000
FXUS61 KBTV 210237
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1037 PM EDT Wed Sep 20 2023

.SYNOPSIS...
High pressure is moving into the North Country, with several
days of pleasant weather expected. Cool nights and warm days
are expected, with seasonal fog in the river valleys likely the
next several days. A gradual warming trend is expected throughout
the rest of this week. A low pressure system will move up the
Atlantic coast, but some uncertainty remains on how far north
precipitation lifts into the region. At the very least, there
will be increasing cloud cover heading into Sunday and a halt to
the warming trend.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
1030 PM UPDATE...

Forecast remains very much on track so only made minor changes
to bring it up to date with current obs. Nighttime microphysics
satellite shows some patchy lower stratus development across
locations that have dipped below crossover temperatures.
However, webcams are now showing fog development yet so SLK,
which is currently at 41F, has a good chance of reaching the
forecast low of 32F. If it were to occur, this will be the
first 32 deg reading of the season for SLK. Looking at climate
history, the mean date for the first 32F or lower for SLK is
September 8. Existing Frost Advisories also remain in effect.


PREVIOUS DISCUSSION...

Surface high pressure building overhead will continue to be the
dominate weather feature over the next few days, bringing a
stretch of dry and pleasant weather. As skies clear towards the
overnight, good radiational cooling conditions are expected
across the region. Overnight low temperatures will fall into the
40s, with locations along Lake Champlain closer to 50. A Frost
Advisory is in effect for parts of northern New York as low
temperatures drop into the lower to mid 30s across portions of
the Adirondacks. Given the synoptic set up and the radiational
cooling tonight, fog development is expected across much of the
area, especially the favored river valleys.

Another beautiful late September day is in store for the region
tomorrow. Skies will be mostly clear with some fair weather
cumulus popping up, although skies might be a little hazy with
the HRRR showing some wildfire smoke aloft moving into the
Northeast. Temperatures tomorrow will be seasonable, although a
few degrees warming than today. Daytimes high will be in the
upper 60s, with the broader valleys reaching the low 70s.
Thursday night will be another great night for radiational
cooling and fog development, with overnight lows generally in
the 40s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 343 PM EDT Wednesday...The quiet stretch of weather continues
into Friday as surface ridge of high pressure gradually shifts east.
Our forecast area will remain on the western periphery of the
anticyclone, with a southeasterly onshore flow in place. High
temperatures on Friday will be in the low to mid 70s. Going into
Friday evening, will see high clouds begin to spread overhead
associated with a low pressure system to our south, with clouds
expected to thicken and lower through the night. Lows will be in
the 40s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 343 PM EDT Wednesday...The forecast trends more uncertain going
into the weekend with a coastal low pressure system advancing
northward up the East Coast. Models still don`t have a good handle
on what path the system will take after tracking over the Mid
Atlantic Coast, with potential interaction with northern stream
shortwave energy shunting the system south and east of our area
before being carried out to sea. This scenario would mean few
impacts to our area from the system outside of some increased cloud
cover and some rain for our southern counties. This scenario lines
up with the latest GFS/ECMWF deterministic forecasts, and is
supported amongst the ensemble guidance as well (GEFS and ECENS
showing only 20-30% chances of southern VT receiving over 0.1 inch
rain over the weekend, with even lower probabilities further north).
We are noting the NAM has a very different and much wetter forecast
for our area, but this is towards the end of the NAM forecast and we
are leaning away from this scenario at this time. Our current
forecast has most of our area dry through the weekend, except
southern Vermont, where we carry a 20-40 percent chance of showers
mainly Saturday night. However, this is subject to change as models
get a better handle on the forecast, so keep on top of latest
forecasts if you have plans this weekend.

The forecast for next week is looking very quiet as a surface ridge
sets up over Quebec. Have forecast temperatures near seasonable
norms for mid/late September and low chances of precipitation.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday... All terminals are currently VFR with mostly
clear skies and light winds. The VFR conditions will continue
through the overnight hours except where fog develops from strong
radiational cooling. Currently fog is expected to form at SLK, MPV
and EFK. There is high confidence of fog at SLK and MPV while there
is less confidence at EFK, but still enough to put fog in the TAF.
SLK could see fog around 04Z which is earlier than usual on
radiational cooling nights as the 00Z temperature is much closer to
its crossover temperature than normal at this point in the evening.
MPV and EFK will likely see fog after 06Z. The fog should lift
shortly after sunrise and all locations will improve to VFR through
the end of the TAF periods with mostly clear skies and light winds.

Outlook...

Thursday Night: VFR. Patchy BR.
Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Slight chance SHRA.
Sunday: Mainly VFR, with local MVFR possible. Slight chance SHRA.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.

&&

.EQUIPMENT...
The KCXX radar will be down for radome repairs, with a return to
service around September 21st.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...Frost Advisory from 2 AM to 8 AM EDT Thursday for NYZ029-030.

&&

$$
SYNOPSIS...Kremer
NEAR TERM...Chai/Kremer
SHORT TERM...Duell
LONG TERM...Duell
AVIATION...Myskowski
EQUIPMENT...WFO BTV