695
FXUS61 KCAR 121626
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1226 PM EDT Sun May 12 2024

.SYNOPSIS...
High pressure remains across the region today, then exits
across the Maritimes Monday. A storm system approaches from the
west Monday night and Tuesday, crosses the region Wednesday,
then exits across the Maritimes Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
Just some high level cirrus and scattered cumulus across much
of the region at this time. Current temperatures were generally
in the mid to upper 50s and in line with current forecast highs
in the lower 60s. Thus, no changes with this update.

Previous discussion...
An upper level low remains over the area while surface high
pressure centered over the Maritimes continues to ridge over the
forecast area. The very dry surface high is the dominant
feature as no shower activity is anticipated and winds will be
light. While an area of stratocumulus has slowly advected
westward out of the forecast area this morning, there will be
enough moisture in the H8 to H7 layer to generate scattered to
occasionally broken fair weather cumulus fields this afternoon.
A very deep mixed layer is expected today and that led to
increases in the high temp forecast into the low to mid 60s
except near the coast where a sea breeze will develop in the
afternoon. The mixing also led to reductions in the dew points
and afternoon relative humidity.

For tonight, the upper level low fills and upper ridging builds
from the west. Clear skies and light winds will promote good
radiational cooling under a steep and shallow inversion. Do not
expect any frost headlines given that the zones active in the
frost/freeze program are primarily near Bangor and Downeast
where lows will be near 40F. Further north, some patchy frost
can be expected with lows in the mid to upper 30s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
High pressure begins to slide east over the Maritimes on Monday.
This will mean return southerly flow setting up over the area.
With at least partial sunshine, went a bit above NBM guidance
for lower elevations in central and northern areas. Expecting
highs in the mid to upper 60s for these areas. Went a bit below
NBM values for coastal areas due to onshore flow, resulting in
50s there. Highs will be in the lower to mid 60s for the Bangor
region and Interior Downeast.

A warm front will lift approach the area Monday night and cross
on Tuesday. A cold front will then move in from the northwest
later Tuesday. This will bring rain to areas north and west of
the Katahdin region, with lesser chances of showers to the south
and east. Given onshore flow and mostly cloudy skies, there will
not be enough instability for thunder. Highs on Tuesday will
be in the 50s to near 60 degrees.

The cold front will make some more progress further south and
east Tuesday night, and waves will start to ride the front. This
will increase the threat of showers and steadier rain further
southeast. Patchy to areas of fog will also be possible Tuesday
night with moisture around and relatively light winds.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The front will still be nearby on Wednesday with weak waves
riding along it. The overrunning from this setup will likely
bring a period of rain across the area during the day Wednesday.
Meanwhile, a low pressure system will develop near the Mid-
Atlantic coast. Models have come into better agreement with this
low tracking east-northeastward offshore Wednesday night and
Thursday. This will shift rain activity southward with gradually
decreasing PoPs. High pressure builds in Thursday night and
Friday, with temperatures undergoing a warming trend. Another
system will approach from the west over the weekend with the
threat of showers. However, there are still significant timing
differences amongst model guidance, so stuck with NBM PoPs.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: VFR with light winds at all terminals through
tonight.

SHORT TERM:
Monday...VFR at all terminals. S winds 5-10 kts.

Monday Night and Tuesday...Trending to MVFR with showers/rain.
IFR or lower possible at BGR and Downeast terminals Monday night
and early Tuesday AM with patchy fog. S winds 5-10 kts Monday
night, increasing to 10-15 kts on Tuesday with gusts to 20-25
kts.

Tuesday night through Wednesday night...MVFR/IFR. S to SE winds
5-10 kts. Showers/rain/patchy fog.

Thursday...Mainly VFR. BCFG early AM at BGR and Downeast
terminals. Light N winds.

&&

.MARINE...
NEAR TERM: No significant weather is expected. No fog is
forecast. Seas will be generally 2 feet or less. Light NE winds
will become variable this afternoon and then southwesterly
tonight.

SHORT TERM: Winds and seas remain below Small Craft Advisory
levels through Monday night. Patchy fog could reduce visibility
on the waters Monday night. Seas and wind gusts build to around
SCA criteria Tuesday into Tuesday night, before subsiding on
Wednesday. Rain and fog could reduce visibility Tuesday night
through early Thursday morning.

&&

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

&&

$$


Near Term...TWD/MCW
Short Term...Clark
Long Term...Clark
Aviation...TWD/MCW/Clark
Marine...TWD/MCW/Clark