National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 261115
AFDBTV

AREA FORECAST DISCUSSION
National Weather Service Burlington VT
715 AM EDT Fri Apr 26 2019

.SYNOPSIS...
A warm front associated with a developing storm system over the
Ohio Valley will produce occasional showers today. As surface
low pressure deepens, gusty southeast winds will develop along
the Western Slopes this afternoon with the threat for scattered
showers. Additional showers will develop along a cold front
this evening with cool and unsettled weather anticipated for
Saturday. Highs will range from the mid 40s eastern Vermont to
upper 50s parts of the Champlain and Saint Lawrence Valleys, but
cool back into the 30s and 40s on Saturday with some snow
showers possible in the mountains.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 709 AM EDT Friday...Updated to expand 100% further north
based on radar and observations. Also, cut temps by several
degrees east of the Green Mountains where current readings are
in the mid 30s to lower 40s. Several bands of rain will move
across the cwa this morning, but still anticipating a decrease
in areal coverage of precip this aftn as gusty southeast
downslope winds develop. Precip will become more trrn focused on
the southeast upslope side of the eastern dacks and portions of
the southern/central Greens. Additional bands of occasional
showers will become more widespread again this evening ahead of
boundary.

Water vapor shows maturing cyclone over the Ohio Valley with
development of full latitude trof across the eastern Conus. Good
moisture advection and associated lift associated with 925mb to
700mb waa will produce a 2 to 4 hour window of rain showers
this morning across our cwa. After initial band of precip exits
our northern cwa by 17z, expect more scattered trrn focused
precip to develop as southeast 925mb to 850mb wind fields
increase btwn 45 to 60 knots. Latest 00z guidance show deepening
low pres over the Eastern Great lakes will track ne with a
tightening sfc gradient anticipated as it encounters sfc high
pres over northern Maine. This will produce gusty southeast
downslope winds of 20 to 30 mph with localized gusts up to 50
mph along the western slopes. Thinking strongest winds with best
mixing will occur btwn 2 PM and 8 PM this evening. Also, expect
a secondary area of gusty winds across the northern slopes of
the dacks near Malone with isolated gusts btwn 40 and 45 mph,
just short of advisory criteria. The cool east/southeast flow
will help advect modified Atlantic air mass into eastern/central
VT, with temps mainly in the m/u 40s, while downslope sections
of the CPV/western dacks warm into the mid/upper 50s to near
60f.

Tonight, expect showers to redevelop along a sfc cold
front/occlusion as 985mb low pres lifts into southern Canada.
Latest RAP and HRRR show weak/narrow axis of some instability
with CAPE values of 100 to 300 j/kg, especially across the
southern SLV and western dacks, so would not be surprised of a
rumble or two of thunder. The combination of strong 5h energy
associated with developing negatively tilted mid/upper level
trof along with advection of pw values near 1.0, support the
idea of cat pops again overnight. Moderate to strong 925mb to
850mb caa develops on brisk westerly winds by 12z Saturday.
Expect lingering rain showers to switch to some snow showers
across the dacks, as 925mb to 850mb temps drop below 0c by 15z.
Some minor accumulation is possible above 1500 feet on Saturday
morning. Otherwise, expect a cold, cloudy, and raw Saturday with
rain and mountain snow showers likely thru most of the morning
hours. Some drier air develops late in the after with precip
become more trrn focused btwn 18z-21z. Highs range from near
freezing dack summits to mid/upper 30s greens to lower 40s slv
to mid/upper 40s cpv and lower ct river valley. Event total qpf
will range btwn 0.50 to 1.0 over the next 24 to 30 hours, which
will produce some sharp in bank rises on local streams and
rivers.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
As of 321 AM EDT Friday...Wrap around mountain showers will gradually
wind down Saturday night as the upper low and best moisture push
east of the area. Temperatures will drop into the lower to mid 30s,
with upper 20s possible in the Adirondacks and Northeast Kingdom.
Hence anticipate lingering rain showers could mix with/change to
snow late, mainly over higher elevations. Snow accumulations, if
any, would be minimal. Ridging and drier conditions briefly move in
early Sunday morning, but this will be short lived as yet another
shortwave brings showery conditions by afternoon. The bulk of the
precip will be across central and southern portions of our forecast
area, and given the system`s quick movement, don`t anticipate more
than a tenth of an inch of rainfall across much of the region.
Thickening cloud cover and cold air advection setting up in the
afternoon will keep temperatures down in the 40s, with a few spots
possibly peaking up above 50.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 321 AM EDT Friday...Lots of uncertainty through much of next
week, particularly from Tuesday onward. High pressure builds across
the area on Sunday night, cresting overhead Monday morning. It`s a
pretty cold airmass settling in, with 925mb temps progged to be -4C
to -8C by 12z Monday. Question is how much radiational cooling we
can get; clouds will decrease late Sunday night/early Monday, but
we`ll still be under a bit of a pressure gradient, especially in
eastern VT. Note that the MEX MOS continues to go quite cold,
especially in NY; 26/00z guidance says a low of 15 Monday morning at
KSLK. This is likely overdone, so have stayed close to the warmer
Euro MOS for temps. This gives Sunday night lows in the mid 20s to
lower 30s across the North Country. Monday will be dry with the high
slowly crossing the area. Uncertainty grows thereafter with the
longer- range guidance continuing to have any real model-to-model or
run-to- run consistency. Anticipate rounds of showers as a series of
shortwaves slide through the zonal flow aloft, but exactly where,
when, and how intense this precipitation will be is very much still
up in the air. Regardless, the cool and showery pattern looks to
persist through much of next week. Stayed close to a model blend for
Tue-Thu timeframe due to the uncertainty.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
Through 12Z Saturday...Aviation forecast will be challenging
over the next 12 to 24 hours. All taf sites start out at vfr
conditions this morning, but based on upstream obs expect some
mvfr cigs/vis in the heavier showers between 12z-16z. Conditions
will improve to vfr again, especially rut/btv and slk with
downslope winds. However, more precip redevelops this evening
with cigs trending toward mvfr. Breezy to gusty southeast winds
will develop at 15 to 30 knots with localized higher gusts
possible near Rutland this aftn. These winds associated with a
strong low level jet of 45 to 55 knots will create areas of
turbulence and wind shear, especially near complex terrain.
Winds threat diminishes overnight, as cigs lower to mvfr with
potential ifr cigs at mpv/mss and slk, as winds shift to the
southwest. Some rain/snow showers with vis around 2sm likely at
slk toward 12z Saturday.

Outlook...

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

&&

.HYDROLOGY...
As of 400 AM EDT Friday...Our latest forecast maintains
continuity suggesting widespread light to moderate rainfall will
affect the region on today into Saturday. Storm total rainfall
ending at 18Z Saturday should range from 0.50 to 1.0 inch. With
limited additional runoff input from snowmelt and the fact that
vegetative green-up will begin to absorb some of the rainfall
the threat of widespread stream/river flooding is not expected
at this time.

Lake Champlain remains in minor flood stage with levels generally
ranging from 100.6 to 100.7 feet as of 400 AM Friday. With
gusty south to southeasterly winds forecast on the lake today,
enhanced wave action and seiche effects will likely push levels
near or slightly above 101.0 feet (moderate flood level) across
northern lake waters for a period of time. As such, those with
interests in these areas should monitor the latest forecasts and
take appropriate action as necessary to protect property.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Wind Advisory from 1 PM this afternoon to 11 PM EDT this
     evening for VTZ016>019.
NY...None.

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Hastings
LONG TERM...Hastings
AVIATION...Taber
HYDROLOGY...JMG