000
FXUS61 KBTV 112353
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
753 PM EDT Thu Apr 11 2024

.SYNOPSIS...
Expect mild and rainy conditions through Friday afternoon with
widespread 0.5 to 1 inch, locally up to 1.5 inches of rain. The
rain combined with snowmelt runoff will lead to rivers rising to
bankfull and localized ponding of low-lying areas. Southeast
winds increase tonight, gusting 40 to 50 mph, locally 55 mph
overnight tonight into Friday morning. Saturday will be
unseasonably cool, with mixed rain and snow showers and minor
accumulations possible above 1500 ft elevation. Drier and
pleasant weather returns on Sunday into early next week before
the weather turns unsettled middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
As of 524 PM EDT Thursday...Have examined the new 18z data and
have concerns for localized gusty south/southeast winds
associated with deepening sub 980mb low pres lifting acrs the
central Great Lakes tonight into Friday. I have updated to
issue wind advisory for western slopes and northern dacks from
2Z this evening to 18z Friday. Thinking localized gusts 45 to
55 mph are possible within the advisory area from late this
evening through early Friday aftn. Several periods of gusty
winds are possible, first is late this evening over northern NY
associated with 925mb jet of 50 knots, second is on Friday
morning as initial batch of precip lifts north of cwa and well
defined dry slot moves into our cwa, promoting better/deeper
mixing profiles. This dry slot is colocated with exiting 850mb
jet of 55 to 75 knots, while 925mb winds are 50 to 60 knots,
especially northern NY into northern VT, including most of
Franklin County. For these reasons, thinking localized gusts 45
to 55 mph are possible, along with isolated power outages
possible. Rest of fcst in good shape and no update needed.

Previous discussion below:
A warm front is shifting north of the area now. A small window
for drying conditions is expected with sharp falls in relative
humidity expected in the 700-500hPa layer. As that moves across,
flow begins to accelerate. 925hPa winds will increase to 40 to
50 knots, and up at 850hPa increase towards 65 knots. South-
southeast flow suggests the most favorable potential for gusty
winds along the northern slopes of the Adirondacks, but strong
gusts could also occur from channeled flow within the Champlain
Valley. A localized gust to 50 mph is possible in and around
Malone, New York. Generally 35 to 45 mph is expected in the
Champlain Valley and 30 to 40 mph across eastern Vermont and the
St. Lawrence Valley between about 9 PM tonight through 9 AM
tomorrow morning. The period of uncertainty for wins will be
after midnight or so, when increasing moisture could stabilize
conditions near the surface. There appear to be a couple rounds
of fast moving precipitation overnight. By Friday morning, these
batches of rain will be exiting the region, and winds should be
starting to abate, but remain breezy. Warm weather with mid 40s
to mid 50s is expected, but a few locations within the
Champlain Valley and St. Lawrence Valley my just sit below 60.
Combined with rain and snowmelt, we should begin to see more
appreciable river rises. For details, please see the hydro
discussion at the end.

Friday afternoon, the occluded boundary will shift through. Within
the dry slot, modest surface destabilization will occur while
temperatures climb into the 60s. With surface dewpoints still in the
mid 50s, we should be able to achieve 200-500 J/kg of CAPE.
Convective enhancement with convergence along the boundary and good
jet dynamics should produce efficient rainfall processes given our 1-
1.25" PWATs. But we aren`t done yet. The upper low will track
overhead, with an embedded shortwave digging on the western
hemisphere of the upper low. With abundant low-level moisture, we
will see chances of showers continue into Saturday. However, the
snowmelt component should come to an end. Friday night, snow levels
will fall towards 1200-1500 ft elevation as cold advection takes
place. Friday night temperatures will sink sink into the lower 30s
to about 40 over New York, and generally remain in the 40s over
Vermont.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
As of 253 PM EDT Thursday...Sub-freezing 925mb air mass will be
advecting into northern NY early Saturday morning, so temperatures
on Saturday will not climb all that much. Surface low pressure
tracks from eastern MA into southern Maine, which would a favorable
track for accumulating snow in our region a few weeks earlier but
given it is mid April, it looks to be a cold rain for most. That
said, model guidance suggests that there could be some minor snow
accumulation down to 1000 ft elevation. Upslope snow showers could
bring 1 to 3 inches of accumulation above 1500 ft. No road impacts
are expected, although it will be a rather raw day by mid April
standards. Highs only top out in the mid to upper 40s for many
valley locations, which is about 5 to 10 degrees below
climatological normal. Higher elevation locations would struggle to
make it out of the 30s on Saturday. Westerly winds gusting 25 to 30
mph would make it even colder, with wind chills in the 20s and 30s
during the daytime.

