-- Discussion containing changed information from previous version are highlighted. --
813
FXUS61 KBTV 132334
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
734 PM EDT Mon May 13 2024

.SYNOPSIS...
An unsettled weather pattern will continue over the next couple of
days with several rounds of showers, with numerous showers and some
embedded thunderstorms expected tomorrow. Seasonable high
temperatures and mild overnight lows are expected for much of the
upcoming week.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...

-- Changed Discussion --
As of 733 PM EDT Monday...Forecast remains in good shape so
only made minor tweaks to bring it up to date with current obs.
Warm front is lifting north across NY state, helping to fuel a
few showers with a couple of cloud flashes detected by the GLM
product across eastern St Lawrence county. However, the latest
RAP mesoanalysis shows height rises across North Country. And
with a relatively stable environment as well as the loss of
diurnal heating, the expectation is that the showers for much of
this evening into the early overnight hours should be in the
form of showers with minimal to negligible risk for lightning.
Temperatures will be slow to fall, especially across northern NY
and the Champlain Valley due to persistent southerly winds.

PREVIOUS DISCUSSION...Light showers across the region have
brought little to no measurable precipitation this afternoon,
with only a few hundreths at most so far. As we head into the
evening, a frontal boundary will become stalled near the
International Border, with increased chances for showers and
some possible rumbles of thunder across northern New York
overnight due to increased elevated instability and stronger
forcing. Overnight lows will be on the mild side tonight, in the
50s, although spots east of the Greens will drop into the upper
40s.

Model soundings for tomorrow show tall and skinny CAPE profiles,
supporting the idea of some heavy downpours and embedded
thunderstorms tomorrow afternoon, with PWAT values in excess of an
inch. Current QPF amounts range from a few tenths to near an inch,
with localized higher amounts expected in any thunderstorms. The
latest CAM guidance suggests CAPE values between 500 to 1200 J/kg
across southern portions of the forecast area tomorrow, with
temperatures warming into the 70s. Meanwhile closer to the
International Border, temperatures will only warm into the upper
60s. There is still a little uncertainty regarding the instability
across the region tomorrow afternoon as lingering cloud cover will
limit surface heating. There is the potential for training storm
motions with any developing convection, which will need to be
monitored given the potential for heavier downpours. While
widespread severe is not currently anticipated, NCAR is showing a
non-zero threat for some severe weather and there will likely be
plenty of activity to monitor tomorrow afternoon. Shower activity
will dwindle heading into the evening with the lack of diurnal
heating, with overnight lows expected to be quite mild for this time
of year.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 402 PM EDT Monday...ANother round of showers is expected for
much of Wednesday as a cut off low becomes stuck over the Mid-
Atlantic region. This slow moving low pressure system is expected to
drape a warm frontal boundary across our forecast area which should
allow for shower activity to increase throughout the day on
Wednesday given modest heating under cloudy skies. Thermal profiles
have varied from run to run but it seems we will be looking at
closer to moist adiabatic lapse rates which in this case likely
won`t favor thunderstorms. Could a rumble of thunder occur?
Possibly, but most likely we should just see scattered to numerous
showers on Wednesday. The main focus on rainfall accumulations will
be across southern Vermont where we could see a quarter to maybe a
third of an inch of rain but lesser amounts as you get closer to the
International Border. Shower activity is expected to wane as we head
into Wednesday evening with the loss of daytime heating but a few
showers will likely continue through the overnight period.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 402 PM EDT Monday...Thursday had been looking drier for a while
but the latest guidance suggests it may not be as dry as we had been
thinking. The stall frontal boundary mentioned in the above section
will remain over the area on Thursday. We better heating due to
slightly less cloud cover, a resurgence of shower activity is
expected during the afternoon hours. It won`t be as widespread as
Wednesday but isolated to scattered showers could drop some light
rain throughout the day with thunderstorm potential again looking
rather meager. Friday, on the other hand, has trended a little drier
as the 12Z guidance is showing building 500 mb heights in response
to a deepening trough over the central US. Increasing subsidence is
expected to keep shower activity largely at bay although a few
diurnal showers cannot be ruled out.

Rain chances will increase throughout the day on Saturday as the
aforementioned trough slides eastward and we see a series of frontal
boundaries move through the region. With good fetch of Gulf of
Mexico moisture, we could see some heavy rain showers this weekend
but the details will be ironed out over the next several days. Those
with outdoor weekend plans are encourages to keep a close eye on the
forecast. This period of unsettled weather is likely to continue
well into next week with a series of disturbances likely to pass
near the northeastern US. The good news is that we aren`t expecting
any significant rainfall so flooding doesn`t look to be a concern
moving forward.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Through 18Z Tuesday...VFR conditions will prevail across all
terminals for the next several hours. As precipitation begins to
move into the region, ceilings will gradually lower and trend
towards MVFR between 00Z and 06Z Tuesday, especially across
northern terminals where more precipitation is expected. Within
some of the heavier rain showers, some MVFR visibilities may be
possible, with some thunder possible across northern New York.
Southerly winds between 6 to 12 knots will continue through the
forecast period, with gusts up to 20 knots possible this
afternoon and some LLWS possible at several terminals
overnight.

Outlook...

Tuesday Night: Mainly VFR, with local MVFR possible. Likely SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Wednesday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHRA.
Thursday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Thursday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Friday: VFR. Slight chance SHRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: Mainly MVFR, with areas VFR possible. Chance SHRA.

&&

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

&&

$$
SYNOPSIS...Kremer
NEAR TERM...Chai/Kremer
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...Kremer