530
FXUS61 KCAR 170731
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
331 AM EDT Wed Jul 17 2024

.SYNOPSIS...
High pressure will remain to our south today. A weak weather
disturbance will cross the area tonight followed by a cold front on
Thursday. High pressure will build in from the west on Friday.
Another cold front will cross the area Saturday followed by high
pressure on Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Lingering showers will continue to push eastward out of the
region early this morning, with the heaviest rain just exiting
the CWA shortly before sunrise. Behind this recent disturbance,
a brief pause in rain showers will take place. During this time,
surface capping will allow for CAPE to build under diurnal
heating. This, combined with yet another small 500 mb vort max,
will lead to another round of showers and storms developing
through the afternoon. MUCAPE may max out around 1000 J/kg,
while bulk shear continues to build through the day to near 40
kts. The most unfavorable ingredient for convective development
of the current synoptic setup, as has been the past few days,
are the lapse rates, which in the low levels may briefly
approach 7 C/km this afternoon across interior Downeast, but
mid level lapse rates will likely remain closer to 5 C/km.
Forecast soundings do indicate a bit more of wider CAPE profile
than seen the past couple days, and a shallow inverted V
signature. Given all these ingredients, there is the chance for
any stronger storms this afternoon to contain gusty winds. PWs
will also increase through the day and into the evening hours,
approaching 2 inches which is well above the average for this
time of the year. Elevated moisture and deep warm cloud layer
will provide a favorable environment for efficient rainfall
processes, leading to locally heavy rain which could lead to
ponding and localized flooding in poor drainage areas.

Today will also be warm and muggy again, with high temperatures
lifting into the mid to upper 80s across the forecast area,
aside from the immediate coast where the marine influence will
keep temperatures more mild. Dewpoints will continue to persist
in the upper 60s to lower 70s, leading to heat indices (what it
feels like) surging into the upper 80s to lower 90s. A few spots
Downeast, particularly around Bangor, will see heat indices lift
further into the mid to upper 90s, and a heat advisory remains
in effect for southern Penobscot county.

Relief from the heat will begin to work its way in tonight in
the form of an approaching cold front. With the next synoptic
disturbance in spitting distance overnight, another plume of
showers and storms may lift into the area, with general
consensus across CAMs zoning in on Downeast as the region for
another round of nocturnal rainfall. With efficient rain
ingredients still in play, locally heavy rainfall remains a
threat through the night tonight, particularly across the
Downeast area, but this threat could shift northwards pending
future trends.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A cold front will push across the area Thursday ahead of an upper
trough lifting up to our west. A corridor of moisture ahead of the
front in the humid air circulating north of the subtropical ridge
may bring some showers to mainly southern and eastern areas Thursday
morning. Slightly cooler air and drier air will begin to filter into
the area following the front Thursday afternoon. Some cooler air
aloft associated with the upper trough will result in some low low
level instability with CAPEs up to 200 J/JG up to 15K ft so will
have chance thunderstorms Thursday afternoon. Otherwise, Thursday
will bring partial clearing as the front pushes in.

High pressure will build in from the west Thursday night bringing a
clear and cooler night with lower humidity than recent nights. The
clear and tranquil air will likely allow some patchy ground fog to
form late at night. The drier air will allow temperatures to fall
into the mid to upper 50s in most areas.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure will bring a sunny and seasonably cooler day on Friday
with highs topping out from the upper 70s north to the lower 80s
across interior Downeast. A light southwesterly breeze will increase
Friday afternoon well ahead of a cold front approaching from the
northwest. Friday night will be clear and comfortable ahead of the
cold front.

The cold front will continue to approach on Saturday reaching
northern areas early Saturday afternoon then continuing Downeast
reaching the coast early Saturday evening. Given the timing of the
front, some isolated thunderstorms will be possible across the area,
mainly early afternoon north and late Saturday south. Winds will be
strong aloft in the gradient south of an upper trough in Eastern
Canada. This will give any thunderstorm a potential for gusty winds.
Cooler and drier air will follow the front Saturday night with lows
from the low 50s north to the low 60s south.

High pressure will bring sunshine dotted with a few fair weather
cumulus clouds on Sunday with highs from the low 70s north to near
80 south with low humidity. This will be followed by a mostly clear
and cool night Saturday night with some northern spots possibly
dropping into the 40s in the cooler valleys.

High pressure will remain over the area Monday with another
relatively cool day. A bit of mid and upper level moisture rounding
the bottom of the Eastern Canadian trough may bring patchy
cloudiness on Monday. Otherwise, Monday should be partly sunny and
dry.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: Generally VFR conditions will persist across all
terminals through the early morning hours, though brief MVFR or
IFR is possible in any heavier rain showers, as has been
recently seen at HUL. VFR to continue through the day on
today, though again brief MVFR or IFR remain possible in
afternoon showers and storms. Winds will increase this afternoon
to 5 to 10 kts out of the SW, with gusts 20 kts or more possible
in thunderstorms. Light and variable winds return tonight, with
decreasing cigs in rain. Sites most likely to return to
MVFR/IFR in rain will be south of a line from GNR through HUL.

SHORT TERM:
Thursday...VFR. Light W wind

Thursday night...VFR except in any patchy fog late at night. Light W
wind becoming calm.

Friday...VFR. Light W wind.

Friday night...VFR. Light SW wind.

Saturday...VFR except in any shower or thunderstorm. Light SW wind.

Saturday night...VFR. Light NW wind

Sunday...VFR. Light NW wind.


&&

.MARINE...
NEAR TERM: Winds and seas will generally remain below small
craft advisory levels through tonight, though a few gusts to 25
kts are possible through the early morning hours on the coastal
waters, and seas may approach 5 ft on the outermost reaches of
the coastal waters. Patchy fog may reduce visibility to around 1
mile at times through the day today.

SHORT TERM:
Wind and seas will remain below SCA Thursday through the coming
weekend. Humid air over the cooler waters may result in some fog
or mist Thursday into Thursday night. A moderate decrease in
humidity Friday into the weekend should result in improving
visibilities Friday into the weekend.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from 2 PM to 5 PM EDT this afternoon for MEZ015.
MARINE...None.

&&

$$


Near Term...AStrauser
Short Term...Bloomer
Long Term...Bloomer
Aviation...AStrauser/Bloomer
Marine...AStrauser/Bloomer