631
FXUS61 KBTV 020240
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1040 PM EDT Thu May 1 2025

.SYNOPSIS...
Widespread showers and potential for a rumble of thunder are
expected overnight as a front moves through the region. A
fairly unsettled pattern ensues for the end of the work week and
into the weekend with multiple rounds of showers expected.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 1035 PM EDT Thursday...Increased precipitation chances and
with widespread showers evident from the Champlain Valley
westward. Also, slight chances of thunderstorms were introduced
overnight after midnight through around daybreak as a trough
moves through. Lightning is evident southwest of the Adirondacks
over portions of central New York and latest guidance from CAMS
are more supportive of some elevated instability tracking across
the North Country after midnight. As such, it warrants adding
some slight chances of thunderstorms prior to daybreak with the
trough moving into New Hampshire shortly after sunrise.

Previous Discussion...Surface high pressure surrounds the
forecast area this afternoon with a primary anticyclone just off
the coast of Cape Cod and a secondary one overhead. Aloft,
upper- to mid-level ridging has crested over the Northeast,
making for a lovely Spring day with temperatures widely in the
60s and skies mostly clear.

Unfortunately, the hours of these favored conditions are
numbered. Latest visible satellite images indicate high-level
clouds approaching the forecast area well ahead of a surface low
tracking north and east into the Great Lakes region from the
Midwest. Aloft, a weak shortwave disturbance attends the track
of this cyclone, providing mid- to upper-level support for
ascent to that in the low levels supplied by warm air advection
ahead of the southeast-extending, low-level warm front. As the
surface cyclone and associated shortwave continue to track north
and east towards the northeast Great Lakes tonight, light showers
will spread into northern New York and northern Vermont with
southerly flow promoting orographic enhancement and subsequent
embedded heavier showers at higher elevations. By tomorrow
morning, accumulated precipitation looks to reach values of
about 0.10" to 0.25" with locally higher amounts up to 0.35". Low
temperatures tonight will fall to the mid/upper 40s to low 50s.

The aforementioned low and its attendant warm front will slowly
track north and east tomorrow with additional rounds of light
showers expected throughout the morning. As the low begins to
move overhead tomorrow afternoon, the warm front will make its
passage through the region, placing us in the warm sector ahead
of the progression of the system`s trailing cold front. With dry
air entraining into the southern periphery of the low, a brief
break in showers and some breaks of sun will lead to a
regionwide increase in instability tomorrow afternoon into early
tomorrow evening. Highest SBCAPE values range from around
300-800 J/kg with low-level lapse rates on the order of 7.5-8
C/km. This is especially true within northern Vermont, where
some scattered thunderstorms will be possible late tomorrow
afternoon into tomorrow evening. At this time, severe
thunderstorms are not expected, though gusty to strong winds
could occur as a result of any thunderstorms that develop,
especially those with embedded heavier downpours. High
temperatures tomorrow will rise into the low 60s to low/mid 70s.
And, as daytime heating is lost, the chance for thunder will
diminish and a brief return to mainly dry conditions returns
after 2 AM.

&&

.SHORT TERM /SATURDAY NIGHT/...
Showers once again increase across the region Saturday as the
cold front slowly tracks south and east. These showers may
become a bit more scattered in nature as a weak surface high
slides eastward from the Upper-Midwest and provides
counteracting subsidence to lingering ascent within cyclonic
flow. Highs Saturday will be a bit cooler than Friday with
values in the 50s and 60s. Upon the passage of the cold front
Saturday night, low temperatures will fall primarily to the
upper 30s to upper 40s with shower coverage gradually dwindling
to the south and east.

Sunday`s forecast is almost a rinse and repeat of Saturday with
a brief break in precipitation throughout the morning and a
gradual spread of additional showers in the afternoon. This
time, showers look to spread northward as the aforementioned
cold front stalls to our south and a cutoff low develops in the
Ohio and Tennessee Valleys. A southerly moisture fetch off the
Southeast Coast will reinforce moisture across the region with a
surface wave providing enhanced convergence and subsequent
ascent to generate and sustain additional showers. However, the
spatial extent of rain is uncertain on Sunday given the
uncertainty in the position and prorogation of the cutoff low
to out south and west. So for now, maintained slight chance to
chance Pops across much of the region. With little in the way of
instability, however, thunderstorms should be mitigated Sunday.
Highs will be in the mid/upper 40s across higher terrain to low
60s in valley areas.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Unsettled conditions persist through the long term forecast
period due to the stationary, vertically stacking cutoff low in
the Ohio and Tennessee Valleys. Additional rounds of showers are
therefore expected across the forecast area through at least
Wednesday night as the low slowly makes progress north and east.
However, much like in the short term, there is still uncertainty
in the track and evolution of this system, so there are
differences in the run to run guidance pertaining to when we can
expect a return to dry conditions. Therefore, for much of the
long term period, slight chance to chance PoPs were maintained
with the greatest confidence in more widespread showers Tuesday
into Tuesday night. Here, likely PoPs were included to convey
this confidence. High temperatures throughout the extended
period will primarily be in the 50s and 60s with 40s at higher
elevations, but Wednesday will be the warmest of the period with
50s to low 70s. Low temperatures will be in the 40s and 50s.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Main aviation concern
will be LLWS ahead of a frontal system associated with a
moderately strong southerly low level jet. SFC winds will be
generally less than 10kts overnight as a 55kt low level jet
moves across the region. These conditions will persist mainly
from the 03-18Z time frame. After 10Z, SFC winds begin
increasing as faster winds begin to mix to the surface. Gusts
20-30kts are expected in the 14-18Z range with gusts to around
30kts continuing at MSS through the end of the period as winds
become southwesterly and channel down the St Lawrence Valley.
Rain is moving in from west- southwest to east northeast as a
frontal system moves into the region. Otherwise, VFR conditions
will largely prevail, except 08-16Z where CIGS for some
terminals lower mainly to MVFR. SLK/MPV could see a period of
IFR CIGs. CIGs begin to raise 16-00Z heading back towards VFR
for most terminals.

Outlook...

Friday: Mainly VFR, with local MVFR possible. Windy with gusts to
30 kt. Chance SHRA.
Friday Night: VFR. Chance SHRA.
Saturday: Mainly VFR, with areas MVFR possible. Likely SHRA.
Saturday Night: Mainly MVFR, with areas VFR possible. Chance
SHRA.
Sunday: Mainly VFR, with areas MVFR possible. Slight chance SHRA.
Sunday Night: Mainly VFR, with local IFR possible. Slight chance
SHRA.
Monday: Mainly MVFR, with areas VFR possible. Slight chance SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...NWS ALY
NEAR TERM...Boyd/NWS ALY
SHORT TERM...NWS ALY
LONG TERM...NWS ALY
AVIATION...Boyd/NWS ALY