Area Forecast Discussion
Issued by NWS Burlington, VT
FXUS61 KBTV 281135
Area Forecast Discussion
National Weather Service Burlington VT
735 AM EDT Sun Aug 28 2016
The threat for showers and thunderstorms will increase across the
area this afternoon and evening as an upper level trough of low
pressure approaches from the west. Areas most likely to see the
showers and storms will be across the northern Adirondacks of New
York and the northern and central sections of Vermont. High
temperatures will remain above normal today. Some showers will
linger over the area Monday morning...but high pressure builds in
and brings drier air and seasonable temperatures.
.NEAR TERM /THROUGH TONIGHT/...
As of 652 AM EDT Sunday...Mid level moisture continues to move
across northern New York and the northern half of Vermont this
morning. There have been reports of sprinkles with these clouds
and have added to the forecast for the next couple of hours.
Otherwise...feel cloud cover will thin out mid-morning and allow
temperatures to warm and eventually reach the upper 70s to mid
80s. This combined with dew points rising into the 60 to 65 degree
range should help to create sufficient instability to enhance the
convective potential. As usual the models are too high on the dew
points and thus creating too much instability. Upper trough over
the Great Lakes region will lift northeast today and thus dynamic
support will be increasing over the area this afternoon. As trough
approaches...deep layer shear will be increasing but will not be
too strong. Feel enough ingredients exist for thunderstorms to
develop this afternoon and evening...but none of them are strong
enough to suggest storms become severe. Cannot rule out a strong
storm or two however with gusty winds and heavy downpours being
the main threats. Best potential for thunderstorms looks to be
across the northern Adirondacks and the northern and central
sections of Vermont.
For tonight...areal coverage of showers and storms will be
greatest during the evening hours...then quickly taper off after
midnight as instability and forcing diminish. Lows will generally
be in the 60s as plenty of low level moisture lingers over the
.SHORT TERM /MONDAY THROUGH TUESDAY/...
As of 309 AM EDT Sunday...Synoptic scale features show mid/upper
level trof across the NE CONUS on Monday with surface cold front
located over eastern New England at 12z. The combination of
additional 5h energy associated with trof and lingering leftover
moisture in low to mid level cold air advection pattern supports
the mention of chance pops on monday morning. Based on moisture
progs and upslope wind profiles...thinking any precip will be
terrain focused during the morning. Soundings show deep drying on
nw flow developing after 18z monday with skies becoming sunny.
Progged 850mb temps cool to 10c with 925mb temps around
16c...supporting mid 70s to lower 80s with northwest winds 5 to 15
mph. a great sleeping night expected on monday night with 1024mb
surface high pres overnight...providing us with clear skies...low
humidity values...and cool temps with light winds. Lows will range
from the 40s mountain valleys to mid 50s champlain valley by
tuesday morning...with light terrain winds and some patchy valley
fog. Surface high pressure with mostly sunny skies and developing
south winds is expected for Tuesday. Low level thermal profiles
warm a 1 or 2...supporting highs mid 70s to mid 80s depending upon
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 309 AM EDT Sunday...Overall pattern will feature a
transition from ridge across the mid atlantic to deepening
mid/upper level trof over the NE CONUS. This will result in below
normal temps by late week with mainly terrain focused precip
chances on Weds into Thurs associated with cold front and trof
development. QPF values will be light...with only chance pops
On Weds mid level moisture increases with pws approaching 1.50
inches ahead of northern stream trof and associated cold front.
Deep layer moisture is limited...but dynamics are rather strong
with trof development so will continue to mention chance pops aft
18z Weds into early Thurs morning. Instability is modest with
values generally< 500 j/kg...so kept just showers for now.
Additional short wave energy and some moisture associated with
secondary cold front impacts our region on Thurs. Areal coverage
and intensity of showers will be limited...and mainly confined to
the mountains with favorable upslope flow. The last in a series of
short waves will impact our region on Friday...while vort is
potent...moisture is lacking so maybe a few isolated
showers...especially northern mountains.
Temps ahead of cold front warm into the upper 70s to lower 80s
with south to southwest winds. progged 850 and 925mb temps cool 4
to 6 degrees by 18z thursday...supporting 60s mountains to mid 70s
warmer valleys. Additional cooling on brisk northwest winds occur
on friday with progged 850mb temps in the single digits...supporting
highs upper 50s to upper 60s/near 70f. Initially lows will be in
the upper 40s to lower 60s...but by Saturday morning patchy frost
is possible at slk and across the deeper valleys of the northeast
kingdom. Thinking lows will range from the l/m 30s to upper
40s...except mid 50s near lake champlain by early Saturday
morning. Average 1st frost at SLK is Sept 7th...so pretty close to
.AVIATION /12Z Sunday THROUGH Thursday/...
Through 12Z Monday...Overall much of the period through 18z will
experience VFR conditions. Mid level clouds with sprinkles will
move across the area through 14z before a period of generally
clear skies develops through early afternoon. This will allow the
atmosphere to destabilize and the potential for showers and
thunderstorms will increase between 19z and 02z with periods of
MVFR/IFR conditions in and near the showers and storms. After 02z
there will be widespread VFR/MVFR ceilings for the remainder of
the period. South to southwest winds will increase through the
morning with gusts in the 15 to 25 knot range before tapering off
Outlook 12Z Monday through Thursday...
12Z Monday through Thursday...mainly VFR through the period with
high pressure. Scattered showers and brief MVFR conditions
possible Tuesday afternoon/Wednesday with weak trough passages.
Winds will continue to increase out of the south today and reach
the 15 to 25 knot range this afternoon and evening. Thus a lake
wind advisory is in effect for this time period due to the
stronger winds and choppy waters. In addition...the potential for
thunderstorms will exist this afternoon and evening which will
have the potential to produce gusty winds and heavy downpours.