508
FXUS61 KBTV 132349
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
749 PM EDT Wed May 13 2026
.WHAT HAS CHANGED...
As of 229 PM EDT Wednesday...
Forecast rainfall amounts continue to increase, mainly across the
eastern slopes of mountains and the spine of the Greens through
Thursday night. Totals from early this morning through Thursday
night range around 0.50-1.50 inches, with some localized around
2.00 inches. This will still be largely beneficial for the
region.
&&
.KEY MESSAGES...
As of 229 PM EDT Wednesday...
1. Wet weather continues for the second half of the week with
beneficial rains expected across the region.
2. Weather will be drying out into the weekend, allowing
temperatures to warm above seasonal normals.
3. Notable warm up for the beginning of next week.
&&
.DISCUSSION...
As of 229 PM EDT Wednesday...
KEY MESSAGE 1: Vertically stacked closed low pressure continues to
track across Lake Huron this afternoon. An associated warm frontal
boundary approaches northern New York and Vermont from the southwest
as well, producing a wave of rainfall that has spread across
northern New York and northern Vermont. Some drying within the warm
sector will take place this afternoon and evening, resulting in non-
zero instability values ahead of another boundary/trough axis
bringing more organized convective showers this evening and tonight.
High resolution models are projecting Surface CAPE values up to 300-
500 J/kg this afternoon in portions of northern New York, mainly
west of the Adirondacks, so a rumble of thunder is not out of the
question. The line of showers will move relatively slowly from west
to east across the forecast area tonight as winds decrease but
remain southerly, keeping temperatures above seasonal normals
overnight in the 40s and lower 50s. Additional rainfall amounts
tonight will be up to 0.45", highest amounts in the northern
Adirondacks. Where rain has fallen across northern New York, patchy
fog may develop as winds become lighter tonight.
Upper low pressure will track through New York and the mid-Atlantic
states on Thursday as its associated surface low pressure weakens.
It should eventually get absorbed into a strengthening surface low
pressure moving northeasterly out in the Atlantic Ocean late
Thursday. This will result in another round of rain with focus of
precipitation in the Adirondacks and eastward while the St. Lawrence
Valley misses out on much of the steadier rain (prob of precip 20-
60% in this area). Adirondacks and eastward, rain could be heavy at
times Thursday afternoon. A rumble of thunder is also not out of the
question in the afternoon, but overall instability looks minimal.
We`re expecting rain amounts of up to 0.75" over the course of the
day, highest amounts in the southern and central Greens, locally one
inch possible. Winds on Thursday should remain relatively light out
of the north for northern New York and the Champlain Valley, and out
of the east for the Greens and east of the Greens. Because of the
increased rain and clouds, high temps will remain below seasonal
normals in the mid 50s to lower 60s.
Thursday night, mid/upper low is expected to track into the Atlantic
Ocean east of New Jersey as the deep surface low in the ocean speeds
out to the Canadian maritimes. This will send more moisture through
the forecast area as well as light northerly to northeasterly
surface flow. Probability of precipitation is around 60-100%,
highest on eastern slopes of the mountains with easterly flow aloft.
Total rainfall amounts from early this morning through Thursday
night are expected to come to around 0.50-1.50 inches, with some
localized around 2.00 inches on the favored eastern slopes of
mountains as well as the spine of the Greens. With the more
northerly surface flow on Thursday night, we`ll see temperatures
near seasonal averages overnight with lows in the 40s. Where winds
are on the lighter side in the valleys of the Adirondacks and
eastern Vermont, we could see some patchy fog or mist develop as
well.
KEY MESSAGE 2: Friday will be a day of gradual drying as the upper low
finally shifts eastward, though showers may linger throughout the
day, mainly in higher terrain. The general drying trend will allow
temperatures to reach into the 60s for most areas, approaching
normal for this time of year. By Friday night, multi-layer ridging
will make for a drier night with lows again seasonable in the 40s.
Southwesterly flow will begin to increase late Friday night and
early Saturday morning, allowing temperatures to climb into the 70s
Saturday afternoon. Another trough and weak frontal boundary will
approach the region Saturday evening. There remains some uncertainty
on the timing and whether precipitation can develop, especially with
little in the way of forcing or instability beneath this ridge axis,
but a low end chance for some rain is possible in the late afternoon
and evening, mainly in the St. Lawrence Valley, Adirondacks, and
northern Vermont, up to 35% chance of measurable precip. After a
warm day, Saturday night should also be mild with lows in the upper
40s to mid 50s.
KEY MESSAGE 3: Ridging builds into the region from the southwest for
the beginning of next week, and surface high pressure becomes
centered near Bermuda. This will easily cause the warmest
temperatures of the year so far. By Tuesday, temperatures should be
in the 80s for most places, with a run at 90 possible for the
valleys. NBM probabilities range between 50-75 percent for the lower
Connecticut River Valley and between 25-50 percent for the Champlain
Valley away from the lake. Surface low pressure is expected to track
well to the northwest, so any wobbles in storm track should still
keep the region in the warm sector, though the exact extent of the
heat remains uncertain. A strong cold front will come through mid-
week with potential showers and thunderstorms.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...Showers and thunderstorms are edging into
St Lawrence County as of 23Z; it`s likely that -TSRA will impact
MSS 00-02Z with storms dissipating into showers afterwards while
they track eastward. The strongest convection is winding down
with loss of diurnal heating, so elevated instability will be
the only thing to sustain convection going forward. It seems
that a gap is forming in radar coverage and may largely miss SLK
through 06Z. Still rain chances will be increasing so light
rain/mist is possible through the nocturnal hours at all
terminals. Upper low is progged to stall over the region after
12Z with moisture conveyance off the Atlantic. Warm rain
processes will take over and allow CIGs to sag 06-12Z for most
terminals with IFR becoming increasingly likely. IFR could
become more intermittent 12-18Z, but continued rain and
upsloping is favored to win out with more widespread IFR
probable after 18Z. LLWS will be possible through 12Z mainly
from the Champlain Valley eastward as lljet tracks eastward.
Outlook...
Thursday Night: Mainly MVFR, with local IFR possible. Likely
SHRA, Patchy BR.
Friday: Mainly VFR, with areas MVFR possible. Slight chance SHRA.
Friday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Slight chance SHRA.
Sunday: VFR. Slight chance SHRA.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Storm
DISCUSSION...Storm/Myskowski
AVIATION...Boyd
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