918
FXUS61 KBTV 042319
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
719 PM EDT Sat Oct 4 2025
.SYNOPSIS...
High pressure will remain the dominant weather feature through
this weekend with temperatures climbing well above normal, with
some daily record high temperatures in jeopardy tomorrow and
Monday. Low relative humidity values and breezy to gusty winds
are possible Monday ahead of our next cold front on Tuesday.
Precipitation chances associated with the cold front look to
increase Tuesday into Wednesday, with cool and dry conditions
returning for the later half of the week.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 200 PM EDT Saturday...Dry and increasingly warmer air will
continue to filter into the area as high pressure crests today
overhead, and begins to shift east by tomorrow. Southerly flow will
allow decent waa with 925mb temperatures today and tomorrow surging
to 20-21C, leading to near record warmth for this time of year,
nearly 10-15 degrees above normal at the surface. Highs today could
reach near 80 across Vermont, and by tomorrow into the low to mid
80s everywhere outside of the higher terrain. Daily high records for
tomorrow will likely be in jeopardy under this pattern, with the
best chance to break daily high records tomorrow over the next 3
days. Southerly flow will keep temperatures mild tonight in the 50s
which will be near record high lows for a few climate sites.
Dewpoints will be slightly higher than yesterday with southerly
flow, however, with temperatures also higher, relative humidity
values will still be in the 30-40% this afternoon and tomorrow
afternoon. The lowest minimum RH today will be across southern
Vermont in the Connecticut River Valley, and tomorrow across the St.
Lawrence Valley. Increasing temperatures and continued low RH values
will continue to exacerbate the ongoing drought.
As the ridge peaks today and begins to shift east tomorrow, there
will still be some gradient flow, with winds generally southwesterly
and on the breezy side near 10 mph. Channeled flow in the Champlain
Valley will relax this afternoon for more calm winds tonight.
Channeled flow will return tomorrow morning as it did today in
the Champlain Valley with winds around the lake 10 to 15 mph.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 200 PM EDT Saturday...Monday will continue the warming trend
from this weekend with 925mb temperatures still in the 20-21C range.
Highs will be in the low to mid 80s outside of the higher terrain
and upper 70s in the Adirondacks. It will be warm, though not as
warm as Sunday. The ridge will shift eastward allowing increased
south/southwesterly flow. Efficient vertical mixing Monday afternoon
should help to dramatically dry out the vertical column of the
atmosphere leading to a good dewpoint bomb scenario. Relative
humidity values Monday will drop to near 30% areawide with some
25-30% not out of the question under potential dewpoint bombs. The
best dewpoint bomb conditions will be across Vermont east of the
Greens as downsloping off the Greens will aid mixing in addition to
less cloud cover expected than over northern New York. Mixing Monday
will also lead to gusty conditions. By Monday afternoon, a cold
front will begin to approach the area with a low-level jet
developing over the region. Gusts 20-25 mph are possible in the St.
Lawrence Valley, with similar gusts possible in Vermont,
particularly in areas that see efficient mixing and lower RH values.
NBM guidance does not appear to handle this mixing nor winds ahead
of the front well, thus some winds may be increased across the St.
Lawrence in future forecast updates. These low, near-critical RH
values, and increasing confidence in gusty winds, could lead to fire
weather concerns Monday afternoon should these trends continue. The
cold front begins to enter the area with increasing precipitation
chances (20-30%) by late Monday night towards Tuesday morning.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 216 PM EDT Saturday...Focus of this period is on welcome
rainfall Tuesday through Wednesday morning. Thereafter, dry and
much cooler weather will return as another large area of
Canadian high pressure will settle into the region. A mostly dry
cold front may also bring a brief period of showers in the late
Friday/Saturday timeframe, but predictability of this feature
is low.