Upper ridging starts to build in from the west overnight Saturday.
Plenty of cloud cover and boundary layer not decoupling should limit
radiational cooling should help keep overnight lows in the mid 30s
to low 40s in the valleys, with sub-freezing temperatures for the
colder hollows. This should set the stage for a rather pleasant
Sunday and second half of the weekend, with sunshine and 50s
returning across much of the CWA. Winds shift to the southwest, and
while it will be breezy, it would not be quite as blustery as on
Saturday. So get outside and enjoy the nice spring day.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 253 PM EDT Thursday...Upper ridging builds in early next week
so pleasant weather will prevail on Monday into Tuesday. Then the
pattern becomes more unsettled towards mid week as we watch a upper
level disturbance emerge out of the Four Corners region and track
towards the Great Lakes. The impacts from this feature will depend
on how far west the low pressure tracks with respect to our region.
For now, have largely stuck to blended guidance. After the system
exits, spring fever looks to step up a gear as the CPC 6-10 day
outlook shows 70 to 80 percent probability of above normal
temperatures for our region. With average highs in the 50s for this
time of the year, highs in the 60s look to be a good bet as we
finish the work week.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Through 00Z Saturday...Terminals in the region have a mix of flight
categories and relatively persistent conditions will prevail
throughout the TAF period until ceilings begin to fall later in the
day tomorrow. Ceilings at MPV should rise to MVFR later in the night
but there is high uncertainty at the precise time. Ceilings at EFK
could drop to IFR conditions tonight for a period of time if rain
showers provide enough low level moisture to lower the ceilings.
There will be some on and off showers throughout the TAF period and
the heaviest ones could briefly lower visibilities to MVFR but
these should be widely scattered. LLWS will persist tonight and
into the day Friday before going away when the low-level jet moves
out. Winds will stay strong throughout the TAF period but they will
trend more westerly as the day on Friday progresses.

Outlook...

Friday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Saturday: Mainly MVFR, with local IFR possible. Definite SHRA.
Saturday Night: Mainly MVFR, with areas VFR possible. Chance
SHRA, Chance SHSN.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA.
Sunday Night: Mainly MVFR, with areas VFR possible. Chance SHRA.
Monday: Mainly VFR, with areas MVFR possible. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.

&&

.HYDROLOGY...
Well above normal conditions tonight into tomorrow in combination
with several rounds of rain will result in river rises through
Friday. Rainfall amounts will favor southern portions of the
Adirondacks and south-central Vermont, where storm total liquid will
be between about 0.50-1.25" The remaining snow pack is mainly above
2000 foot elevation. There`s not much left to melt, but the higher
summits still have plenty of snow, and we lost about 0.50-1.00" of
snow water equivalent in the existing pack last night. River rises
have so far been somewhat below forecast river levels. However,
greater warmth tonight and primed soils will likely result in more
run-off into rivers. Otter Creek at Center Rutland (CENV1) and the
East Branch of the Ausable at Ausable Forks (ASFN6) are currently
forecast to remain in their banks. Any additional snowmelt or
rainfall beyond present forecast expectations could send these
rivers into minor flooding and other main stem rivers towards
bankfull. Beyond river flooding, several rounds of rain and snowmelt
could result in ponding and localized flooding along low-lying farm
fields.

&&

.EQUIPMENT...
KSLK and KPBG are experiencing comms issues. Dataflow may be
sporadic.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Wind Advisory until 2 PM EDT Friday for VTZ002-016>019.
NY...Wind Advisory until 2 PM EDT Friday for NYZ028>031.

&&

$$
SYNOPSIS...Haynes
NEAR TERM...Haynes/Taber
SHORT TERM...Chai
LONG TERM...Chai
AVIATION...Myskowski
HYDROLOGY...Haynes
EQUIPMENT...NWS BTV