Area Forecast Discussion
Issued by NWS Burlington, VT-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBTV 270730
Area Forecast Discussion
National Weather Service Burlington VT
330 AM EDT Sat Aug 27 2016
Fair and seasonably warm weather will prevail across the region into
Sunday as high pressure dominates the sensible weather pattern. The
next chance for scattered showers will occur by later Sunday into
Sunday evening as a weak front crosses the area. Behind this system
a return to fair and dry weather is expected for early next week.
.NEAR TERM /THROUGH TONIGHT/...
As of 102 AM EDT Saturday...Overall forecast in good shape with
just some minor tweaks to sky cover based on mid level clouds
moving into the northern third of the area. Otherwise no other
changes needed at this time. Still looking at some fog developing
during the early morning hours. Temperatures generally a blend of
bias-corrected model output offering overnight lows in the 50s to
near 60 and highs on Saturday from 78 to 85 or so under moderate
humidity levels. Winds light.
.SHORT TERM /SUNDAY THROUGH MONDAY/...
As of 327 AM EDT Saturday...A strong mid/upper level ridge of high
pres centered over VA will slowly break down as northern stream
energy moves from the Great Lakes into the NE Conus. The flow
around this area of high pres will advect pw values between 1.50
and 1.75 inches across our region ahead of a surface cold front.
This available moisture...combined with modest upper level forcing
from 5h vort will produce scattered showers on Sunday Afternoon
into the overnight hours. Highest pops will be across northern NY
between 18z-00z Sunday...but shift southeast into most of VT after
00z...as boundary crosses our region. Instability parameters show
a modest axis of surface based CAPE values between 500-1000 J/kg
between 21-00z Sunday...with greatest values located over northern
NY. Have included the mention of scattered thunderstorms...but not
heavy rain...as dynamics are limited and surface convergence is
weak. Temps on Sunday will be tricky as progged 850mb temps are
between 14-16c...supporting highs well into the 80s...but with
clouds and precip...expecting readings in the mid 70s mountains to
lower 80s valleys...with a few mid 80s near VSF. Humidity levels
will be increasing throughout the day...as dewpoints climb into
By Monday surface boundary is located just east of our cwa...with
any lingering showers quickly ending as much drier air advects
into the region. Progged pw values fall below 1.0 with moderate
cold air advection on breezy northwest winds. 850mb temps cool 4
to 6 degrees by 12z monday with highs mainly in the 70s
anticipated. will mention low chc pops in the morning for eastern
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 327 AM EDT Saturday...a cool night is expected on monday
night with surface high pressure located over northern NY and
building heights aloft. This will produce calm winds and clear
skies with temps ranging from the upper 30s/lower 40s to upper
40s/mid 50s warmer valleys.
On Tuesday...surface high quickly shifts into the Gulf of
Maine...as return flow develops ahead of approaching boundary.
Some uncertainty on amount of low level moisture return before
front arrives and overall instability on Tuesday afternoon. Pw`s
climb to 1.50...with weak ribbon of CAPE around 500 J/kg. Will
mention chance pops after 00z Wednesday with schc for
thunder...as instability is limited. If front is earlier and
greater instability develops from afternoon heating...then
a greater coverage and intensity of storms will be
possible...given upper level dynamics and associated jet.
Strong low level cold air advection follows boundary on Thursday
into Friday with 850mb temps falling between 2 and 4c. This low
level thermal profiles supports temps dropping back to below
normal by Thursday with highs mainly in the 60s to lower 70s and
lows in the 40s to mid 50s. Expect mainly terrain driven showers
on Thursday into Friday associated with upslope flow and some mid
level moisture. Will mention schc/low chc pops for the mountains
of NY into northern VT...based on position of closed 5h trof and
.AVIATION /07Z Saturday THROUGH Wednesday/...
Through 06Z Sunday...Overall looking at VFR conditions through the
period with just a minor exception. The potential for low clouds
and fog will exist at KSLK and KMPV between 09z and 13z...which
would result in IFR to VLIFR conditions. Area of mid level clouds
currently moving across the area may be a limiting factor to the
development of the low clouds and fog...thus there is only the
potential versus definitive that these conditions will occur.
Otherwise looking at some shallow cumulus over the higher terrain
later this morning and afternoon with high clouds...above 20,000
feet moving in after 00z. Winds will generally be under 10 knots
through the period.
Outlook 06Z Sunday through Wednesday...
06Z Sunday through Wednesday...mainly VFR through the period with
high pressure. Two main threat periods for scattered showers and
brief MVFR conditions - Sunday afternoon/evening, then again
Tuesday afternoon/evening with weak trough passages.