-- Discussion containing changed information from previous version are highlighted. --
530
FXUS61 KCAR 240502
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
102 AM EDT Fri May 24 2024

.SYNOPSIS...
A cold front will cross the area tonight, followed by a
secondary cold front on Friday. Weak high pressure builds in
Saturday and Saturday night, then slowly exits to the east
through Sunday night. A complex storm system slowly approaches
from the west Monday and Tuesday.

&&

.NEAR TERM /THROUGH TODAY/...
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1 am update...
Drier air has filtered into all but Downeast with locally dense
fog developing in this area. Will monitor for a short-lived
dense fog advisory. Quick update to ingest latest obs but no
major chgs needed.

Previous Discussion...
The large cold front associated with a large occlusion will
exit the region by tonight, making for a mostly clear night.
This evening will have decreasing and exiting showers and
thunderstorms with the front. The 925mb temps indicate that the
cooler airmass is further behind this front, more in conjunction
with the occlusion expected to move through on Friday. Temps
will be in the mid 50s across the area with light SW flow.

By Friday, another boundary will move through the region as the
occluded front swings across Quebec and into the state. For the
morning, clouds will gradually start to increase with the
boundary. The 925-850mb model temps show the temp gradient with
the cold airmass moving into the region by late morning. Thus
the warmest temps on the day will be at late morning, then
decrease throughout the rest of the day. By the afternoon,
showers will move across the north. Though models show
instability for the north, the lack of sunshine and cooler temps
could drive down the lift needed to produce thunderstorms.
Decided to remove isolated thunderstorms from the forecast.
However, cannot rule out a few rumbles after in the evening. WSW
winds will increase with the pressure and temp gradient, making
from a breezy day.
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&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
Northern stream ridging builds in Friday night and Saturday then
exits Saturday night. Associated should keep things dry and
also allow for minimal cloud cover Friday night and Saturday.
Mid and high clouds should begin to build in Saturday night,
especially after midnight. Lows Friday night should be a few
degrees above normal, highs on Saturday, and lows Saturday
night, should be near to a few degrees above normal.

The global models (except CMC-Global) suggest that a northern
stream shortwave should weaken the northern stream ridging
enough to allow for a northern stream shortwave to bring some
showers on Sunday. The high resolution models (plus CMC-Global)
suggest that the northern stream shortwave ridging should be
strong enough to shunt the bulk of the northern stream shortwave
to the north, so the region should have little or no
precipitation. Noting we are in a time of the year where
convective processes dominate, leaned towards the high
resolution models, which tend to handle convection better, so
limited pops to slight chance. Highs on Sunday should be around
5 degrees above normal.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Deep layered northern stream ridging builds in Sunday night.
Other than possibly some lingering showers from its preceding
shortwave, it should be dry.

Depending on how quickly the northern stream shortwave exits on
Monday will determine how much, if any, showers impact the
region on Monday. For now went with low end chance/high end
slight chance pops - mainly for the afternoon. If confidence
increases - it probably would be prudent to add in a chance for
some thunder Monday afternoon/evening.

A closed low tracks from SE Ontario into SW Quebec Monday night
and Tuesday. Should see showers increasing in coverage late
Monday night/Tuesday morning and continuing during the day. It
appears there should be sufficient surface to low level
instability to warrant at least a slight chance of thunder
during the day on Tuesday. There currently is too much
uncertainty in the details to offer a meaningful prediction on
how strong any thunderstorms might or might not be on Tuesday.

The global models all agree that a mean full latitude trough
builds into the eastern US Tuesday night-Thursday. They differ
though on the details of the timing of individual shortwave
troughs and embedded shortwaves. This makes going with more than
chance pops in this time frame difficult, as the timing of
exactly when it will or will not rain requires those factors to
be known. So for now, have gone with chance pops Tuesday night-
Thursday, but please note it WILL NOT rain the entire time
during this period, and more than likely not even half of this
time frame. Once there is a better sense of the time frame of
any precipitation, then some chances of thunder can be added to
the forecast as appropriate.

Temperatures should be near to slightly above normal Sunday
night and Monday, then above formal Monday night, near normal
Tuesday, above normal Tuesday night-Wednesday night, then near
normal on Thursday.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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NEAR TERM: VFR over northern Aroostook terminals with patchy fog
possible briefly at HUL initially. IFR/LIFR conditions at
Downeast terminals through approx 08-09z this morning before
improving to VFR.

SHORT TERM:
Friday night...VFR, except for possibly a period of MVFR at
northern terminals. NW winds G15-20KT possible.

Saturday-Sunday night...VFR. LLWS possible at southern terminals
Sunday.

Monday-Tuesday...MVFR or lower possible, with these conditions
potentially developing late Monday and then continuing into
Tuesday. SE winds G15-25KT and/or LLWS possible.
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&&

.MARINE...
NEAR TERM: Winds and seas will remain below SCA conditions for
tonight and Friday.

SHORT TERM: SCA conditions are possible on the coastal ocean
waters Friday evening, otherwise sub-SCA conditions should be
experienced on the waters Friday night-Monday night. SCA
conditions are possible again on the waters on Tuesday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
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ME...Beach Hazards Statement from 8 AM EDT this morning through
     this evening for MEZ029-030.
MARINE...None.
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&&

$$


Near Term...Buster/LaFlash
Short Term...Maloit
Long Term...Maloit
Aviation...Buster/LaFlash/Maloit
Marine...Buster/LaFlash/Maloit