Area Forecast Discussion
Issued by NWS Caribou, ME

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845
FXUS61 KCAR 080928
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
528 AM EDT Tue Sep 8 2026

.WHAT HAS CHANGED...
- Updated aviation discussion.

- Increasing confidence for decoupling Tuesday night, which
  could result in frost in the north.

- Confidence continuing to increase in a soaking rain Wednesday
  night and in gusty winds Wednesday night and Thursday.

&&

.KEY MESSAGES...
1) Chilly overnight Tuesday night. Chance for frost in the
north.

2) Soaking rain is expected areawide Wednesday night, with gusty
winds Wednesday night and Thursday. Can`t rule out isolated
power outages during the day Thursday from the wind.

&&

.DISCUSSION...
KEY MESSAGE 1...Chilly overnight Tuesday night. Chance for
frost in the north.

KEY MESSAGE 1 DESCRIPTION...
Cool airmass moves over northern Maine Tuesday night. There is
a chance for atmospheric decoupling early in the night, as skies
clear out. This will help temperatures to drop into the 30s.
Potential for northern areas in Aroostook to drop into the low-
to-mid 30s, which will lead to some frost development. Frost
chances are going to be highly dependent on the timing of some
high level clouds moving in late Tuesday night into early
Wednesday morning. If the clouds move in earlier in the night,
temperatures will stabilize faster. If clouds move in slower,
then there is more time for the temperatures to drop with clear
skies. Currently, the set up looks more favorable for
decoupling, and thus colder temperatures.

The next chance of frost comes Friday night.

KEY MESSAGE 2...Soaking rain is expected areawide Wednesday night,
with gusty winds Wednesday night and Thursday. Can`t rule out
isolated power outages during the day Thursday from the wind.

KEY MESSAGE 2 DESCRIPTION...
Fairly strong system expected Wednesday night/Thursday. Surface
low pressure will be passing well to our north, with a potent
warm front Wednesday night followed by a cold front Thursday. A
few impressive things about this system include an unusually
strong upper level westerly jet stream, high precipitable water,
and unusually strong 850mb winds. These three parameters are
running above the 95th percentile for this time of year.

Rain: Rain looks to begin early Wednesday evening and taper off
around sunrise Thursday. The rain will be occasionally moderate,
and can`t rule out an embedded thunderstorm with some
instability aloft. We are looking at over 0.25 inch rain for
most areas, with a 50-75 percent chance of exceeding 0.50 inch.
Chances are only 20 percent or less of exceeding 1 inch though.
This won`t be enough rain for flooding concerns, but will help
with the dry conditions/drought. Could be a few showers
persisting during the day Thursday mainly in the north, but the
vast majority of the rain comes Wednesday night.

Wind: As mentioned before, we are looking at potent winds aloft,
most likely coming in the middle of the night Wednesday night
from the south, and again during the day Thursday from the west.
The winds aloft will be the strongest Wednesday night with up
to about 55 kt at 850mb, but it is very unlikely that these
winds will reach the ground due to stable low levels that are
decoupled from the atmosphere aloft. More realistically, we are
looking at gusts as high as about 30 mph from the south
Wednesday night. During the day Thursday, though the winds aloft
aren`t quite as strong, the winds have a much better shot at
mixing down to the ground thanks to cold advection aloft with
steeper lapse rates, plus the fact that it`s daytime. Gusts to
about 35 mph from the west appear likely Thursday, and with wet
soils after Wednesday night`s rain plus leaves on the trees,
there could be very isolated tree damage/isolated power outages.
It remains breezy Thursday night/Friday, though not quite as
much as Thursday.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
Today...VFR, except intermittent MVFR GNR until about 13z.
Light showers possible before 14z BGR/BHB. NW winds 10-15kts
with gusts up to 20-25 kts.

Tuesday night-Wednesday...VFR overnight into the morning,
becoming MVFR/IFR late Wednesday evening as rain moves in from
the west. Light winds Tuesday night, becoming S winds 5-15 kts
on Wednesday, with gusts 20-25 kts possible.

Wednesday Night...MVFR/IFR with rain. S wind around 15 kts with
gusts to 25 kts, and likely LLWS with much strong winds aloft.

Thursday...Mainly VFR, with a chance of MVFR north in the
morning. Windy with W winds 15-20 kts with gusts to 30 kts.

Thursday Night and Friday...VFR with W winds 10-20 kts, gusting
25-30 kts during the day Friday.

Friday Night and Saturday...VFR with light winds.

&&

.MARINE...
Conditions below Small Craft Advisory levels today through
Wednesday. Seas generally 2-4 ft. Isolated showers possible
early this morning. W winds this morning, shifting NW this
afternoon. Winds shift NE Tuesday night, and become S on
Wednesday.

S/SW winds peak late Wednesday night, with about a 40 percent
chance of gales within 25 NM of the coast, and a 60 percent
chance of gales beyond 25 NM. Winds ease back below 25 kt by
late Thursday. Seas peak in the range of 5-9 ft late Wednesday
night into Thursday morning and then gradually subside. Winds
gradually shift to the NW for Friday and become variable and
light Saturday.

&&

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

&&

$$

DISCUSSION...ASB/TF
AVIATION...ASB/TF