982
FXUS61 KCAR 082247
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
647 PM EDT Sat Jun 8 2024

.SYNOPSIS...
Low pressure over east central Quebec tonight slowly tracks
east into the Canadian Maritimes Sunday, as a coastal low passes
to the south. The low over the Canadian Maritimes continues to
slowly move east Monday through Tuesday, bringing weak troughs
of low pressure through the region as it does so. Weak high
pressure then builds in Tuesday night and Wednesday, then slowly
slides to the east through Thursday, allowing a warm front to
lift to the north.

&&

.NEAR TERM /THROUGH SUNDAY/...
6:47PM Update...Scattered to numerous showers continue across
much of the CWA this evening with just a few lightning strikes
left. 500mb low continues to slowly drift east tonight to near
the Vermont/Quebec border with cooling air aloft. Best chance of
showers overnight will be from the Moosehead to Baxter regions
points northward while mainly patchy to areas of fog developing.
No major changes to the ongoing forecast...

Previous Discussion...
A broad area of low pressure over northern New England will
continue to slowly churn northeastward this evening into the
night tonight. Isolated to scattered thunderstorms of the early
evening are primarily driven by diurnal heating, and as such,
will begin to taper off as the sun sets tonight. With the center
of the low passing just north of the St. John Valley, scattered
rain showers remain possible across the north through the night
tonight, while the Downeast region may begin to clear out. That
said, the rain from earlier has increased low level moisture,
increasing the chance for areas of dense fog to develop,
potentially reducing visibility.

For the day on Sunday, the broad area of low pressure will
continue to influence the synoptic weather pattern, and diurnal
heating will once again provide enough lift to take advantage of
the instability and moisture across the region for another day
of scattered showers and storms. Forecast soundings indicate
slightly smaller CAPE profiles than was seen with the Saturday
storms, though the HREF does suggest up to 500 J/kg MUCAPE is
possible Sunday afternoon, limiting severe potential.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
The cutoff low tracks across northern Maine into New Brunswick
Sunday night. Should see showers with possibly some rumble
of thunder across the North in the evening, ahead of the low,
taper off as the circulation moves to the east. Other than
possibly a few strong storms with locally heavy rainfall early
in the evening over Eastern Aroostook, any precipitation which
falls Sunday night should not have any significant impact. Lows
Sunday night should be near normal.

The region remains in the residual trough from the departing and
weakening cutoff low Monday-Tuesday. The result will be mainly
diurnal showers with decreasing coverage and intensity from
Monday into Tuesday. Limited pops to chance on Monday and slight
chance on Tuesday and used areal coverage wording to reflect
this. While a rumble of thunder cannot be completely ruled out
MOnday and Tuesday, the chance of occurrence is too low to
reflect in the forecast at this time. Expect any diurnal
showers to become increasingly more of a miss than hit nature
during this time.

Highs Monday and Monday night should be near normal and highs
on Tuesday should be around 5 degrees above normal.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The region will continue to see diurnal convection Tuesday
night-Wednesday night as the residual troughing slowly
dissipates over the region.

A northern stream shortwave passes on Thursday bringing with it
a chance of showers and a slight chance of thunder, with the
best chance across the North - which is closest to the best
dynamics with this system.

There could be some lingering showers Thursday evening depending
on exactly how fast the northern stream shortwave exits,
otherwise it should be dry Thursday night in the wake of this
system.

The models then differ in the handling of the next northern
stream system, with the ECMWF and CMC fairly well clustered
along with most ensemble members, with a slower system than the
more progressive GFS. Given the overall tendency of the GFS to
be too progressive as a whole, favored a CMC/ECMWF blend Friday-
Saturday. As a result have highest pops late Friday/Friday
night along with a slight chance of thunder, when the associated
cold front is most likely too pass. There could be some residual
showers on Saturday with the arrival of the upper level cold
pool. It is too early to assess the severe potential with this
system, but if it ends up being a night time frontal passage,
that tends to suggest that severe weather is less likely due to
a lack of solar heating.

Temperatures are forecast to be near normal Tuesday night, then
above normal Wednesday-Saturday. The temperature forecast is of
below normal confidence Friday-Saturday given the uncertainty in
the timing of the system then.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: Showers and thunderstorms continue across all
terminals early this evening. Any moderate to heavy rain
showers could briefly bring vis and cigs down to LIFR.
Otherwise, SCT to BKN IFR to low end MVFR cigs continue across
Downeast terminals, while BKN IFR cigs continue for the most
part across northern terminals. Winds light and variable.

Overnight, Downeast terminals likely to improve towards VFR,
though patchy fog could bring the threat for IFR conditions at
coastal terminals/BHB. From HUL north, cigs will likely remain
IFR with lingering SHRA, though the lightning threat will
diminish overnight. Winds SW around 5 to 10 kts.

On Sunday, ceilings may briefly improve towards VFR through the
morning, but another round of showers ant thunderstorms will
lead to deteriorating conditions falling to low end MVFR to IFR.
A return of lightning is possible to all non-coastal terminals
Sunday afternoon. Winds SW around 5 to 10 kts.

SHORT TERM:
Sunday Night/Monday morning...MVFR or lower possible.

Monday afternoon-Wednesday...VFR, except for brief period of
MVFR possible in any stronger showers in the afternoon and MVFR
or lower possible in patchy fog late at night/early in the
morning.

Wednesday night...VFR.

Thursday...VFR, except for brief period of MVFR possible in any
stronger convection. SW winds G15-20KT possible.

&&

.MARINE...
NEAR TERM: Winds and seas should remain below small craft
advisory levels through tonight and Sunday, though a few brief
gusts to 25 kts are possible in any rain showers early this
evening and again late Sunday afternoon. Patchy fog overnight
tonight could reduce visibility below 1 SM.

SHORT TERM: A light to moderate pressure gradient over the
waters Sunday night and Monday should allow for winds up to 15
kt along with some gusts to around 20 kt. Seas up to 4 ft are
possible.

The pressure gradient relaxes and should be light Monday night-
Thursday, limiting winds to 10 kt or less over the waters. Seas
should be 3 ft or less until possibly Thursday when a building
S-SW swell could increase seas to up to 3-4 ft on the waters.

&&

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

&&

$$


Near Term...AStrauser/Sinko
Short Term...Maloit
Long Term...Maloit
Aviation...AStrauser/Sinko/Maloit
Marine...AStrauser/Sinko/Maloit