Area Forecast Discussion
Issued by NWS Portland, ME
FXUS61 KGYX 290209
Area Forecast Discussion
National Weather Service Gray ME
1009 PM EDT SUN AUG 28 2016
.SYNOPSIS...A cold front will approach Maine and New Hampshire
tonight and move off the coast early monday morning. High pressure
will build over the region Monday and move of the coast Tuesday.
Another cold front will cross the area Wednesday. Cool high
pressure will build in over the remainder of the week.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
10 pm update: Thunderstorm activity in the mountains and
foothills has weakened as the atmosphere has been worked over.
Will continue the high pops but take out any enhanced wording for
some of the storms. Have made some adjustments to pops once again
with highest in the mountains of NH/ME. Southern areas will likely
remain dry although an isolated shower can`t be ruled out.
Considering the amount of mixing, took out the mention of fog
development for later tonight.
730 pm update: Showers and thunderstorms now moving into Northern
NH and Western ME with the heaviest cells moving into southern
Coos County. Have increase pops for northern areas and kept the
enhanced wording for northern areas into the evening. Have input
latest obs data and made some minor adjustments to temperatures.
525 pm update: A broad area of showers and thunderstorms have
developed and moved across far northern Vermont and will be moving
into northern NH in the next hour or two. Have raised pops across
northern areas of NH and western ME to account for this well
developed area. Have put some enhanced wording across these areas
just into the early evening. No other changes at this time.
Bona fide convection now moving into Vermont associated with a
frontal system. We have seen some echoes in our area but still
don`t think anything has reached the ground. However the
atmospheric column is apparently saturated enough across the far
north for rain to reach the ground. Dew points elsewhere are still
in the 50s with temperatures in the 70s and 80s.
PoPs are mainly confined to the higher terrain this afternoon and
overnight with a few sprinkles possible as far south as Lebanon
with the cold front. Also we may see something reach the mid
coast along the warm front...but in between there is not much
hope for measurable precipitation. Isolated to scattered
thunderstorms are possible as the better forcing arrives later
tonight into the overnight hours but no hazardous weather besides
lightning is expected. Storm total QPF values- where it does
rain- will range between 0.20" to 0.40".
The front moves offshore quickly tomorrow morning with clouds
disappearing quickly across the interior and coast. Across the
mountains some clouds will linger in upslope flow. Expecting gusty
winds up to 25 mph. Temperatures will warm into the 80s across the
south with locations closer to the Canadian border struggling to
get out of the 60s.SYNOPSIS...
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
High pressure builds across the areas on west winds with a drier
and cooler air mass.
.LONG TERM /TUESDAY THROUGH SUNDAY/...
High pressure over the region Tuesday should provide a mostly
sunny day with comfortable humidities and high temperatures from
the mid 70s to lower 80s. As the high slips offshore Tuesday
night...a cold front will approach the area...and then cross the
area Wednesday. Like many recent frontal passages any showers and
possible thunderstorms will be scattered...with the greatest
chance for rain in the mountains.
A cool Canadian high pressure system will follow the front for
Thursday and Friday. An upper level trough will swing through the
area Friday. At this time, this feature looks dry...but it could
kick off a shower in the mountains.
Dry weather is currently expected over the holiday weekend with
temperatures gradually warming.
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Short Term...A cold front will approach from the west tonight.
Widely scattered SHRA or TSRA could lead to MVFR or lower
conditions...especially across the CT River Valley. SHRA or an
isolated TSRA will sweep across the forecast area with the
front...with areas of MVFR and maybe local IFR in heavier
convection. Dense fog and stratus is likely for AUG...LEB...and
HIE. Coastal fog and stratus are likely for the mid coast and
but should stay east of Portland. Gusty west winds around 20 kts
Monday will clear things back out to VFR...except at HIE where
upslope clouds may keep some near MVFR CIGs. Another round of fog
is expected Monday night into Tuesday morning with radiational
cooling allowing temperatures to drop close to dew points.
Mainly VFR conditions expected through the period except for MVFR
conditions possible in scattered showers and possible
Short Term...Coastal fog/stratus will form by tonight. Seas and
winds increase tonight into tomorrow to 5-6 ft with a few wind
gusts to 25 kts. Waves will be a combination of swell from
Gaston and winds associated with a cold front.
Offshore seas will be near SCA criteria through Wednesday...then
expected to be below sca criteria Thursday and Friday.
MARINE...Small Craft Advisory until 8 AM EDT Tuesday for ANZ150>154.