FXUS61 KBTV 210759
Area Forecast Discussion
National Weather Service Burlington VT
359 AM EDT Thu Sep 21 2023
High pressure will continue to build across the forecast area
through the end of the week, resulting in warm, sunny days and
clear, chilly nights featuring fog in river valleys and potentially
even some isolated frost in the Adirondacks. A low pressure system
will likely approach the area during the weekend, increasing cloud
cover, but uncertainty remains on whether we`ll receive any rain
showers from this system.
.NEAR TERM /THROUGH FRIDAY/...
As of 359 AM EDT Thursday...High pressure keeps the region fairly
quiet weather-wise through Friday. Today will feature seasonable
highs in the mid-60s in the Adirondacks and Northeast Kingdom and
lower 70s for the wider valleys with a slight warming trend tomorrow
- highs instead in the upper 60s to lower 70s, warmest in the wider
valleys. Otherwise sunshine will be abundant both days and winds
will be light. Tonight will be chilly with the lack of insulating
clouds and lows should drop into the lower/mid-30s in the cold spots
of the Adirondacks to mid-40s close to the mild waters of Lake
Champlain. It won`t be as chilly as last night, but there could
still be some isolated frost or freezing fog developing in the
Saranac Lake area of Franklin County, NY. Elsewhere, regular fog
will likely be plentiful once more under such clear skies and high
pressure, especially in river valleys.
.SHORT TERM /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
.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 /08Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Fog is beginning to blossom across the
river valleys of our forecast area tonight, dropping several
sites to IFR. Sites most likely to retain the IFR conditions
through around 12-14Z Thursday are KMPV and KSLK, as is typical
for them. KRUT was a little more unexpected, and it has since
gone back to VFR, but the return of IFR cigs can`t be ruled out
there and we have gone with a tempo for a few hours to
communicate the variability in category expected tonight. Two
other sites that could dip into IFR category are KEFK and KMSS,
though there is slightly less confidence with these. Guidance is
not in strong agreement about KEFK, and this site is known for
bouncing up and down through categories, so thought the tempo
group would best suit what we anticipate tonight. KMSS is also
not a slam dunk with guidance disagreeing, and there could be a
light wind there overnight due to valley channeling, but overall
the thick surface moisture forecast there should be enough to
bring it down to IFR periodically under such clear skies.
Lastly, KPBG and KBTV should be spared MVFR or IFR conditions
tonight, but if fog travels up the Winooski River Valley towards
the airport and we take on some light easterly winds again, it
could be vicinity fog or even high MVFR at KBTV. We are another
day removed from rain, but the pattern with high pressure makes
tonight ripe for fog and therefore lowered vis threatening IFR
conditions. By around 14Z Thursday, fog should be over and we`ll
have VFR conditions through the rest of the day.
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: Mainly VFR, with areas MVFR possible. NO SIG WX.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.
The KCXX radar will be down for radome repairs, with a return to
service around September 21st.
NY...Frost Advisory until 8 AM EDT this morning for NYZ029-030.