Craft Advisory. Fog remains
the greatest problem with little improvement expected through
tomorrow...except along the immediate coast by later Sunday
morning.

SHORT TERM: Winds and seas are expected to remain below small
craft advisory levels through the middle of the week.

&&

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

&&

$$


Near Term...MCW
Short Term...AStrauser
Long Term...AStrauser
Aviation...MCW/AStrauser
Marine...MCW/AStrauser