Area Forecast Discussion
Issued by NWS Burlington, VT-- Remove Highlighting --
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FXUS61 KBTV 251432
Area Forecast Discussion
National Weather Service Burlington VT
1032 AM EDT Sun Sep 25 2016
Tranquil early fall weather will persist through Monday, as a
large area of Canadian high pressure crosses the region. The crisp
air mass will bring patchy frost in spots this morning, and again
on Sunday morning, and cool daytime temperatures with Sunday`s
highs in the upper 50s to lower 60s. Developing south winds will
allow for moderating temperatures on Monday, with high
temperatures reaching the mid to upper 60s in most valley
locations. A frontal system approaching from the west will bring
our next rainfall event Monday night into Tuesday.
.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --As of 1030 AM EDT Sunday...Previous forecast is in good shape,
though did opt to update sky cover a bit for eastern Vermont where
cyclonic flow from an exiting upper trough continues to dominate
and some scattered to numerous cumulus clouds have developed this
morning. These will likely persist through most of the day here,
while eastward skies will be mainly clear. Temps on track to top
out in the mid 50s to low 60s so no changes there. Enjoy!
Previous discussion from 333 AM EDT Sunday...Chilly start this
morning with local readings below freezing in the Adirondacks and
the colder sheltered valleys of Vermont`s Northeast Kingdom. At
07Z, temperatures ranged from 28F at KSLK, 30F at Lake Placid, and
32F at Island Pond. Frost advisory and freeze warning (Essex Co.
VT) continue thru 12Z this morning. Also anticipating some patchy
fog in the favored river valleys of central/ern VT...this should
dissipate by 13Z or so, lasting longest in the CT river valley.
Large Canadian high pressure shifts slowly ewd from sern Ontario
into the North Country today, and crests over the region tonight.
Looking for mostly clear skies with a dry air mass in place and
large-scale subsidence. Some cyclonic flow aloft could bring a few
passing clouds to far nern VT through the day, but overall will
see sunny conditions. The 925-850mb temps are slightly cooler than
Saturday, and as a result, anticipate aftn highs a few degrees
cooler as well...generally upr 50s to lower 60s. Winds won`t be
quite as strong as Saturday, but will see an increase to around
10 mph from the Northwest late morning thru afternoon.
With the high pressure system overhead, better radiative cooling
conditions for tonight. Expecting lows a few degrees colder...upr
30s Champlain Valley, but low-mid 30s elsewhere (and locally 27F
at SLK). This will bring additional frost away from the immediate
vicinity of Lake Champlain. Once we get through current frost
event early this morning, will likely need additional frost/freeze
highlights for Sunday night as well.
Surface anticyclone shifts east of New England during Monday, and
winds shift into the S-SE across the region. Should see temps
rebound a bit...with aftn highs in the mid-upr 60s...except locally
in the lower 60s across ern VT. Anticipate some increasing mid and
upper level clouds later in the day from west to east as a large
closed low crosses the central Great Lakes, and associated sfc
cold front reaches far wrn NY. Frontal rain showers should hold
off until Monday night.
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.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
As of 422 AM EDT Sunday...A cold front will move east from the
Great lakes Monday night with rain showers developing over
northern New York. Expecting this rain shower activity to move
into Vermont mainly after 06Z Tuesday. Have gone with likely or
categorical pops. Models showing mid level dry slot to move into
the region early Tuesday morning over northern New York, and
across Vermont Tuesday morning. Expecting rain shower activity to
be over across the region by 18Z Tuesday, as mid level dry slot
will be over the region. The only exception to this will be over
the Saint Lawrence valley where models hinting at moisture moving
northeast from Lake Ontario, so have kept in slight chance pops
for showers there.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 422 AM EDT Sunday...Models have a closed upper low over the
western Great Lakes Tuesday night, but GFS and ECMWF have vastly
different solutions as to the forecast track of this upper closed
low through Saturday. This leads to a rather low confidence
forecast, especially from Thursday through Saturday. Have gone
with a dry forecast across the region Tuesday night through
Wednesday night, as GFS and ECMWF in fairly good agreement on
this. ECMWF takes this closed upper low over the western Great
Lakes and moves it southward to the southern Appalachians and then
retrogrades it back to the western Ohio valley by early Friday
night, as an upper ridge builds northwest from the Atlantic across
New England and northern New York. The GFS model takes this upper
low over the western Great Lakes Tuesday night and moves it
southeast across the Ohio valley and into southern New England by
early Friday night. The ECMWF suggests a mainly dry forecast
Thursday and Friday across the region, while the GFS model hints
at a showery forecast from Thursday through Saturday. Have opted
to stay with the superblend pops from Thursday through Saturday
and have low chance pops for showers during this period. Given the
significant differences in the location of the closed upper low
during the period from the ECMWF and GFS models, forecaster
confidence is low through the long term period.
.AVIATION /15Z Sunday THROUGH Thursday/...
-- Changed Discussion --Through 12Z Monday...Mainly VFR/SKC. Northwest around 10 knots
after 14z and persist thru the remainder of the daylight hrs.
Light and variable winds return after 00Z Monday and unlike last
night...no low level jet thus despite another day removed from
rain better chance of valley fog thus lifr at kslk and kmpv aft
06z mon with IFR possible at Krut.
Outlook 12z Monday through Thursday...
12z Mon - 00z Tue: Mainly VFR.
00z Tue - 00z Wed: VFR trending to a mix of VFR/MVFR in scattered showers.
00z Wed - 00z Fri: Mainly VFR with isolated MVFR cigs.
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