688
FXUS61 KCAR 101853
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
253 PM EDT Sun Aug 10 2025

.SYNOPSIS...
The region will remain on the backside of high pressure anchored
well to the south and east of the area through Tuesday night. A
cold front approaches from the northwest on Wednesday, then
crosses the area Wednesday night and Thursday. High pressure
then builds down from Southeastern Canada behind the front through
Friday.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
Afternoon cu field across the Central Highlands thanks to
upslope lift of the Longfellow Mtns will dissipate with the
loss of daytime heating as the sun sets around 750PM this
evening. Tonight, the 500mb ridge will strengthen over the area
and likely reach 590dam by late tonight. The 850mb temperatures
will be increasing and expecting moisture to be transported
into the state raising the dew points overnight. Temperatures
tonight at the surface will struggle to cool off with mostly
clear but hazy skies. Expect lows in the mid 60s across the
northern 1/2 of the CWA and low 60s Downeast to Bangor region as
some decent raditional cooling will take place. Right along the
Downeast coast especially the Washington County coast the cold
Gulf of Maine and Bay of Fundy waters will knock temps back into
the 50s. Expecting patchy to areas of fog tonight with a
moistening boundary layer. Fog may become dense at times along
the Downeast coast overnight into the morning hours.

Tomorrow will be hazy, hot and humid with the 500mb ridge
increasing to 592dam overhead which may be in the top 5 record
for 500mb heights in August recorded at KCAR, which RAOB records
date back to 1948. 850mb temps are warming into the +19C to +20C
range with decent agreement in the hi-res and globals. Expecting
surface temperatures under mostly sunny skies to warm well into
the low 90s and even a few mid 90s from Dover-Fox to Lincoln to
Eastern Aroostook. Expecting potential daily records to fall
tomorrow at some locations, see the climate section below for
more details. Expecting a seabreeze to develop in the late
morning thanks to the large thermal gradient between land and
the 50-55F SSTs offshore. 80s along the shore and 70s on the
islands expected. Lowered dew points 1-3 degrees given the
ongoing very dry conditions and deep mixing up to 850-830mb
tomorrow. Either way heat index values 95-98F have required the
hoisting of a Heat Advisory for much of Northern Maine, Central
Highlands into Bangor Region and Interior Downeast.

Tomorrow night will remain muggy and take a long time to cool
off back into the mid to upper 60s except at the shoreline in
the 50s. Cannot rule out a few locations only bottoming out at
70F. Given the warm muggy prolonged night and lack of cooling
and given Heat Advisory will be needed for Tuesday opted to run
the Heat Advisory straight through into the short term period of
Tuesday. Once again fog will be patchy to areas with some dense
fog possible especially Downeast.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
The region remains under deep layered ridging Tuesday and
Tuesday night. The result will be continued hot and dry
conditions, with minimal cloud cover. Noting that the NBMs 50th
percentile was warmer than the NBM (as it often correctly is in
scenarios like this), blended in 2/3 NBM50 with 1/3 NBM for
highs Tuesday. Highs on Tuesday should be around 15-20 degrees
above normal, with record high temperatures possible at many
locations. With air temperatures in the mid to upper 90s across
most of the region, and heat indices progged a few degrees
higher, have gone ahead and issued a heat advisory through 00z
Wednesday. Lows Tuesday night should be around 5-10 degrees
above normal.

The axis of the deep layered ridge slides to the east on
Wednesday, allowing a northern stream shortwave rounding the
base of a closed low near Hudson Bay, to pass close enough to
bring isolated to scattered showers and thunderstorms to the
region, with the best chance across the North. Should see around
750-1500 J/kg of CAPE with bulk shear increasing to 15-25KT in
the afternoon. This could be sufficient to produce some locally
strong storms, with gusty winds possible. With precipitable
waters of around 1.5-1.75 inches coupled with a freezing level
around 12-14 kft suggest that there could be efficient warm rain
processes, resulting in locally heavy rainfall.

With suggestions that showers could move into far W areas by
around midday, went with NBM there for highs, and used blend of
2/3 NBM50 and 1/3 NBM elsewhere for highs. Temperatures should
be a few degrees lower on Wednesday with highs around 10-15
degrees above normal. The case for a heat advisory on Wednesday
currently appears marginal, and likely will be restricted to a
smaller area, with currently only the Bangor/Penobscot region
forecasted to have heat indices at/just above 95.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Northern stream toughing builds in Wednesday night-Thursday,
then exits to the east Thursday night. Ahead of it should see
more isolated to scattered showers and thunderstorms, possibly
into Thursday evening. Locally heavy rainfall remains a threat
with precipitable waters forecast around 1.5 inches and
freezing levels remaining high. It should then dry out from NW
to SE Thursday night.

Northern stream ridging builds in Friday-Friday night, then
exits to the east on Saturday, with associated subsidence
keeping things dry.

A northern stream shortwave trough crosses the area Saturday
night and Sunday, bringing some isolated to scattered showers,
along with possibly a rumble of thunder in the afternoon, mainly
across the North closest to the best dynamics.

Temperatures should remain above normal Wednesday night, return
to within a few degrees of normal on Thursday, then should be
below normal Thursday night-Friday night. Above normal
temperatures return for the upcoming weekend.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: Northern Terms...VFR tonight. Winds becoming light
and variable. BR/BCFG is possible at all sites with PQI having
highest confidence in reduced vsby. Tomorrow, expecting VFR
conditions. Light SW winds less than 10kt. Tomorrow night
BCFG/BR is possible again to reduce vsby with light and variable
winds.

Southern Terms...VFR this evening. BR/FG develops overnight
reducing vsby to IFR/LIFR at times. Winds light and variable.
Tomorrow IFR/LIFR early with BR/FG becoming VFR. SW winds 5-10kt
shifting S at BHB late morning. Tomorrow night expect VFR
becoming IFR/LIFR due to BR/FG once again. Winds light and
variable.

SHORT TERM:
Tuesday...VFR.

Tuesday night-Thursday evening...VFR, except for a brief period
of MVFR or IFR possible in any stronger convection. S-SW winds
G15-20KT possible Wednesday afternoon. NW winds G15-20KT
possible late Thursday.

Late Thursday night-Friday...VFR.

&&

.MARINE...
NEAR TERM: Winds/seas below SCA through tomorrow night. Fog will
reduce vsby at times tonight into tomorrow night.

SHORT TERM: A light pressure gradient will be over the waters,
except when it tightens briefly Wednesday night. As a result
winds should be 10 kt or less Tuesday-Friday, with the exception
of 15 kt or less Wednesday night. Seas should be 3 ft or less
due to the relatively light winds.

&&

.CLIMATE...
Record high temperatures are possible in some locations both
Monday and Tuesday.

Records Highs for Monday Aug 11:

Caribou: 92 in 2020, forecast high 94
Houlton: 91 in 2020, forecast high 93
Millinocket: 96 in 1944, forecast high 95
Bangor: 99 in 1944, forecast high 94

Record Highs for Tuesday Aug 12:

Caribou: 93 in 1944, forecast high 94
Houlton: 92 in 2020, forecast high 94
Millinocket: 94 in 1944, forecast high 96
Bangor: 100 in 1944, forecast high 95

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from 8 AM Monday to 8 PM EDT Tuesday for MEZ001-
     002-005-006-011-015>017-031-032.
     Beach Hazards Statement until 8 PM EDT this evening for MEZ029-
     030.
MARINE...None.

&&

$$


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