257
FXUS61 KBTV 041926
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
326 PM EDT Sun May 4 2025
.SYNOPSIS...
Cool and unsettled weather continues through early this upcoming
week across the North Country, with additional showers likely and
temperatures slightly below normal. The highest probability of
precipitation and heaviest rainfall amounts tonight into Monday will
be across Rutland and Windsor counties, localized amounts greater
than 1 inch are possible. Very little rainfall is expected near the
International Border. Temperatures only cool into the mid 40s to mid
50s tonight and highs in the mid 50s to mid 60s on Monday.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
As of 326 PM EDT Sunday...Fcst challenge is pops and amount of qpf
over the next 12 to 24 hours as a closed cyclonic circulation
remains parked over the Ohio Valley. These deep closed 7h/5h
circulations always present challenges with regards to pop timing
and precip amounts and the potential for flooding needs to be
monitored closely over the next couple of days.
RAP UA and GOES-19 water vapor shows a closed and vertically stacked
system over the Ohio Valley with deep rich moist conveyor belt acrs
the eastern seaboard into central PA. The combination of strong ulvl
divergence in the hght fields and rrq of 250mb jet is helping with
deep synoptic scale ascent and associated cooling cloud tops over
central/eastern PA/NJ attm. Meanwhile, strong high pres and
associated deep dry layer with pw values <0.30" is trying to push
south toward our northern cwa. Guidance consensus supports mean 850
to 500mb RH proggs <30% near the International Border by 00z this
evening, while pw values are surging northward over southern VT with
a sharpening moisture gradient. In addition, to deep layer moisture
advection, areas of enhanced mid lvl frontogenesis and mid lvl
deformation is lingering acrs Rutland/Windsor counties tonight. This
synoptic scale ascent wl interact with a lingering stationary
boundary over southern New England to produce periods of rain
overnight into Monday. Rainfall amounts will be between 0.50 and
1.0" with localized higher amounts possible on the favorable
southeast upslope areas of eastern Rutland/western Windsor counties.
HREF prob of qpf >1.0" is near 100% along and south of Route 4,
while prob of 2.0" or greater is south of our cwa. A strong/tight
north to south qpf/pop gradient is anticipated with very little near
the Border. I have pops near 100% south and <10% north tonight into
Monday.
By midday Monday deeper moisture is lifting back northward acrs our
central cwa, along with another axis of favorable 700mb
frontogenesis. Expecting rain shower activity to expand northward
midday Monday, especially as 925mb to 850mb southeast jet of 35 to
45 knot strengthens and helps to enhance better llvl moisture
convergence. Some downslope shadowing is likely along the western
slopes, along with localized gusts 20 to 30 knots, especially toward
00z Tues. Given the lack of instability tonight and Monday, feel
rainfall rates should limit any potential flooding, but we always
have to watch these deep and slow moving closed systems. Highs on
Monday wl once again be influenced by clouds with warmest values
north and coolest south, where clouds/precip are the most likely.
Generally highs in the mid 50s to mid/upper 60s acrs our fa.
Additional moisture and lift rotate from south to north acrs our cwa
on Monday night with more showers likely. Greatest concentration and
highest pops wl be in favorable southeast upslope areas, as 925mb
southeast jet strengthens to 40 to 45 knots overnight. Lows very
similar to previous couple of nights, mainly 50s.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
As of 326 PM EDT Sunday...Our friend the upper-level low will finally
begin to move to the northeast as blocking in the Atlantic breaks
down Tuesday. The low- level jet will continue Tuesday morning across
the mountain peaks, with gusts nearing 45 knots. Due to the
inversion, mixing towards the valleys should be limited, but
locations immediately west of the Greens and Adirondacks above 2000
ft could see continued gusty winds Tuesday morning, before calming
into Tuesday afternoon. The axis of moisture along the warm conveyor
belt will begin to surge northward with more widespread
precipitation likely across south-central Vermont during the day
Tuesday. In the areas under the moisture axis, QPF amounts between a
quarter to half an inch of rain is possible between Tuesday and
Wednesday. NBM 24-hr probabilities of 0.5 inches in southern Vermont
Tuesday into Wednesday are between 30- 50%, with higher amounts in
southern/eastern New England. Depending on the exact track of the
low, higher precipitation could slide north/west into our region, as
CAMs are suggesting. We will continue to monitor trends as the
system draws closer. As the center of the low tracks into the St.
Lawrence Valley by Tuesday afternoon, underneath the low,
instability will increase with SBCAPE mean values between 200-400
J/kg. Some scattered convection is possible Tuesday afternoon in
portions of St. Lawrence County, but should quickly dissipate
overnight Tuesday as clouds and mid-level warming increase,
decreasing the instability.
By Wednesday, light shower activity continues under south-
southeasterly flow. Like Tuesday afternoon, underneath the low,
marginal instability could build by the afternoon, with widespread
slight chances for thunderstorms. Temperatures will be heavily
dependent on any cloud cover that develops with any showers. With
any breaks and sunshine, 925hPa temperatures are around 10-12 C,
meaning 60s to 70s for highs both days are expected. Tuesdays low
will be relatively mild with values in the 50s across the valleys
and upper 40s for the higher terrain.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 326 PM EDT Sunday...The main upper low finally begins to move
out of the region Wednesday night as the overarching trough swings
to the east. However, as the low exits, a surface cold front will
push into the area with lingering rain chances again. Temperatures
Wednesday night will be seasonably chilly in the 40s. Following the
front, temperatures quickly rebound back into the upper 60s for the
weekend with lows in the 40s. New guidance suggests a lower chance
of any frost/freeze potential Friday and Saturday morning from
previous guidance. Just as we think the precipitation might finally
be clear, another upper low looks poised to develop Thursday into
Friday across the Mid-Atlantic. Models are in disagreement on the
track and timing of this system. One solution shows a more
progressive low moving into the Gulf of Maine by Saturday with
little precipitation chances for the weekend, outside of portions of
the Northeast Kingdom. Another solution indicates a slower moving
system that retrogrades back into our region Saturday into Sunday,
making for yet another wet weekend. NBM probabilities of
precipitation still show near 20% overall, however, the trend has
been towards increased chances of rain for sun lovers. If you were
hoping for a completely dry weekend, it still is in play, but
chances are quickly diminishing.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...Blocked flow continues in the CPV this
aftn, but drier surface dewpoints and a wind shift to the
east/northeast by this evening should help to improve any
lingering IFR cigs to a mix of MVFR/VFR. Crntly northerly TAF
sites (PBG/MSS/SLK/EFK/BTV) have VFR conditions, while RUT/MPV
have IFR cigs. Based on webcams and sounding data feel IFR at
MPV should become MVFR CIGS in the next 1 to 2 hours. Meanwhile,
northerly blocked flow will continue to produce IFR cigs thru
21z, before winds slowly shift to the east/northeast by sunset
and MVFR cigs develop. In addition, after 03z low level
easterly winds near ridgetop increase at 35 to 40 knots, which
will increase turbulence and shear near RUT overnight into
Monday. Otherwise, northern taf sites should stay VFR thru the
next 12 to 18 hours.
Outlook...
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Tuesday: MVFR/IFR conditions possible. Chance SHRA.
Tuesday Night: Mainly MVFR, with areas IFR possible. Chance SHRA.
Wednesday: Mainly MVFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.
Wednesday Night: Mainly IFR, with areas MVFR possible. Slight
chance SHRA.
Thursday: Mainly MVFR, with local VFR possible. Slight chance
SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Danzig
LONG TERM...Danzig
AVIATION...Taber
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