Area Forecast Discussion
Issued by NWS Portland, ME
FXUS61 KGYX 221538
Area Forecast Discussion
National Weather Service Gray ME
1138 AM EDT Sat Oct 22 2016
A slow moving low pressure system will move across central and
northern New England today allowing scattered showers. Later today
and tonight the low will gradually lift north into Canada. On the
backside of this system...colder air will arrive on gusty
northwest winds for the latter part of the weekend and early next
week. Some accumulating snow will be possible in the mountains
Saturday night into Sunday night. A large Canadian high pressure
system will then dominate the region through midweek next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Very heavy rainfall last night led to many locations receiving 2-4
inches of rain with locally higher amounts in the 5-6 inch range.
Showers, which were limited this morning thanks to the presence
of the dry slot associated with an area of low pressure developing
in the Gulf of Maine are now beginning to fill back in. Upper
level low continues to meander east with showers now breaking out
over MA/RI/CT per latest radar imagery. Will up pops for the rest
of today and into this evening into likely or categorical. Patchy
drizzle and fog to continue as well today.
Temps are near their forecast highs and will not budge much this
afternoon as showers and colder air begins to enter the forecast
Models show the developing surface and upper low to
move north across the region today creating instability showers.
The heavy rains that were in excess of 3 inches over some areas
from the system overnight, has moved off to the east so only
additional light amounts of showers are expected today. There is
plenty of low level moisture that will linger through the day due
to a lack of ventilation due to the center of the system passing
overhead today. This will mean, aside from any showers, a cloudy
day can be expected. Used a blend of models for max temp forecast
today and RFC qpf forecast.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
The center of the deep surface/upper low moves north into Quebec
tonight and in its wake a strong westerly pressure gradient will
develop. Strong cold air advection can be expected with this
system later tonight and Sunday. The combination of the strong
cyclonic pressure gradient and cold air advection will allow winds
winds to become strong and gusty Sunday. Temperatures will be cold
enough across the mountains to allow the instability showers in
the mountains to turn to snow showers with some light snow
accumulations possible. Elsewhere in the downsloping areas
conditions should remain dry.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The 500mb pattern in the extended features some flexible
omega blocking across NOAM and adjacent oceans to the east and
west. Over the the long range period the pattern will tend toward
troughing, but will see some ridges moving through. Overall, the
mean troughing should keeps temps below normal to normal through
We`ll start off with the closed low in the vicinity of the
Canadian maritimes Monday and Tuesday and this should provide
breezy conditions, showers in the mountains, and a a secondary
surge of cold air as a wave moves through Mon night. Highs Sunday
night through Tue will be in the 40s to around 50 /perhaps a
little warmer on Monday/. Lows will range form 30 to 40 both
nights. The upslope showers in the mountains will likely falls as
snow at times, but any accums should be limited to areas above
2000 feet, and these will be light.
Sfc high builds in on Wed, so we`ll finally see a break in the
breezy conditions, but this will limit any mixing effects, and
highs will once again be in the 40s to near 50. Models begin to
differ significantly by late Thursday with Euro bringing a weak
low and trailing cold front and the GFS remains dry. Either way
should see temps warm a some at the end of the week.
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
Short Term...IFR/LIFR conditions early this morning in areas of
fog and stratus and also showers across the Maine portions.
Conditions through the rest of the day will remain primarily IFR
over most areas. Tonight conditions will improve to mvfr and then
vfr as winds shift to the west as the system exits. Vfr conditions
are expected Sunday although MVFR in the mountains. Gusty west
winds are expected to develop later tonight and especially Sunday.
Long Term...Mainly VFR Sun night through Wed, except at KHIE which
could see tempo flight restrictions in low cigs and SHRASN Sun
night into Mon night.
Short Term...SCA conditions will continue today mostly in the form
of higher seas since will slack off as the center of low pressure
passes over the waters this afternoon. Eventually CAA developing
on the backside will increase winds to gale force on the outer
waters tonight through Sunday so a Gale warning had been issued
for the outer waters. In the bays a SCA will continue tonight and
Long Term...Persistent W to NW flow will keep an extended period
of SCA winds going right into Tuesday at least. Gales may persist
into Sun night, and could briefly return Mon night into early Tue.
MARINE...Small Craft Advisory until 7 PM EDT Sunday for ANZ151-153.
Small Craft Advisory until 8 PM EDT this evening for ANZ150-
Gale Warning from 8 PM this evening to 7 PM EDT Sunday for