Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KGYX 141229
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
729 AM EST Sat Jan 14 2017

.SYNOPSIS...
High pressure shifts east and weakens through today, allowing a
weak cold front to move through the area early Sunday. It will
not produce more than some clouds and a few flurries in the
mountains. High pressure will build in behind the front Sunday
afternoon through Monday. The high pressure shifts east on Tuesday
and will allow a southwest flow of warmer air into the region.
Weak low pressure crosses the region mid-week and will bring rain
to coastal areas and mixed precipitation inland Tuesday night into
Wednesday.

&&

.NEAR TERM /TODAY/...
730AM UPDATE...
Have updated the forecast to include latest observations from
early this morning which should capture most of the morning low
temperatures. Light winds over the last couple of hours allowed a
steep drop off at several locations, but we will see temperatures
warm into the teens and 20s today.

ORIGINAL DISCUSSION...
Cold high pressure moves over the area today. This will bring very
light winds and a mostly clear sky, although temperatures will
only warm into the teens and 20s.

&&

.SHORT TERM /TONIGHT AND SUNDAY/...
High pressure begins to shift offshore tonight, with a shortwave
trough in Canada sending a weak front toward the area. Given the
very dry air ahead of this front, do not expect much to occur as
it arrives other than maybe some upslope clouds in the mountains.
Maybe a flurry is possible as well. Meanwhile, the coastal plain
should stay mostly clear, aside from some early evening high
clouds associated with weak low pressure passing well south of New
England. With a good period of clear, calm conditions south of the
mountains, we will likely see some good radiational cooling in
these spots. Have lowered temperatures a few degrees from guidance
in this area, while keeping things a touch warmer in the mountains
where clouds may prevent good cooling.

Will see a little more wind on Sunday as high pressure to our west
builds into our area. Temperatures will be a couple of degrees
warmer than on Saturday, generally in the 20s to low 30s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Chance of high impact weather: Low. A mix of snow and freezing
rain could cause some travel problems inland Tuesday night into
Wednesday morning.

Models continue to show split flow at 500 mb near the west coast
at the start of the extended, which will allow Pacific air to
dominate the weather across the lower 48 and southern Canada,
which will mean mostly above normal temps right through the week.
This does not mean we will not some see some wintry precip, as a
several weak 500 mb waves move through during the middle of the
week. The trend toward the end of the week and thru next weekend
will be to more amplified flow with a higher wave number, and
potential blocking setting up over the central CONUS.

Sunday night will be dry, and should be fairly cold as well. Weak
500 mb troughing could prevent full radiational cooling /which is
possible given surface high centered over forecast area/, as it
spreads cirrus shield across northern and eastern zones
overnight, but lows range in the single digits above and below
zero.

Monday will see surface high shift slowly east, with westerly 850
mb flow bringing some warmer air aloft. Light winds through most
of the day will prevent full mixing, but highs should push up into
the mid 20s N to mid 30s S with partly to mostly sunny skies.
Monday will not be as cold as previous nights, with cirrus moving
in late and increasing SW flow. Lows will range form 10-15 in the
N to the lows 20s in the S.

The next system could bring precip into southern and western
zones Tuesday afternoon, as clouds increase and S flow picks up
as well. Should warm coastal areas and southern NH into the upper
30s to low 40s, but inland areas may be limited to 30-35 for their
highs. Best chance for precip will be Tuesday night into Wednesday
with this system. P-type forecast is tricky at this point, as
split flow is generating wavy pattern across the CONUS. May see 2
separate waves move through, at least according to 00Z Euro, which
holds onto stronger and more persistent surface high lingering
over the maritimes through Wednesday. This would mean cold air
damming and better likelihood of frozen or freezing precip inland.
GFS organizes system into one trough and pushes the high out
faster. Either way, some SN or FZRA can be expected Tuesday night
inland, and may linger into Wednesday morning in northern ME
zones. Precip should change to rain everywhere by Wednesday
afternoon, and may bring some slightly colder air into the
mountains on Thursday. But overall there`s not a lot of cold air
behind this mid-week system, and temps should run above normal
into next weekend, even if there is low confidence regarding
precip timing late in the week and into next weekend.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Light winds and clear sky expected today through
Sunday. The only exception could be a period of MVFR ceilings
north of the mountains late tonight.

Long Term...VFR through early Tuesday afternoon. MVFR to IFR late
Tuesday and Tuesday evening with IFR expected late Tuesday night
and Wednesday. RA on the coast and in southern NH and SN/FZRA
Tuesday night inland going over to RA Wednesday. Could see
lingering MVFR conditions through Wednesday night.

&&

.MARINE...
Short Term...Should see a brief period of light winds over the
waters today as high pressure moves in. Another high moves in from
the west on Sunday and could bring a bit stronger northwest winds
early on Sunday, possibly reaching advisory levels again.

Long Term...Winds seas remain below SCA levels Sunday night trough
Tuesday but could approach SCA briefly on Wednesday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Wind Chill Advisory until 10 AM EST this morning for
     MEZ007>009.
NH...Wind Chill Advisory until 10 AM EST this morning for NHZ001.
MARINE...None.

&&

$$

NEAR TERM...Kimble
SHORT TERM...Kimble
LONG TERM...Cempa


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.