FXUS61 KBTV 210537
Area Forecast Discussion
National Weather Service Burlington VT
137 AM EDT Thu Sep 21 2023
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 FRIDAY/...
As of 122 AM EDT Thursday...Minimal tweaks to the forecast as
weather remains quiet, just some minor adjustments made to
temperatures around Lake Champlain since the area is remaining
mild. Also increased winds on the lake as well as the summits to
better match observations. Still expecting lows to reach the
mid-30s to upper 40s tonight when all is said and done. Fog is
beginning to really blossom across the river valleys as
anticipated, and the Frost Advisories remain in effect for
southern Franklin NY and southeastern St. Lawrence NY. Previous
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
.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 /06Z 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.