NWS Caribou, Maine Area Forecast Discussion



000
FXUS61 KCAR 031731
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
131 PM EDT Fri Apr 3 2020

.SYNOPSIS...
A strong area of low pressure will continue to pull away to the
south of New England through tonight. High pressure will build
into the region tonight into Sunday. A weak frontal system will
cross the area Sunday night. Weak high pressure will then build
back in Monday into Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
130 pm update...
Quick update to increase pops to likely across Downeast zones
for the next few hrs as band of showers continues to slide east
while slowly sinking south. Other than a quick tweak to temps no
other chgs are needed at this time as winds rmn high in strong
pressure gradient.

Previous discussion:
Low pressure is visible on satellite pictures approximately 200
miles east of Cape Cod early this morning. The low will continue
to rotate counterclockwise during the next 24 hours and slowly
fill. By 12Z Saturday morning the low will be several hundred
miles off the VA/NC coasts. Strong high pressure currently over
Labrador will slowly build south toward the region with a much
drier air mass.

Drier air continues to filter in tonight with the gradient and wind
to slowly relax.  Lows will drop back into the mid to upper 20s
across the the Crown of Maine to the lower 30s Downeast.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The persistent NE flow associated with exiting low pressure
tracking into the open Atlantic will continue to weaken
Saturday. Weak high pressure slides to the north which will help
keep surface winds light as much of the winds through the mid-
levels remain quite calm. Some reduction in cloud cover is
anticipated, however lingering moisture will likely keep skies
mostly cloudy. Thinning of the clouds will enhance some of the
temperatures, continued to show Sat highs a couple degrees
warmer than prev days offering a break from the damp and mild
mid-week.

Dry weather continues Sat night through early Sunday afternoon.
What breaks in the clouds exist Sun morning will begin to fill
in by the afternoon as a weak cold front approaches from the NW.


The cold front will be associated with a small shortwave
tracking across central Quebec, over the Gaspe Peninsula, and
into eastern New Brunswick Sun night. Zonal 500 mb jet rounding
the top of a ridge over the northern Great Lakes prevents much
southerly moisture transport towards this weak disturbance.
Thus, expect QPF to be quite light with a chance of rain showers
late Sunday evening, and a few snow showers mixing in later on
across the north.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The cold fronts passage will be strong enough to generate some
breezy conditions Monday especially with any afternoon mixing
that occurs amid low-level lapse rates around 7c/km. April sun
will help Downeast and the Bangor region into the lower to mid-
50s, while the north rises to the mid-40s.

Flow behind the system will put Maine back in a NW regime,
setting up cooler nights for the forecast area Mon and Tues
night. Northern and central areas will see lows into the lower
to mid- 20s, with temperatures dipping to around 30 across
Downeast.

Attention then turns towards mid to late week as guidance
suggests the arrival of a complex system to the region. The GFS
and Canadian models both depict a low tracking quickly through
the Great Lakes towards the Northeast. Ideas converge here on
how the system impacts the region. The more progressive GFS and
Canadian run a low through southern New England with parent
upper low remaining across Ontario/Quebec. This drapes a
elongated trough between the two lows, and precip Wed-Fri across
most of Maine. On exit, the primary low intensifies over the
Gulf of Maine, prolonging precip over the region.

The EPS agrees with the later intensification, however is much
weaker surrounding the mid-week trough idea. Because of the
disagreement, continue to keep low chance PoPs through this
period, with much to be decided on temporal extent of precip and
temperatures for precip type. In any case, if prolonged precip
can be expected, will need to monitor the hydrology situation
across northern and eastern Maine as some snowpack continues to
ripen through the week.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: MVFR expected through the overnight hours at all but
KCAR and KPQI where drier low-level air may be able to work in
after 02z tonight. Remaining terminals will improve to VFR by
mid-morning tomorrow as clouds begin to rise and slowly scatter
out. LLWS will only be effect BHB this afternoon into evening
while remaining terminals see winds diminish aloft.

SHORT TERM:
Saturday...MVFR cigs across the north with NE winds decreasing
and becoming light by the afternoon. BGR and BHB may improve
towards VFR in the afternoon and evening.

Saturday night into Sunday...Mainly MVFR with breaks of VFR
possible. Light and variable winds, turning SSW late Sunday.

Sunday night through Monday night...MVFR to IFR early with rain
showers. Some snow showers may mix in across northern sites
after midnight. Light SW winds early, shifting NW and
increasing late Sunday night. Gusts up to 25 kts possible during
the day Monday.

Tuesday...MVFR possible with NW winds slackening.

&&

.MARINE...
NEAR TERM:
A gale warning remains in effect along the coastal waters
through tonight.  The gale warning runs through 6 pm on the intra-
coastal waters.  The timing looks very reasonable and could need to
be adjusted by a few hours either way as far as an adjustment to a
small craft advisory.

SHORT TERM:
SCA conditions will be ongoing Saturday as waves and winds will
continue to decrease. Both fields should fall below SCA criteria
by early Saturday night as low pressure continues to pull away
into the open Atlantic. Waves are expected to fall to 2 to 4 ft
through Tuesday, with breezy conditions Monday afternoon as a
cold front w/ rain passes, but remaining below SCA criteria.

&&

.TIDES/COASTAL FLOODING...
A storm surge of up to 2 feet will continue into tonight due to the
long duration northeast flow around the ocean storm.
Astronomical  tides are low, but given the persistent fetch
areas susceptible to northeast flow will likely have some minor
splash-over/overwash. Will issue a statement to cover both the
high tides this morning and early this evening. The statement
will likely need to be extended for one or two additional high
tide cycles into Saturday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Gale Warning until 6 PM EDT this evening for ANZ052.
     Gale Warning until 6 AM EDT Saturday for ANZ050-051.

&&

$$

Near Term...CB/Farrar
Short Term...Cornwell
Long Term...Cornwell
Aviation...CB/Farrar/Cornwell
Marine...CB/Farrar/Cornwell
Tides/Coastal Flooding...

NWS CAR Office Area Forecast Discussion