Area Forecast Discussion
Issued by NWS Portland, ME
FXUS61 KGYX 300736
Area Forecast Discussion
National Weather Service Gray ME
336 AM EDT Fri Sep 30 2016
High pressure over eastern Canada will produce a moist northeast
flow across the waters into the upcoming weekend. Low pressure
will approach from the west on Sunday and will cross the waters on
Monday before heading out to sea on Tuesday as high pressure
builds in from the northeast. High pressure will hold over the
region Wednesday through Friday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Large closed cyclone at 500 mb will remain settled over the mid
west CONUS and this will allow 500 ridge to hold over the CWA
today. Moisture will gradually work in from the south at mid-
upper levels moving into diffluent flow, so could see some rain
start to fall from 8-10K foot clouds, but not much of it will make
it to the ground, if any, and this will occur over southern NH, as
NE flow transports drier air in below 850mb. Otherwise look for
thickening cirrus and eventually mid level clouds to spread north
and east today. Highs will range from around 60 in srn NH, where
there will be more clouds, to the mid 60s in the northern which
see at least some filtered sunshine through the cirrus for a good
part of the day.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
The ridging aloft hangs on through Saturday, and the thinking is
that the steady flow of moisture aloft will eventually pile up
and produce enough to rain to make cotit to the ground in
southern areas by late Friday into Saturday. Still, the dry layer
below will be enough to evaporate a lot of this rain and while
there are lkly pops in the south, QPF will likely be very low,
maybe less than a tenth of an inch. It certainly won`t rain all
day, with just some scattered showers. In the northern and eastern
zones, could see a few more isolated showers develop during the
day Saturday, but those too, will be light.
Lows tonight will be mainly in the mid-upper 40s, a little cooler
in Somerset and Franklin counties, and around 50 in the MHT/ASH
area and the seacoast of NH. Highs on Sat will be a couple degrees
cooler than Friday as more clouds and a little stronger NE flow
reinforces the cool air, highs in the upper 50s along the coast
and srn NH to low 60s in the north and east.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Closed upper low will continue to meander over the southern Great
Lakes Saturday night and Sunday as weak surface low drifts
northeast off Cape Cod. Weak over-running pattern will gradually
diminish Saturday night as forcing weakens over the area. Moist
onshore flow will keep low clouds across much of the region
overnight along with scattered showers and areas of drizzle. Lows
will range through the 40s to near 50.
Upper low will begin to fill as it drifts east on Sunday. Onshore
flow will keep low clouds in place over the region through the
day. Will include low chance pops for scattered showers but expect
any activity to be light and spotty. High temps will be fairly
uniform across the region with most areas seeing lower to mid 60s.
Skies will remain mostly cloudy Sunday night and Monday as upper
low continues to fill as it drifts into New England. Can`t rule
out a stray shower or possibly a thunderstorm as cold pool aloft
shifts into south New Hampshire in the afternoon Monday. Highs
on Monday will once again top out in the lower to mid 60s.
Upper low will continue to fill Monday night as surface high
pressure builds in from the northeast. Increasing onshore
gradient will keep low clouds over the area for another night.
Expect diurnal showers to die out but coastal areas may see some
drizzle overnight. Lows will range from the mid 40s to mid 50s.
High pressure will continue to nose in from the northeast Tuesday
through Tuesday night finally bringing a break in the low clouds
as onshore flow is suppressed to the south of the region. After a
mostly cloudy start to the day expect partly sunny skies to
develop Tuesday with highs in the lower 60s.
High pressure will remain parked over the northeast Wednesday
through Thursday. Both days should feature mostly sunny skies
with highs in the lower to mid 60s.
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Short Term...Could see some MVFR to IFR cigs late tonight along
the coast and into KMHT/KCON, as flow shifts a little more
onshore, which may linger through Saturday morning.
Long Term...IFR/Lifr ceilings Saturday night through Monday
night. Improving to VFR on Tuesday.
Short Term...Persistent NE flow will fluctuate speeds a bit over
the 36 hours, but will generally run at or below SCA. This flow
will keep seas at or above 5 ft south of Casco Bay at least thru
Long Term...SCA`s may be needed Tuesday.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ150-
Small Craft Advisory until 6 AM EDT Saturday for ANZ154.