Area Forecast Discussion Issued by NWS Portland, ME
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FXUS61 KGYX 131447
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
1047 AM EDT Wed Mar 13 2024
.SYNOPSIS...
Warm and mainly dry today and Thursday. Waves of low pressure
will cross New England Thursday night and Friday bringing snow
showers to the mountains and rain showers south of the
mountains. Saturday looks to be break in systems before a trough
develops over the Great Lakes and additional systems approach
Sunday through early next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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1045 AM Update...Going forecast is in good shape with only minor
tweaks to T/Tds and sky cover. A weak wave approaching from the
west has resulted in some radar echoes over Upstate NY with
these echoes weakening as they move into Vermont and surface obs
suggesting precipitation is not reaching the ground. Will
continue to monitor trends with these weak returns, but for now
have left the forecast area dry through the rest of today.
Previously...
Weak 500 MB ridge build in this morning, with weak wave trying
to crash into late today and overnight. Will see cirrus move in
from the W this afternoon, with probably some mid level clouds
come in late as well, although I think for sky we move from
sunny this morning to p/sunny mid to late afternoon. The HRRR is
only the mesoscale to show some showers move in across the
central and srn CWA this afternoon, with all the others,
including ensembles like the HREF/SREF keeping the bulk of any
shower in the N very late today and overnight, so this is the
forecast I’ve gone with. Winds become very light today allowing
sea breeze to develop this afternoon, so maxes end ranging from
the mid upper 40s in the mtns, to the low 50s along the coast
and into interior western and central ME, and into the upper 50s
in interior S NH.-- End Changed Discussion --
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.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Those isolated showers move through the mtns and the N
overnight, and could be RA or SN or a mix, but likely snow
across the higher terrain, although won;t be enough to worry
much about accums. Give what will amount to a BKN-OVC at times
in many spots, and despite light winds, decoupling will not be
widespread, but some late rad cooling may occur late over the
srn half of NH, where some clearing may occur before sunrise.
Lows range from around 30 in the mtns and the colder spots to
the mid 30s.
Although any lower to mid level clouds clear out in the morning
there will be a lot of cirrus around on Thursday, and will
start to thicken more in the afternoon ahead of the next system.
Once again light winds will be the rule with a sea breeze
developing again. It’ll probably be a few degrees warmer inland
areas of NH and SW ME, but similar maxes on the coast and
interior central ME, with highs 45-50 in the mtns, low to mid
50s on and near the coast, and around 60 in interior S NH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Precipitation is expected to overspread the region Thursday night
(generally after midnight) into Friday morning as a wave of low
pressure rides along a stationary boundary. Temperature profiles
support mostly rain outside of the mountains, but should the
cooler NAM be onto something, light snow could be seen farther
south toward the lakes regions of NH/ME and over into the
Augusta region. This round of precip should shift east of the
area by the afternoon hours, but additional energy aloft may
yield additional light precipitation through the rest of the day
into the evening. Model guidance, including ensembles, is in
overall pretty good agreement with QPF being around 0.50" with
this system, maybe a little higher in a few areas.
Going into Friday night, low pressure will pull to the east away
from the area, and flow will switch to northwesterly as weak high
pressure builds in. This will keep a chance of upslope rain/snow
showers in across the north and mountains through Saturday with
generally dry but still party-mostly cloudy conditions elsewhere.
Max temps on Saturday will be mostly in the mid 40s to lower 50s.
The weather pattern stays unsettled from Sunday into early next
week with a broad upper low encompassing much of eastern
Canada, which will send multiple shortwaves through New England.
The first is expected Saturday night into Sunday which will
send a cold front through sometime during Sunday along with
another round of light precip (ensemble means favoring 0.25" to
0.50" QPF). The northern track of the low should keep p-type as
rain outside of the mountains, and while confidence is high
we`ll see precip Saturday night and/or Sunday, PoPs have still
been capped at 50-60% due to some discrepancies in timing.
For Monday and Tuesday of next week, low-level flow is expected to
become northwesterly, meaning a chance of upslope rain or snow
showers in the mountains, which could be enhanced at times as
additional shortwaves cross through. These waves could also
bring a few showers south of the mountains, but the chances will
be lower.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Although clouds move in late today and overnight,
cigs will remain at VFR through tonight and into Thursday. Winds
will be light as well.
Long Term...Low pressure will bring a round of precip Thursday
night through Friday in the form of mostly rain, but light snow
can`t be ruled out a AUG and HIE. Terminals can expect ceilings
to lower to MVFR to IFR through the overnight hours along with
reductions in visibility. Precipitation should come to an end
later in the day Friday or the early part of Friday night with
most sites returning to VFR by daybreak Saturday. The exception
as usual will be HIE, with MVFR ceilings prolonged through
Saturday along with a chance of a rain or snow shower. There may
be a shower elsewhere, but confidence is low at this time.
Another low pressure and frontal boundary could bring more
flight restrictions Saturday night and Sunday.
&&
.MARINE...
Short Term...Winds/seas now below SCA and then will continue
diminish through this morning. Winds stay light and seas remain
2 ft or less this afternoon through Thursday. Long Term...
Long Term...A weak area of low pressure will slide eastward across
the waters Thursday night into Friday, and it`s possible gusts could
reach SCA level out of the E/SE ahead of the low Friday morning
and again out of the north later in the day on Friday. Weak
high pressure keeps conditions below SCA levels on Saturday, but
southerly winds could exceed SCA levels on Sunday as a low
pressure and cold front approach and then cross the waters
later in the day. Low pressure is expected to remain generally
east or northeast of the waters early next week, promoting
offshore flow.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR TERM...Cempa/Schroeter
SHORT TERM...Cempa
LONG TERM...Combs