Area Forecast Discussion
Issued by NWS Burlington, VT-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBTV 280216
Area Forecast Discussion
National Weather Service Burlington VT
1016 PM EDT Thu Oct 27 2016
An upper level trough of low pressure will move across the region
tonight through Friday morning before exiting to our east Friday
afternoon. Widespread precipitation is expected tonight through
Friday morning before tapering off Friday afternoon. Temperatures
will remain below normal for this time of year on Friday and
continue right through the weekend. In addition...there will
continue to be the chance of showers on Saturday and Sunday.
.NEAR TERM /UNTIL 6 PM FRIDAY EVENING/...
-- Changed Discussion --As of 1011 PM EDT Thursday...Cooler temperatures near freezing or
1-2 degrees above hanging tough along and east of Green Mountains
and in the Adirondacks. Loaded in latest LAMP temperature guidance
that reflects the trend, and then also updated snow amounts based
on cooler temperatures. Max snow amounts remain the same over
higher terrain, however inch or less snowfall extends further east
and north in Vermont in the 00-06z time period. Temperatures
eventually do rise above freezing after midnight to change
remaining snow over to rain.
Surface low has moved to eastern Lake Ontario and will continue
to lift northeast up the St. Lawrence Valley. IR satellite loop
showing coldest cloud tops and enhanced precip lifted northeast,
with precip over the forecast area taking on a more showery
coverage pattern. We will begin to see cyclogenesis along the
southeast New England coast as the upper trough takes a more
Upper trough moves across the area on Friday. While exiting
dynamic support helps to decrease the areal coverage of
precipitation... northwest flow aloft develops and begins to
enhance orographic precipitation. This should keep accumulating
snows going over the higher terrain and generally rain showers at
the lower elevations with highs generally in the upper 30s to mid
-- End Changed Discussion --
.SHORT TERM /6 PM FRIDAY EVENING THROUGH SATURDAY NIGHT/...
As of 342 PM EDT Thursday...A weak ridge will build in Friday
night as northwest flow will gradually shift to southerly flow.
Low level RH (<850mb) will still be greater than 95% while the
northwest flow remains and so I anticipate light showers to remain
in the upslope areas on the western slopes of the Greens and
Adirondacks due to the orographic lift. These showers however will
gradually come to an end as the low level moisture dissipatesby
Even with the loss of low level moisture there should still be
ample in RH in the 700-500mb range which will lead to fairly
consistent cloud cover overnight. The cloud cover should keep
temps from bottoming out, and so the forecast is a blend of
available guidance trended a bit warmer than MOS even as the winds
A weak low pressure system passes north of the border on Saturday
and the lack of any significant forcing will lead to much of the
area seeing light precip but no significant accumulations of rain.
Due to us sitting in the warm sector boundary layer temps are
warm enough to just be all rain across the North Country.
Southerly warm air advection will persist and temps should warm
into the upper 40s to near 50s in the Champlain Valley. Overnight
lows will be well above normal due to the warm air advection that
will persist through the weekend.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 401 PM EDT Thursday... High pressure begins to build in
behind that upper level trough as it passes to the North. This
will lead to dry weather to begin the work week. The next
"feature" that will impact the North Country is a low pressure
system tracks up the through the Great Lakes towards James Bay
which does the unfortunate thing by brining a dry warm front
through the North country. So we will be looking at a gradual warm
up with temps moderating into the mid to upper 50s Tuesday into
Wednesday under continued southerly flow.
.AVIATION /02Z Friday THROUGH Tuesday/...
Through 00z Saturday...Mainly MVFR/IFR in rain and snow across the
region, with snow mainly over the higher elevations of the
Adirondacks and Green Mountains, mainly above 1000 feet above sea
level. Expecting precipitation to wind down across the region by
18Z Friday. Expecting mainly MVFR ceilings after 18Z Friday
through 00Z Saturday.
Outlook 00z Saturdaythrough Tuesday...A warm front feature
lifting across our taf sites on Saturday morning will shift the
winds to the southwest with some scattered showers
possible...especially MSS/SLK. Expecting mainly vfr conditions
with intervals of mvfr cigs possible across northern NY taf sites
on Saturday. Gusty southwest up to 35 knots are possible at MSS
with 30 knots expected at SLK/BTV on Saturday. Another wind shift
to the west/northwest will occur Sat Night into Sunday with
additional scattered showers. Drier conditions with vfr flight
conditions for Sunday afternoon into Monday.
As of 255 PM Thursday...Several bouts of strong winds and rough
conditions are expected on the lake the next few days. South/southeast
winds of 15 to 25 knots are expected through late evening, before
diminishing after midnight. During the day Friday, winds will
switch to the northwest and strengthen, with winds approaching 25
knots for the afternoon and early evening. Winds will diminish
Friday night, but then switch to southerly on Saturday morning.
Winds will quickly increase again to around 25 knots during the
mid-day hours. These strong and gusty winds will result in choppy
conditions out on the lake.