Area Forecast Discussion
Issued by NWS Portland, ME-- Highlight Changed Discussion --
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FXUS61 KGYX 232340 AAB
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
740 PM EDT Sun Oct 23 2016
Tonight clearing occurs across most areas as the dry west flow
continues but slowly diminishes. The cool cyclonic flow will
continue through midweek. By the end of the week another upper
trough will approach and move through the area with more unsettled
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --Update...Minor changes to the forecast based on latest
observational trends. Winds are starting to decrease and become
less gusty with time...and will continue that trend thru tonight.
Across the Ern Great Lakes a s/wv trof is quickly moving thru the
Wly flow...and will bring some light precip to the region
overnight. At this time that forcing looks to center over Srn New
England...with just an increase in cloud cover expected across Srn
NH. The trof passage will reinvigorate upslope clouds over Nrn
parts of the forecast area though.
Previous discussion...Clearing will gradually continue with
upslope snow showers continuing for a few more hours over the
west, northwest facing higher terrain. Cold air has arrived with
mins expected in the 20s overnight in the mountains.
Some clouds may spill into southern sections late tonight as a
short wave rotates through the base of the trough. There is a
small chance for showers, mainly in southern NH and southern York
County during the late night hours.
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.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Clouds may continue over southern section early before the short
wave quickly exits to our east. However, there will be a
reinforcing shot of cold air advection during the day. This will
allow for scattered upslope snow showers in the mountains and
additional cloud cover over northern and central sections.
The nearby presence of the upper level low will allow for a
continuation of chilly and windy conditions Monday night. Plenty
of cloudiness is expected outside the downslope areas with
scattered snow showers continuing.
Sufficient wind field Monday night to prevent frost along coastal
York and Rockingham counties.
.LONG TERM /TUESDAY THROUGH SUNDAY/...
The models remain in decent agreement on the longwave pattern
through late next week. The upper trough initially over the
northeast CONUS will gradually lift out into the maritimes for the
second half of the work week. An upper ridge will briefly
traverse the region Thursday. By early Friday...shortwave energy
will approach from the Great Lakes and eventually carve out
another upper trough over the eastern CONUS as we head into next
weekend. Overall...the upper pattern will support temperatures
near or slightly below average for the period. In the
dailies...low pressure surface and aloft over eastern Canada will
provide cool unsettled weather in cyclonic flow...with the most
persistent clouds and precipitation across the higher terrain. By
Wednesday night...clearing and cold as heights begin to rise with
arrival of high pressure. Thursday looks to be the pick of the
week with a sunny start as the ridge crests across the area.
Clouds will be on the increase during the afternoon from west-to-
east ahead of our next disturbance approaching from the Great
Lakes. We`ll see light overrunning precipitation arrive Thursday
night. The forecast thermal properties across the higher terrain
suggest it could begin as some wet snow and sleet before
transitioning to plain rain. Onshore flow and a slow-moving
frontal system promise a damp cool day to round out the workweek.
While the numericals continue to diverge on shortwave timing and
strength for the upcoming weekend...proximity of the longwave
trough supports a cool and unsettled weekend for the forecast
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Short Term...VFR conditions expected in all southern and downslope
areas this evening, while in the mountains mvfr conditions are
expected in scattered rain and snow showers. Conditions will
improve to VFR in the mountains overnight. All areas will be VFR
on Monday and Monday night.
Tue - Wed...Areas of MVFR psb mainly in mtn -shra/-shsn.
Tues...Daytime NW sfc wnd gusting to 25 kt.
Short Term...A persistent West flow will keep Gales over the
outer waters into tonight. Strong SCA conditions are expected in
the bays through tonight. On Monday the west gradient winds will
continue but will not be as strong. A SCA for the outer waters on
Monday will likely be needed while in the bays, conditions should
remain just below criteria.
Tue - Wed...Small Craft conditions are likely.
MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ151-153.
Gale Warning until 6 AM EDT Monday for ANZ150-152-154.