237
FXUS61 KCAR 082216
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
616 PM EDT Mon Jul 8 2024

.SYNOPSIS...
High pressure remains through the night tonight. A weak surface
trough crosses the area on Tuesday. Low pressure then
approaches from the west Wednesday through the end of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
6:16 PM Update...Expanded the area of isolated showers for the
next couple of hours based on radar trends. This is mainly for
the Crown of Maine. Also, webcams show fog bank approaching the
coast. Thus, covered all of the waters with at least patchy fog
early this evening. Expect fog coverage to increase tonight.

Previous Discussion...
High pressure remains in place this evening through the night
tonight, with continued light to calm winds and partly to mostly
clear skies. The few showers that developed late this afternoon
will quickly dissipate into the overnight hours. That said, low
level moisture content remains elevated, especially anywhere
which recently received rain, and fog development is likely
tonight. The densest fog is expected to form in any areas where
it recently rained. Additionally, marine layer low stratus and
fog will advect in overnight tonight, and could lead to locally
dense fog along the coast. In any areas of dense fog, remember
to slow down, use your headlights, and leave plenty of distance
ahead of you. Low temperatures tonight will remain mild in the
low to mid 60s.

A weak front will sag southwards through the forecast area
during the day on Tuesday, leading to an increased chance for
showers and storms, particularly Tuesday afternoon. High
temperatures will be warmest prior to the FROPA, and could lift
into the mid to upper 80s once again. As dewpoints will remain
in the upper 60s to lower 70s, heat indices will be elevated
once again, with the potential to reach into the lower 90s.
Remember to drink plenty of fluids and stay out of the sun if
possible during peak heating hours in the mid to late afternoon.

For the threat for storms Tuesday afternoon, CAMs guidance,
though not in total agreement on location of any convective
development, is in agreement that CAPE will increase to at least
1000 J/kg across the Central Highlands into the Interior
Downeast region. In this same area, bulk shear could approach 40
kts and low level lapse rates may exceed 7 C/km. Given these
ingredients, there is a brief window, particularly in the
Central Highlands, where thunderstorms could become strong to
severe, with the greatest threat being that of strong winds. The
threat for hail and locally heavy rain can also not be ruled out
with these storms given the persistent moisture and marginal but
existent ingredients. With freezing levels forecast to exceed
12 kft under the multi-day warm sector influence, there is a
good chance for any hail to melt, which could enhance the threat
for gusty winds with any storms that do develop.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Main concern is potential heavy rain from remnants of Beryl,
with the greatest period of concern being Wednesday afternoon
through Thursday morning. Tuesday night into Wednesday morning
look relatively quiet, with fog for many areas yet again Tuesday
night. Can`t rule out a few showers Tuesday night into Wednesday
morning, with PoPs generally 10 to 30 percent. Then moisture
begins to move in from the west from Beryl. A situation appears
to be setting up where a trough axis/front extends east from
Beryl`s remnant center, moving NE through Lake Erie and Ontario
at the time. Extremely high precipitable water values
along/south of this front will lead to potentially very heavy
rain, but likely for a narrow corridor along the front. The
problem is, models/ensembles still disagree badly on where this
front or east/west oriented area of heavy rain will be. General
trend has been a bit northward, and adjusted forecast
accordingly, with the highest PoPs/QPF over central portions of
our area. However, this could easily change. The bottom line is
the potential is there for rainfall exceeding 2 inches within 18
hours or so somewhere over Maine, with even some ensembles
hinting at the possibility of over 4 inches within 18 hours.
Models are extremely uncertain though, and while it`s something
to watch, we can`t yet pin down locations and whether the rain
will be enough to cause impactful flooding. Heading into late
Thursday, it tentatively appears the heaviest rain will ease,
but it could keep raining at least some, and kept likely PoPs
for much of the area into Thursday afternoon. Winds, coastal
flooding, and strong/severe thunderstorms are not a concern with
Beryl.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Thursday night through early Saturday, there is very low
confidence in the forecast. We should remain under mid/upper
level SW flow. The problem is, there is the potential for the
extreme precipitable water plume to persist especially over
southern portions of the area, and this could bring a more rain
on top of what`s already fallen. However, the majority of
models keep this precipitable water plume just to our south,
while a notable minority have it over Downeast. Something to
watch closely. We can say with confidence that a warm and moist
airmass at low-levels will persist Thursday night through the
weekend with above average temperatures and dewpoints...it`s
just the uncertainty in the amount of upper level moisture.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions continue into the early evening hours
across all terminals with cigs around 5 kft. Fog once again
becomes a threat tonight in two forms. There is a good chance
(70%) that low cigs and possible low vis will move onshore from
the waters tonight, leading to LIFR conditions at BHB. But if
onshore winds become calm, this threat will diminish. Then for
inland terminals, fog may develop overnight, with greatest
chance being anywhere which received rain today. A return to VFR
conditions is expected for Tuesday morning and should linger
through the day on Tuesday, though brief periods of MVFR are
possible in any showers and storms.

SHORT TERM:
Tue night to Wed...Highly variable conditions, with areas of
IFR/LIFR in fog and low clouds, but also some spots of VFR.
Light winds. Generally VFR Wed afternoon.

Wed Night and Thu Morn...Becoming generally MVFR with possible
IFR, with likely rain and possible storms. E/SE winds 5-10 kts.

Thu afternoon through Sat...Much lower confidence than average
for this period. Likely periods of IFR in the late night/early
AM hours, especially near the coast. However, low confidence in
amount of precipitation and in afternoon aviation conditions.
Variable winds less than 10 kts.

&&

.MARINE...
NEAR TERM: Winds and seas will remain below small craft advisory
levels tonight through Tuesday. Visibility may remain below 1 SM
or fall below 1 SM tonight in fog, and reduced visibilities
could last through the day on Tuesday as well.

SHORT TERM: Winds/seas will generally be below small craft
levels, but could approach small craft Fri/Fri night. Marine fog
will be common, especially in the late night/early morning
hours.

&&

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

&&

$$


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