744
FXUS61 KCAR 160818
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
418 AM EDT Tue Jul 16 2024

.SYNOPSIS...
Several weak troughs of low pressure will cross the area through
Wednesday. A cold front crosses the region Wednesday night and
early Thursday morning. A trough of low pressure passes through
the area Thursday, followed by high pressure building in through
Friday night. A cold front approaches from the west on
Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Early this morning, a line of showers and storms is making its
way into the forecast area from the west. Though storms are more
isolated in nature this morning, any thunderstorm that does move
into the region has the potential for heavy rain. CAPE remains
elevated above the nocturnal inversion, but is nonzero at around
400 J/kg. Additionally, mid level lapse rates are marginal at
around 6 C/km across the northeastern portion of the CWA.
Effective shear also is low to marginal at around 20 kts, though
locally higher shear can be seen in areas of active storms at
this time. All of these ingredients together lead to the
continued support for some isolated morning convection to
continue to roll across the northern half of the CWA.

Downeast, fog continues to roll inland from the coast, and
patchy dense fog is expected along the immediate coast.

The current line of showers and storms will move out to the east
through the late morning hours, but more showers and storms may
develop through the afternoon due to diurnal heating. Once
again, as PWs lift above 1.5 inches across the area (which is
significantly above the average of closer to 1.1 inches this
time of year) and the warm cloud layer remains deep with
substantial warmth in the area, efficient rain processes remain
a threat. Any storms that develop through the afternoon could
contain heavy rainfall that may lead to localized ponding and
flooding of low lying and poor drainage areas.

Mostly cloudy skies through much of the day will limit incoming
solar radiation, but southwesterly flow under the current
synoptic setup will support continued warm, moist air advection
into the region, and maintain elevated heat indices (what it
feels like). The Heat Advisory remains for Southern Penobscot
County, and most of the rest of the forecast area will also see
heat indices rise into the upper 80s to lower 90s today.
Remember to avoid overexertion during peak heating hours and
stay hydrated. Warmth will continue into the night tonight, with
lows only falling into the upper 60s to lower 70s, and dewpoints
remaining in the mid to upper 60s. This will offer little relief
after heat of the day.


&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The region is under SW flow aloft Wednesday and Wednesday night.
Shortwaves embedded in the flow will trigger isolated to
scattered showers and thunderstorms during the afternoon/evening
hours. CAPES are now progged only in the 400-800 J/kg range, but
still see 40-45KT of bulk shear Wednesday afternoon/early
evening - so there is still the potential for strong to
possibly isolated severe thunderstorms, with the main threat
being strong gusty winds. Precipitable waters are forecast in
the 1.5-2.25 inch range (lowest far NW zones - highest over
southern portions of the central highlands/Bangor Region) - so
locally heavy rainfall is a threat as well. This could produce
minor flooding of known poor drainage/low lying areas and an
isolated flash flood cannot be completely ruled out. The threat
for strong/severe storms and locally heavy rainfall will
continued to be highlighted in the HWO.

Wednesday also will be another hot day with highs running from
around 80 over N Somerset to around 90 across portions of the
Central Highlands, the Bangor/Penobscot Region and interior
Downeast Maine. Dewpoints in the latter area should be around 70
with resulting heat indices likely into the lower-mid 90s. If
things hold, a heat advisory could be required for at least
portions of the southern Central Highlands, Bangor/Penobscot
Region and interior Downeast Maine Wednesday. Lows Wednesday
night should be around 10 degrees above normal.

A northern stream trough approaches Thursday, then moves into
the region Thursday night. The passage of the 850 mb cold front
Thursday (which is lagging a bit behind the surface cold front)
could result in more isolated to scattered showers, with
possibly some elevated thunder as well, especially over the NW
1/2 of the region. The low levels dry out Thursday night, and
other than possibly some lingering showers early in the evening,
it should be dry. It will be noticeably less humid on Thursday,
with dewpoints falling through the 60s during the day and even
into the mid to upper 50s in the North Woods by late afternoon.
Highs on Thursday should be near to slightly above normal and
around 5 or so degrees cooler than on Wednesday. Lows on
Thursday night should be near normal.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A northern stream trough exits to the east on Friday, the low to
mid levels should be sufficiently dry to preclude any precipitation.

The region should be under WSW flow aloft Saturday into
Saturday night as it remains on the base of a northern stream
closed low centered over N Central Quebec. The axis of this low
then translates to the east sometime late Saturday or Sunday.
The models differ on the timing, strength and impact of this
system. For now have slight chance pops late Saturday
afternoon/night over NW portions of the area, then on Sunday
from Northern Downeast Maine on north.

The region then remains at the base of the close low as it lifts
into the Maritimes and transitions to an east-west orientation.
This should help to keep most forcing to our north, and the
region dry Sunday night and Monday as a result.

Temperatures should be near to slightly above normal Friday-
Saturday night, then below normal across most of the North and
near normal elsewhere Sunday-Monday.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: Generally VFR conditions to continue across northern
terminals over the next 24 hours. BHB is likely to quickly drop
to LIFR as fog moves in from the waters, and may be slow to
improve through the morning. BGR may see a brief drop in cigs
and vis as the fog pushes further inland, but is just far enough
inland where they could also stay VFR through the night. A line
of showers and storms will push into the area through the early
morning hours, and should stay north of BGR, hence no VCTS in
the TAF. However, GNR up through FVE has a chance of seeing
early morning lightning. Chance for showers and storms through
the day on Tuesday across all terminals, with brief MVFR
conditions possible in any rain. A return of IFR is possible at
BHB and any terminal which sees rain during the day on Tuesday
into Tuesday night. Winds light and variable through the early
morning hours, becoming SW at 5 to 10 kts with gusts to 20 kts
or higher in any storms. Light and variable winds return Tuesday
night.

SHORT TERM:
Wednesday-Wednesday night...VFR, except MVFR possible in any fog
Wednesday morning and with any stronger convection/thunderstorms
Wednesday afternoon/evening.

Thursday...VFR, except for brief periods of MVFR possible in any
showers. W_NW winds G15KT possible.

Thursday night-Saturday...VFR. W winds G15-20KT possible
Saturday.

&&

.MARINE...
NEAR TERM: Conditions should remain below small craft advisory
levels through today and tonight, though winds may gust 20 kts
on the coastal waters and seas could approach 5 ft on the
outermost reaches of the coastal waters. Patchy dense fog may
remain on the waters through today and into the night tonight,
reducing visibility to below 1 NM at times.

SHORT TERM: Marine fog could limit visibilities to under 1nm
Wednesday morning and again from Wednesday night into Thursday.
The coastal ocean waters should see wind gusts and/or seas just
under SCA limits Wednesday- Thursday night, with the intra-
coastal waters well below SCA limits. All waters should be well
below SCA levels Friday- Saturday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from 2 PM this afternoon to 6 PM EDT this
     evening for MEZ015.
MARINE...None.

&&

$$


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