509
FXUS61 KBTV 221420
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1020 AM EDT Mon May 22 2017

.SYNOPSIS...
Light rain showers and overcast skies will linger today, as a
trough of low pressure exits the region. Cool temperatures today
will moderate toward normal as a weak ridge of high pressure
builds in on Tuesday and Wednesday. Rain will enter the
forecast toward the end of the week with an area of low pressure
moving through the northeast Thursday and Friday, resulting in
relatively cool temperatures.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 1009 AM EDT Monday...Secondary surface trough axis
shifting ewd across w-central NY/PA is associated with an
additional band of shower activity...tracking ewd across the nrn
Adirondacks and St. Lawrence valley at 14Z. Have made some
adjustments to PoPs to account for slightly earlier arrival of
this trough and associated shower activity. Not expecting
anything too significant...with an additional 0.01 - 0.10"
rainfall on top of the 0.3-0.5" that generally fell during the
overnight hours.

Will see some gradual mid-level drying this afternoon (above
750mb) with WSWLY flow aloft, but pronounced low-level
inversion should continue to hold low stratus in areawide with
overcast skies and cool temperatures. Afternoon highs only
expected to range from the lower 50s east of the Green Mtns, to
near 60F at BTV, and upr 50s to lower 60s across nrn NY. The
KCXX vad wind profile still indicates 25-30kt flow at 2-3kft
AGL. Won`t fully see these winds at low elevations due to
stability, but occasional gusts to 20-25 mph are possible thru
this aftn. Expect winds remaining 20-25kts over the broad
portion of Lake Champlain, and the Lake Wind Advisory continues
there.

Tonight through Tuesday a weak surface ridge builds into the
region. Lowering inversion and light surface winds, along with
moist ground from recent rain will promote fog formation in the
usual areas. During this time flow aloft remains southwesterly,
and low pressure over the Great Lakes will ride through the 500
mb ridge, suppressing the ridge & shifting it east. The low
passes well enough north that the surface ridge will win out
with no rain during this time, but will still be quite a few
clouds around. Tuesday about 10 degree warmer than monday with
highs in the 60s/near 70.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 349 AM EDT Monday...Weak ridge both aloft and at the
surface build across our cwa on Weds...ahead of developing full
latitude trof over the MS River Valley. This ridging should keep
moisture and precip associated with weak low pres riding along
the eastern seaboard to our east on Tuesday Night into
Weds...with mainly a dry forecast anticipated. Progged 850mb
temps between 9-11c...support highs mainly in the mid/upper 60s
mountains to mid 70s warmer valleys on Weds. Mid/upper level
closed cyclonic circulation over the MS River Valley slowly
moves eastward toward the OH Valley on Weds Night....with
southerly winds and increasing clouds. Given the slow movement
of the closed system from the flow aloft...will keep Weds Night
dry with temps mainly in the 50s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 349 AM EDT Monday...A period of unsettled weather likely
Thursday into Friday...with occasional rain showers and breezy
southerly winds. Closed mid/upper level circulation will slowly
track toward the Mid Atlantic States as 998mb low pres is
located near Binghamton, NY by 00z Friday. The combination of
strong southerly flow between 850 and 500mb will help advect
deeper layer moisture into our cwa...with PWS >1.0 developing.
The initial warm air advection surge will produce a period of
showers on Thursday with qpf values generally between 0.10 and
0.25. Some downslope shadowing/enhancement on southeast 925mb to
850mb of 30 to 40 knots is likely. Meanwhile...strong 5h energy
rounds mid/upper level trof base on Thursday Night...with
system becoming vertically stacked over southern New England by
Friday. The combination of easterly 925mb to 700mb flow and
favorable energy aloft will produce another round of light to
moderate rainfall on THursday night into Friday. Depending upon
exact track of low pres...will determine placement of heaviest
qpf...but nose of 850mb jet would suggest central/eastern VT.
Thinking additional qpf will range between 0.25 western areas to
0.75 central/eastern VT...with around 0.50 in the CPV. Will
mention likely pops for this period.

Friday night into Saturday...system will slowly lift northeast with
mainly light terrain driven/upslope showers persisting into
Saturday. Difficult to time individual pieces of s/w energy in the
northwest flow aloft...but thinking lingering mid level moisture and
favorable upslope flow...some rain shower activity is possible into
Saturday.

Sunday...Still some uncertainty on Sunday with timing of warm front
feature and associated potential for showers. At this time...Sunday
Morning looks dry...with a chance of showers increasing during the
afternoon hours...along with increasing humidity levels. Any precip
looks to be light and generally under 0.20".

For temps...mainly the mid 60s to mid 70s For Thursday... but only
mid/upper 50s to mid 60s with widespread clouds/rain showers for
Friday with coolest values across the eastern mountains. Weekend
temps mainly in the mid 60s to mid 70s for highs and lows mid 40s to
mid 50s. No major heat anticipated with general mid/upper level trof
across the NE Conus this upcoming weekend.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
Through 12Z Tuesday...Rain has ended and 12Z TAFs reflect no
precip for first few hours, then a few hours of 4sm -shra or
vcsh mid day in northern New York terminals, and early-mid
afternoon in Vermont. MVFR cigs at KMSS/KSLK at 11z to spread
east during the day. Cigs to lower through the day but remain
MVFR, bottoming out at OVC015 00-06z. Some improvement to VFR
cigs after 06z west to east. Exception is in areas of fog
formation, primarily KSLK/KMPV after 06z where OVC008 forecast
with 1SM BR. Any fog to dissipate shortly after 12z Tuesday.

Strong south wind from the south around 12-15 knots with gusts
to 20-25 knots this morning, tapering off after 21z.

Outlook...

Tuesday: VFR. Patchy morning FG.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Slight Chance SHRA.
Wednesday Night: VFR. Chance SHRA.
Thursday: VFR. Breezy. Likely SHRA.
Thursday Night: VFR/MVFR. Likely RA.
Friday: MVFR. Likely RA.

&&

.MARINE...
As of 425 am EDT Monday...A Lake Wind Advisory is in effect
today to early evening. Winds have come up sharply on the lake
with 4 am EDT obs gusting to 31 knots. Air temperature has dropped to
near water temperature and aided in mixing stronger winds down.
Strongest wind, 20-30 knots, before noon but will remain above
wind advisory threshold at 15-25 knots until this evening.
Waves building to 2-4 feet, with highest waves are expected
across the northern portion of the broad lake south of Grand
Isle.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Hanson
NEAR TERM...Banacos/Hanson
SHORT TERM...Taber
LONG TERM...Taber
AVIATION...Hanson
MARINE...Team BTV