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712
FXUS61 KCAR 221625
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1225 PM EDT Sat Jun 22 2024

.SYNOPSIS...
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A stationary front will remain stalled near the coast this
afternoon. The front will lift north as a warm front tonight
into Sunday as low pressure approaches. Low pressure will cross
the area Sunday night into Monday followed by high pressure on
Tuesday. A cold front will approach on Wednesday.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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12:25 PM Update...Impulses continue to ride along a boundary
stalled near the coast. Showers associated with these impulses
have been confined to the Bangor region and Downeast. PoPs were
adjusted for the remainder of the day to reflect latest trends.

Previous Discussion...
A stationary from remains stalled along the coast dividing
relatively cooler and drier air to the north from warmer and
more humid air to the south. A band of light showers extends
along the frontal boundary near the coast. The front will remain
nearly stationary today. Moisture streaming east well ahead of
low pressure in the Upper Midwest will begin approaching along
the front today increasing chances of showers over southern
areas. The north will have a mix of sunshine and patchy high
clouds well north of the frontal boundary. Temperatures will
become warmer well north of the front due to more sunshine with
highs over the far north approaching 80. Clouds and showers will
keep southern areas cooler with highs only near 70 inland and
the 60s near the coast.

The stalled frontal boundary will begin to lift north as a warm
front tonight as the Midwestern low gets closer. Showers along
the front will evolve into a more widespread stratiform rain as
the front lifts north with the bulk of the rain beginning over
the highlands and western areas. Patchy light rain may begin to
reach the north early Sunday morning. Lows will be in the upper
50s across the region.
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&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
The stationary front, which lingers across Penobscot Bay into
the Gulf of Maine early Sunday morning, will begin to lift
northwards as a warm front through the day on Sunday, bringing a
plume of rain across the forecast area. This feature will be
enhanced by the left entrance region of a 250 mb jet streak of
around 120 to 130 kts. The parent low to the lifting warm front
will be tapped into moisture sourced from the eastern Gulf of
Mexico, feeding moisture into rainfall across the state of
Maine. The result is for PWATs to surge up into the 1.5 to 1.7
inch range by Sunday evening, which exceeds the 90 th percentile
for this time of the year across northern and eastern Maine.
Combined with a deep warm cloud layer of 11 to 12 kft, efficient
rain processes are the name of the game Sunday afternoon into
Sunday evening: a recipe for heavy rainfall, especially across
the northern half of the forecast area, which will be closer to
the synoptic forcing at this time. Some weak CAPE will also be
present, though the textbook long skinny CAPE typically seen
in heavy rainfall setups presents more as a short skinny CAPE
on forecast soundings, in part due to a strong surface inversion
with the overrunning setup and weak low to mid level lapse rates
within the warm sector. This presentation will also limit the
threat for thunder on Sunday, though isolated thunderstorms
remain possible.

With all these factors in place, total rainfall amounts with
this storm could easily exceed 1 to 1.25 inches, and locally
much more. One hindrance to this setup will be the mid level
flow, which will bring this rain into the area from the
southwest, over the Notre Dame and Longfellow Mountains, and
downsloping into the forecast area. Though rainfall could be
locally heavier on the upslope into the Longfellows in the North
Woods, the downslope may limit the full potential of this rain
event. Rain amounts will be less Downeast through the coast, as
the surface boundary clears the area which may receive a dry
slot as the low pivots through the area.

A cold front will clear through the area on Monday, pushing the
steadier rain offshore and lessening rain chances throughout the
forecast area. The GFS has been suggesting that the center of
the low will linger over the area, persisting rain showers
through Monday night, but this remains an outlier among
guidance. High pressure will quickly move in behind this area of
low pressure late on Monday, providing enough subsidence to
limit thunder threat.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
The forecast area should remain at the northern edge of a ridge
of high pressure Monday night through Tuesday night, keeping a
drier pattern in place. Another low pressure will approach the
area through the middle of the week, bringing the next threat
for rain to the region. Consensus across guidance is that a
robust cold front will gross the area late Wednesday through
Wednesday night. Ahead of the front, a pre-frontal trough is
possible, which could lead to thunderstorms Wednesday
afternoon. The cold front Wednesday night will reset the air
mass once more, with high pressure and seasonable temperatures
returning to the CWA through the end of the week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
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NEAR TERM: VFR conditions are expected across the north today
and tonight. Mainly MVFR BGR southward with some IFR at coastal
terminals through this evening. Conditions will deteriorate to
IFR BGR southward late tonight. Winds will be light southerly
today and very light southerly over the north and southeasterly
over the south tonight.

SHORT TERM:

Sun - Mon: IFR with areas of fog early, followed by scattered
rain showers at southern terminals and steady rain at northern
terminals. Winds SE at 5 to 10 kts Sun, shifting NE on Mon.
Strong LLJ around 2-3 kft could result in LLWS of 40 to 45 kts
at southern terminals through Sun night.

Mon night - Tues night: Improving conditions to VFR, with winds
N to NW at 5 to 10 kts.


Wed: VFR early, possibly becoming MVFR at northern terminals as
rain showers move in. Winds shifting S early Wed morning and
increasing to 5 to 15 kts.
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&&

.MARINE...
NEAR TERM: Wind and seas will be below SCA today and tonight.
Some fog is likely overnight as increasingly humid air lifts
back north over the waters.

SHORT TERM: Winds and seas will begin below SCA criteria on Sun,
though areas of fog could limit visibility. Winds aloft will
increase into Sun night, which could lead to surface gusts
approaching 25 kts Sun night into Mon morning. Seas will also
approach 6 to 7 ft with a system crossing the area into the day
on Mon. Conditions will improve Tues into Wed.

&&

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

&&

$$


Near Term...Bloomer/Clark
Short Term...AStrauser
Long Term...AStrauser
Aviation...Bloomer/Clark/AStrauser
Marine...Bloomer/Clark/AStrauser