591
FXUS61 KBTV 121824
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
224 PM EDT Tue May 12 2026
.WHAT HAS CHANGED...
As of 222 PM EDT Tuesday...
No significant change have been made to the forecast.
&&
.KEY MESSAGES...
As of 222 PM EDT Tuesday...
1. Cool and dry conditions continue this evening into tonight
with increasing clouds and decreasing frost threats.
2. Conditions will trend wet by tomorrow morning with
widespread, beneficial rainfall tomorrow through Thursday.
3. Showers with embedded thunderstorms are possible Saturday
afternoon and evening, then temperatures warm above seasonal normals
for the first half of next week with additional shower chances to start
the work week.
&&
.DISCUSSION...
As of 222 PM EDT Tuesday...
KEY MESSAGE 1: Cool and dry conditions will continue into this evening
as high pressure quickly slides to the east. While temperatures will
lower once again tonight, increasing clouds from west to east
overnight, will limit the overall cooling that takes place. As such,
no frost headlines are expected tonight in the areas where the
growing season has started. However, there is still some potential
frost in the Northeast Kingdom where clouds may arrive slightly
later closer to tomorrow morning. Temperatures will still be chilly
with lows in the mid to upper 30s in Vermont to around 40 across the
St. Lawrence Valley.
KEY MESSAGE 2: There is little change in the overall synoptic pattern
for tomorrow into Thursday as an upper trough will close into an
upper low and slowly drift east. Model guidance has mostly settled
in on our next systems arrival just after sunrise across the St.
Lawrence Valley and reaching Vermont by the mid to late morning
hours. There has been a slight trend towards a slower slight more
west warm frontal lift however. The newest 12Z HRRR and NAM3K models
have trended towards a drier eastern edge to the the warm front
owing to a more west upper low centroid. HREF hourly rain rates also
denote this trend with lower rate values across Vermont.
Subsequently, strong diffluence aloft will also help shear the
frontal zone which may further reduce the rainfall that falls.
Regardless, there will be a period of light to perhaps some embedded
moderate rain tomorrow morning into early afternoon areawide. The
warm front lifts quickly north placing us into a messy warm sector
with plenty of cloud cover and moisture advection as the warm sector
becomes north to south oriented. Some clearing in the warm sector
may allow for some instability as CAMS denote 150-250 J/kg of SBCAPE
over northern New York embedded in a narrow strip of convection
tomorrow afternoon. A rumble of thunder cannot be ruled out, mainly
in St. Lawrence County and Franklin Counties of New York. Total
precipitation from the initial round of rain will be between a
quarter to around half an inch, with the higher amounts into the St.
Lawrence Valley.
The system then begins to lose steam as it becomes subsidence
dominated under closed off flow. The convective boundary Wednesday
night will stall somewhere near the Champlain Valley into Thursday
morning as flow aloft and moisture decreases. However, a baroclinic
zone will favor cyclogenesis off the New England coast allowing a
resurgence of a secondary low near Long Island in addition to yet
another low near the 40 N, 70 W benchmark. The benchmark low will
likely absorb the secondary low adding to the complexity of our
weather into Thursday. Moisture resurgence will be focused along the
washed out convective boundary around the Champlain Valley, of which
the exact position is still somewhat uncertain. Along this boundary,
however, an additional quarter to an inch from north to south is
expected. Rain will slowly pivot out of the region by Friday
morning. Total rainfall through Thursday night will range from half
an inch near the International Border to an inch to inch and a
quarter in southern Vermont and the Adirondacks. Locally in the
higher terrain, up to 1.50" is possible in southern Vermont and the
High Peaks of New York. Warm and more isolated to scattered
showers are expected Friday as the system exits, though not a
widespread rain by any means.
KEY MESSAGE 3: Friday night and Saturday morning will be a short-lived
drier period as multi-level ridging crests over the forecast area.
Surface high pressure will be displaced to the south, so it doesn`t
look like the most ideal radiational cooling night with lows near
typical mid-May values in the 40s. Then, another shortwave is expected
to move through northern New York and Vermont Saturday afternoon and
evening, bringing with it some warm air advection. The probability of
precipitation is around 25-45% during that period, highest along the
international border, closer to the parent low pressure in Canada.
Precipitation will likely be scattered showers with some embedded
thunderstorms possible during the peak of the warmth Saturday afternoon
as temperatures reach into the lower and mid 70s, several degrees above
seasonal normals. We should still be in the warm sector Saturday night
with lows in the mid 40s to lower 50s, then a weak frontal boundary
will clip the Northeast Kingdom on Sunday with PoPs 15-25% for the odd
shower. For the most part though, Sunday looks fairly dry. The frontal
boundary should keep highs Sunday from getting higher than the mid 60s
to mid 70s and keep lows seasonable in the 40s Sunday night. Upper
ridging and surface pressure stemming from Quebec will continue the
period of dry weather Sunday night before stronger warm air advection
kicks in ahead of our next storm system. Temperatures could soar into
the mid 70s to mid 80s the first two days of the work week while lows
sit in the upper 40s and 50s. Precipitation from this system is looking
most likely sometime Tuesday afternoon, but showers could begin as
early as Monday or Monday night.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Through 18Z Wednesday...VFR conditions are expected to prevail this
afternoon through around 12Z-16Z Wednesday with northwesterly winds
decreasing this evening, becoming light and variable or calm
overnight. Winds will then turn southeasterly early Wednesday
morning as clouds increase ahead of our next storm system.
Southeasterly flow will increase Wednesday as rain spreads across
the region. Timing of precipitation arrival is a little tricky with
a dry air mass in place ahead of the showers, resulting in a period
of virga before rain arrives in earnest. Rain showers should be
widespread and reaching the ground by around 12Z-16Z, bringing with
them ceilings around 1000-3000 feet above ground level that should
persist through 18Z Wednesday. Heavier showers could produce
visibilities 3-6 miles throughout Wednesday morning. Some guidance
suggests ceilings could reach IFR levels towards 18Z Wednesday, but
model consensus on this is poor, and the probability of IFR ceilings
is low over the next 24 hours. LLWS is anticipated at SLK and RUT
around 14Z-18Z Wednesday as a low level jet moves overhead,
spreading to the other sites after 18Z Wednesday.
Outlook...
Wednesday Night: Mainly VFR, with areas MVFR possible. Definite
SHRA.
Thursday: MVFR. Definite SHRA.
Thursday Night: Mainly MVFR, with local IFR possible. Likely
SHRA.
Friday: Mainly VFR, with local IFR possible. Chance SHRA.
Friday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Saturday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Saturday Night: VFR. Slight chance SHRA.
Sunday: Mainly VFR, with local MVFR possible. Slight chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Storm
AVIATION...Storm
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