150 
FXUS61 KCAR 091036
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
636 AM EDT Tue May 9 2023

.SYNOPSIS...
High pressure will build across the region through mid-week. A
weak disturbance tracks to our southwest on Thursday. A cold 
front will cross the region later Friday into Saturday morning. 
High pressure settles in from the northwest on Sunday.
&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
Have updated to adjust for current conditions, mostly 
temperatures.

Previous Discussion...
Upper level low pressure will remain near Newfoundland today 
through tonight, while surface high pressure builds toward the 
region. A disturbance, with limited moisture, rotating around 
the upper low will also cross the region today. Due to the 
limited moisture, expect that any showers should remain across 
New Brunswick. Otherwise, expect mostly/partly sunny skies 
today. Northwest/north winds will gust to 25 to 30 mph. Expect 
mostly clear skies tonight. High temperatures today will range 
from the mid to upper 50s north, to the upper 50s to around 60 
Downeast. Low temperatures tonight will range from around 30 to 
the lower 30s north, to the lower to mid 30s Downeast.
&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Models are in very good agreement with generally surface high 
pressure in control with NW flow on the northeast side of 500mb 
ridging. Expect a dry day on Wednesday with mainly mostly sunny
skies. RAP vertically integrated smoke model suggests some 
upper level haze is possible Wednesday into Wednesday evening 
thanks to smoke from wildfires in Alberta Canada. Expect a well 
mixed afternoon with mixing up to 700mb expected. This will 
allow for relative humidity to fall into the 20-25% range across
the area (see the fire weather section below). NW winds will be
10-20mph with some gusts up to 30mph possible. Temperatures 
will be warmer than today in the low to mid 60s across the north
but the downslope of the Longfellow Mtns will allow for upper 
60s in Bangor to the Downeast coast. 

Mostly clear night into Thursday AM with temperatures bottoming
out in the mid 40s across the southern 1/2 of the CWA with 
upper 30s to low 40s across the North. It is a warmer air mass 
working into the area so the debate was how low do temps get in 
the morning with light winds, calm skies and dry air. Opted to 
lower temperatures a degree or two below previous forecast and 
NBM guidance. During the day model guidance is consistent with a
500mb shortwave diving SE over western New England keeping any 
extra clouds or showers far to our west. Strong daytime heating 
combined with 850mb temps warming to between +6C and +8C will 
result in highs in the 70s nearly CWA wide. Low 70s across the 
north (minus some upper 60s along Quebec border) and mid 70s for
Bangor, Dover- Foxcroft, Danforth and even Bar Harbor. 
Expecting the NW downslope winds to continue so the only cool 
spots will be the islands thanks to the colder Gulf of Maine 
waters. Thursday night expect high pressure to slowly shift
southeast around Bermuda which will allow for energy to dive SE
in the 500mb flow over Ontario & Quebec. A cold front will be
pushing into Quebec during the night. Here in Maine expect
generally slowly increasing high cloud cover with temperatures
falling back into the low to mid 40s.
&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Friday will be our best chance of precipitation especially
across the north and Central Highlands. There remains some
model difference of timing of the surface cold front pushing
into Maine from the northwest. Very decent agreement on strong
warm air advection on southwest winds. Expecting high
temperatures in the low to mid 70s from north to south with
exception along the Downeast coast where a sea breeze develops
late morning. Modeled soundings are suggesting some MUCAPE but
this far out only seeing up to 250j/kg. Mid May convection
doesn't require too much but there is some question how strong
daytime heating will be. For now opted to increase shower
chances during the day with likely POPs over the northern 1/2 of
CWA by afternoon. Will paint a slight chance of thunder for now
based on the soundings. There is some things in the modeled
soundings supportive of convection including steep Sfc-3km lapse
rates around 8-8.5C/km, 850-500 lapse rates around 7C/km and
likely reaching the convective temp around 70-74F. 

Friday night expecting a chance of showers with the cold front
slightly delayed behind the daytime activity. Expect FROPA to
occur between midnight and daybreak Saturday given the timing
differences. Saturday will be cooler across the north as breezy
NW winds develop. Gusts may approach 30-35mph across much of 
the area as RHs fall back into the 35-40% range. Temperatures 
will be in the upper 50s to low 60s across the north and 
downslope of the Longfellows will all for mid to upper 60s in 
Bangor, Bar Harbor to Calais and points in between. A chance of 
showers in the morning along the New Brunswick border before 
becoming a dry afternoon. High pressure will settle in from the 
northwest on Sunday with mainly another well mixed day with 
mostly sunny skies. NW winds 15-25mph with some higher gusts, 
RHs falling back into the 20-30% range and highs in the low to 
mid 60s. 

Another system is possible by early next week, however there is
significant model differences. This can be seen in the large
spread of members predicting the NAO pattern. The PNA is
expected to remain positive around +1SD suggesting some
troughing but system strength and track will be determined by 
NAO pattern. At this point given the signature in the 
operational runs opted to keep NBM slight chance POPs with 
slightly above normal temps.
&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions today through tonight. 
Northwest/north winds 10 to 20 knots with gusts up to 25 knots 
today, except becoming west/southwest along the Downeast coast 
this afternoon. West/northwest winds 5 to 10 knots tonight.

SHORT TERM: Wed-Thu...VFR. Wed expect winds NW 10-15kts with
gusts to 25kts possible. Thu expect winds NW winds 5-15kts with
a few gusts to 20kts. 

Fri...VFR. Possible brief MVFR/IFR with scattered SHRA/TS in the
afternoon from BGR northward. Chance SHRA at BHB. SW winds
10-15kts. Winds will shift W late evening with FROPA.

Sat...VFR/MVFR due to VCSH before noon becoming SKC late day. NW
winds 10-20kts with higher gusts possible.
&&

.MARINE...
NEAR TERM: Winds/seas below small craft advisory levels today
through tonight.

SHORT TERM: Winds/seas likely remaining below SCA through the
weekend. A few wind gusts to 25kt possible in the evening Wed 
mainly across far outer waters. Otherwise gusts generally less 
than 20kt through the weekend. Seas 2-3ft Wed-Thu, 1-2ft Fri-
Sun. Fri-Sat there is a chance of showers.
&&

.FIRE WEATHER...
No precipitation is expected through Thursday night. Dry 
Canadian high pressure will provide low afternoon relative 
humidity through Wednesday generally in the 20-25% range. 
Minimum relative humidity will begin to recover on Thursday 
closer to 30%. Northwest winds are expected to remain gusty 
through Wednesday but not as strong with gusts 20-30 mph 
possible. Northwest winds will become 10-20 mph by Thursday. 
Temperatures will be warming through the rest of the week with 
highs in the 50s to 60F today becoming low to mid 70s by 
Thursday. Therefore, elevated fire weather conditions are 
possible through Thursday afternoon. Showers and possible 
thunderstorms will develop on Friday but a widespread wetting 
rain isn't expected.
&&

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

&&

$$

Near Term...Norcross
Short Term...Sinko
Long Term...Sinko
Aviation...Norcross/Sinko
Marine...Norcross/Sinko
Fire Weather...Sinko