High probabilities (close to 100%) of rain continue for midweek with
a strongly forced area of rain along and just behind a well-defined
cold front. Forecast soundings are consistent with a slight chance
of thunder in any convective elements. Warm, moist low level air,
especially around the 850 millibar level, will support at least
elevated instability and rumbles of thunder. GEFS Machine Learning
24-hour thunder probabilities in the 10-20% range seems reasonable
on Tuesday. Given height falls coincident with the surface front and
30 to 40 knots of deep layer shear, if we had more heat and humidity
to boost instability there may have been some severe weather
potential. However, even 90th percentile surface based CAPE (a
reasonable high end value) is in the 300 to 500 J/kg range. Instead,
a good soaking rain remains the main impact of this event, with
localized ponding of water in poor drainage areas. Through Tuesday
evening, most of the rain will likely be over far northern Vermont
and much of northern New York; thereafter, rain will shift south and
east with several hours of rain leading to amounts averaging 0.5" to
0.75". The model spread suggests realistic low amounts in the 0.25"
to 0.5" will probably occur, along with winners receiving near or
even a bit more than an inch of rain in localized areas.
Cessation of rain Wednesday morning, and those higher end amounts,
remain a point of contention related to two camps of model guidance.
Either rain will be exiting the region, or another wave of soaking
rain could move across most or all of the Adirondacks and much of
Vermont before ending Wednesday afternoon. The GFS continues to
depict a lagging trough and shortwave emerging from the central US
to force widespread rain mainly in our southern areas. And yet,
probability of measurable rain after 8 AM is only as high as 30%, so
most guidance at this time suggests this outcome is unlikely. What
is likely is much cooler conditions will settle into northern New
York and Vermont during the day. A brief period of gusty north winds
will be possible, especially on Lake Champlain which would produce
rough seas. Temperatures could be about 20 degrees lower during the
afternoon than 24 hours prior.
Another round of frost and freeze headlines then will be needed
Wednesday night, and possibly Thursday night, as dry and seasonably
chilly air will be present. Ensemble mean 925 millibar winds
Wednesday night show flow will be diminishing aloft in northern New
York, but relatively strong farther east as the high pressure area
approaches and then crests over the area during the day Thursday.
Then in contrast, as the high moves to the east, low level winds
Thursday night will pick up in northern New York and be lightest in
the Upper Valley in Vermont, suggesting a chillier night in eastern
Vermont than Wednesday night when a freeze is more likely.
Due to the expected light winds through this period and recent rain,
fire weather concerns will temporarily be low. Thereafter, Friday
looks like a potentially breezy day ahead of another cold front.
Would expect good channeling and we`ll possibly see lake wind
advisory conditions for Lake Champlain. With southerly flow, maximum
wind gusts above 25 MPH are favored in the northern Adirondacks,
northern Champlain Valley, and St. Lawrence Valley where current
probabilities are 30-60%. Early indicators for minimum relative
humidity are for values to drop into the 35-45% range, with a
pattern broadly similar to what we will see on Monday but with a
much cooler air mass.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
Through 00Z Monday...VFR conditions will persist through the
evening. Patchy fog will develop later in the night and confidence
has increased a little in it having wider coverage. It is possible
at MPV and SLK, with maybe a 70 percent chance for it forming at MPV
and maybe a 40 percent chance of it forming at SLK. The fog lifts
quickly after sunrise and VFR conditions will persist for the rest
of the day. Winds will be light and terrain driven this evening,
before becoming southerly to southwesterly during the day tomorrow.
Speeds up to 10 KTs are expected, except at BTV and PBG where gusts
up to 15 KTs are possible.
Outlook...
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: Mainly VFR, with local MVFR possible. Definite SHRA,
Slight chance TSRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Definite
SHRA.
Wednesday: Mainly VFR, with local IFR possible. Slight chance
SHRA.
Wednesday Night: VFR. Patchy frost.
Thursday: VFR. NO SIG WX.
&&
.CLIMATE...
Incoming heat this weekend is presently forecast to approach daily
record values. The most likely dates for records will be Sunday
October 5th and Monday October 6th. Below are some of the daily
records in jeopardy of being broken (current forecast at or within 3
degrees of the record).
Record High Temperatures:
October 5:
KBTV: 83/2023
KMPV: 82/1951
KPBG: 80/2005
KMSS: 85/1991
KSLK: 83/2023
October 6:
KBTV: 82/1990
KMPV: 79/1990
KMSS: 81/2005
KSLK: 80/1946
Record High Minimum Temperatures:
October 5:
KPBG: 56/1973
October 6:
KBTV: 64/1937
October 7:
KBTV: 62/1947
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Danzig
NEAR TERM...Danzig
SHORT TERM...Danzig
LONG TERM...Kutikoff
AVIATION...Myskowski
CLIMATE...BTV
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