-- Discussion containing changed information from previous version are highlighted. --
418
FXUS61 KBTV 221134
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
734 AM EDT Sat Jul 22 2017

.SYNOPSIS...
As a weak cold front moves southward from Quebec and through
the North Country this afternoon, an isolated shower or
thunderstorm is possible across central and southern areas,
otherwise dry conditions are expected through the weekend as
high pressure settles overhead. An upper level disturbance
approaching from the Great Lakes will bring our next chance for
widespread precipitation, with periods of showers expected
Sunday night through Monday night.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 339 AM EDT Saturday...Mainly dry conditions are expected
across the North Country for the next 36 hours. A weak cold
front currently draped across southern Ontario and Quebec will
be dropping through the region today, and may provide enough
support for a few isolated showers and/or thunderstorms across
central and southern areas this afternoon, but coverage will be
very limited such as we`ve seen the past 2 days so don`t plan on
canceling any outdoor plans on that account. Highs will be
slightly cooler than the past few days, but still top out in the
upper 70s to mid 80s.

Behind the front, high pressure will settle over the region for
tonight with afternoon cumulus clouds dissipating to clear
skies and a seasonally chilly night on tap as 925-850mb temps
fall into the +10-15C range. Lows will fall into the 50s
areawide, with a few upper 40s likely in the colder hollows of
the Adirondacks and Northeast Kingdom. Fog will also be a good
bet in the climo favored river valleys.

Sunday appears to remain dry as well as our next system looks
delayed enough to keep precipitation out of the area through the
daylight hours. We`ve offered some chance PoPs in the late
afternoon and evening, but overall expect precip to hold off
with clouds increasing through the day and temps slightly below
normal in the mid to upper 70s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 339 AM EDT Saturday...A seasonably cool and rather
showery/wet period remains in the cards during the Sunday night
and Monday time frame. This morning`s model output continues to
advertise a digging shortwave trough will track east-southeast
into our area from southern Canada. This feature will separate a
much cooler continental airmass to our northeast from more
summery/humid weather to our south. Good QG forcing combined
with a PWAT bubble of near 1.5 inches supports widespread
showers arriving by Sunday evening across our western counties
and across the remainder of the area into the overnight hours
into Monday. Fairly decent lapse rates aloft also support the
idea of embedded non-severe thunderstorms, a few of which could
produce locally heavy downpours. The associated rain shield may
also tend to pivot across our area per the mean track of the
system which may act to focus heavier pockets of rainfall. Given
these factors WPC has included our area in a marginal risk for
flash flooding Sunday night/Monday morning. However, signals
remain too mixed in this forecaster`s opinion to feel overly
confident about the threat at this point so we`ll continue to
monitor over the next 48 hours. With the showers and an
abundance of clouds temperatures will trend on the cool side by
late July standards, with lows in the 50s to around 60 Sunday
night and corresponding highs on Monday mainly in the 60s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 339 AM EDT Saturday...Widespread showers then continue
Monday night with pockets of embedded thunder possible early
before tapering off during Tuesday as the shortwave energy
bundle exits east. Again, a few heavier downpours will be
possible, but the flash flood threat, at least at this point
remains on the lower side.

After a brief break on Wednesday with fair weather a weak high
pressure, a more distinct surface front will sweep into the
region Wednesday night into Thursday with a renewed shower and
thunder threat. A few of the storms could trend strong on
Thursday, but plenty of time to assess that threat over the
course of the next 5 days. After continued seasonably cool
weather Monday night into Tuesday, temperatures trend warmer
toward the middle and later portions of next week.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Through 12Z Sunday...Mainly VFR conditions are expected through
the period. SCT-BKN cirrus deck around 20kft will continue to
stream over the area today with some diurnal 060-090 cumulus
developing from mid-day onward. Weak frontal boundary dropping
through the area may provide an isolated shower or storm across
central/southern Vermont through the evening, but too difficult
to pinpoint hitting a terminal at this time. After 00Z, skies
trend back to FEW-SKC with the potential for IFR fog at KMPV and
KSLK after 06Z.

Outlook...

Sunday: VFR. Slight Chance SHRA.
Sunday Night: VFR. Likely SHRA.
Monday: VFR/MVFR. Likely SHRA...Chance TSRA.
Monday Night: VFR/MVFR. Chance SHRA...Slight Chance TSRA.
Tuesday: VFR. Chance SHRA.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...Lahiff
NEAR TERM...Lahiff
SHORT TERM...JMG
LONG TERM...JMG
AVIATION...Lahiff