243
FXUS61 KCAR 051143
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
743 AM EDT Fri Jul 5 2024

.SYNOPSIS...
A weak cold front will stall across the area today. The front
then slowly lifts back north Saturday in the form of a warm
front. Another weak cold front will begin to cross the region
Sunday and move east of the region Monday. A surface trough is
expected to cross the area Tuesday.
&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
Have issued a Dense Fog Advisory for the Downeast coast through
9 AM with this update. Otherwise, have updated to adjust for
current conditions.

Previous Discussion...
A weak cold front will stall across northern Maine today into
tonight. Aloft, an upper level disturbance will cross the region
today into tonight. Expect scattered showers across the region
this morning. Scattered to numerous showers and thunderstorms
will then develop across much of the region this afternoon and
persist into the evening, most numerous across central and
northern areas closer to the stalled front and track of the
upper level disturbance. Precipitable water values increase to
between 1.50 and 1.75 inches this afternoon. Thus, expect any
thunderstorms this afternoon could produce locally heavy rain.
The marine layer will help provide more stable conditions along
the Downeast coast today where only scattered showers are
expected. Areas of low clouds and fog with the marine layer will
occur across Downeast areas this morning, locally dense. Patchy
fog is expected across northern areas this morning. The low
clouds and fog will retreat back toward the Downeast coast this
afternoon, though likely remain just offshore or near the
shoreline. High pressure centered north of Maine will build
toward northern portions of the forecast area overnight with
decreasing shower chances. Shower chances will persist Downeast
tonight. Low clouds and fog with the marine layer will move back
onshore across Downeast areas this evening, then expand
northward across the remainder of the forecast area overnight.
High temperatures today will range from the upper 70s to around
80 across much of the forecast area. Mid 60s to lower 70s are
expected along the Downeast coast with more persistent low
clouds and fog along with onshore winds. Low temperatures
tonight will range from the lower to mid 60s across northern
areas, with upper 50s to around 60 interior Downeast and mid to
upper 50s along the Downeast coast.
&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Saturday and Saturday Night...
Challenging precipitation forecast for Saturday into Saturday
evening in pinning down where and when the heavier shower
activity will be. Airmass will be very moist with precipitable
water values from 1.5 to 2 inches. There will be an approaching
upper level trough, but this trough is not particularly
impressive and will be flattening as it approaches. Marine layer
will be in place along/east of the highlands, with most
convection not being surface-based except perhaps the western
North Woods. Not expecting too much precipitation at the start
of the day Saturday, and lowered PoPs for all but the Downeast
coast. However, think that shower coverage generally increases
through the day as the upper trough approaches and remains more
active into the evening, with perhaps a few storms as well but
probably nothing severe. Always have to watch out for heavy
rain when you have an airmass this moist, but not seeing
anything to hang our hat on at this time. Went with broadbrush
likely (~60 percent) PoPs with a bit of categorical (80 percent)
PoPs western North Woods. Rain totals will vary substantially,
with some places getting nothing and some places exceeding an
inch, but really can`t pinpoint where the heavier totals will
favor at this point. Saturday will be a touch cooler thanks to
the cloudcover and showers, with highs mainly in the low to mid
70s. Quite muggy though.

Later Saturday night, precipitable water values fall and rain
chances decrease. The loss of moisture later Saturday night will
mainly be aloft, as the low levels stay moist and again we
expect fog for many areas, most prevalent near the coast but
possible anywhere. Very mild Saturday night with lows in the mid
to upper 60s.

Sunday...
The upper trough that had been approaching Saturday flattens
into upper level WSW flow for Sunday. Still lots of moisture at
low levels with a muggy airmass, but less mid/upper level
moisture than Saturday. Isolated to scattered mainly afternoon
showers and storms expected Saturday...about a 30-40 percent
chance of measurable precipitation. Highs back up into the low
to mid 80s, except a bit cooler as is often the case for the
immediate coast. Still muggy with dewpoints in the mid to upper
60s.

Sunday Night...
Expect generally dry conditions Sunday night once afternoon
convection dies off. However, moist low-levels and light winds
could lead to more fog. A touch cooler than Saturday night with
lows in the low to mid 60s, which is still easily above average.
&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Warm and muggy weather pattern persists for a while, with
nighttime fog common. Can`t rule out showers and storms any day
Monday to Thursday, but Monday appears to have the best odds at
being dry thanks to subtle ridging aloft and weak subsidence.
Went with 20 percent chance of showers/storms Monday afternoon.

Next upper level trough begins to approach Tuesday and moves
through around Wednesday. Precip chances are around 20-40
percent Tuesday, rise to 40-70 percent Wednesday, then fall to
around 30 percent Thursday behind the upper trough.
Thunderstorms possible any day, but best chance appears to be
Wednesday.

Temperatures next week will be warmest Monday and Tuesday, with
highs in the mid to upper 80s and some places topping 90 for
heat index thanks to muggy conditions. A bit less warm Wednesday
to Friday with highs roughly in the low 80s. Nighttime lows
remain mild with 60s until perhaps Thursday night, when there is
the hope of some 50s thanks to slightly drier air.

Models overall are in good agreement in the extended. Some
uncertainty in the timing of the next upper trough around
Wednesday, but overall pretty reasonable.
&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: Variable conditions this morning, ranging from VFR
to VLIFR, with areas of low clouds and fog. Generally VFR/MVFR
this afternoon with showers and thunderstorms. Variable
conditions possible with any thunderstorms which could produce
locally heavy rain. Conditions lower to IFR/LIFR, from south to
north, tonight. Areas of VLIFR also possible. Isolated to
scattered showers north tonight, scattered to numerous showers
Downeast. Variable winds 5 to 10 knots today through tonight.

SHORT TERM:
Saturday...Fog and IFR cigs may be persistent into the afternoon
for coastal sites and as far north as Bangor into midday. Other
sites will be MVFR or VFR in the afternoon. Afternoon
thunderstorms are possible for all sites. S wind 5-10 kts.

Saturday night...Fog and IFR cigs will most likely move north
from the coast to affect all sites again. Thunderstorms are
possible in the evening. Light S winds.

Sunday...IFR cigs will gradually lift to MVFR in the morning and
all sites will gradually become VFR in the afternoon. There is a
slight chance of thunderstorms in the afternoon for inland
locations. W/SW wind 5-10 kts.

Sunday night...IFR possible for any site later Sunday night in
fog. Light S/SW winds.

Monday into Tuesday...Mostly VFR except the threat of nighttime
fog and low clouds, most likely near the coast such as at BHB
but also possible inland. Light S/SW winds.
&&

.MARINE...
NEAR TERM: Winds/seas below small craft advisory levels today
through tonight. Visibilities reduced in fog today through
tonight. Scattered showers today, with scattered to numerous
showers tonight.

SHORT TERM: Favorable pattern for marine fog persists into the
middle of next week. Winds and seas should remain below small
craft levels.
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Dense Fog Advisory until 9 AM EDT this morning for MEZ029-030.
MARINE...None.

&&

$$


Near Term...Norcross
Short Term...Foisy
Long Term...Foisy
Aviation...Norcross/Foisy
Marine...Norcross/Foisy