Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 262345
Area Forecast Discussion
National Weather Service Burlington VT
745 PM EDT Sun Mar 26 2017
Unsettled and warmer weather moves into the North Country for
tonight and Monday as developing low pressure over the central
U.S. pushes a warm front northward through the region. Periods
of freezing rain tonight into Monday will transition to all rain
by Monday afternoon, briefly tapering off Monday night before
returning for Tuesday and ending as snow Tuesday night.
.NEAR TERM /THROUGH MONDAY/...
As of 716 PM EDT Sunday...Several adjustments to pop/temps and
precip type grids based on current obs and latest radar trends.
Large scale pattern shows elongated cyclonic circulation over
the Great Lakes with several ribbons of enhanced moisture moving
across our CWA this evening. This moisture has produced very
light rain with some mix of sleet across our region...but most
precip is having difficulties reaching the ground...given very
dry low levels. Thinking after next band across the central CPV
and southern VT lifts north of cwa by 02z with most of the
region remaining dry this evening. Better lift and deeper
moisture arrives from southwest to northeast across our cwa
after 06z tonight...and have tried to refresh pops to show this
scenario. In addition...I have reduced the areal coverage of
freezing rain this evening as almost all obs are above 32F...and
highway pavement temps are running between 35 and 42F.
Expecting surface temps to fall below 32 in protected valleys
and mid slopes east of the spine and parts of essex county ny
between 02z and 07z. When additional moisture arrives...areas
of freezing rain looks reasonable. Still watching the SLV
closely as MSS is 33 with northeast winds...and potential for
some pockets of freezing rain. Temps are currently running 2 to
4 degrees warmer than expected...so have integrated this change
into the hourly obs.
Previous discussion below:
Better slug of moisture with deeper saturation will move into
the area after 6z. Warm air aloft continues to push into the
area and temperatures have risen into the mid to upper 30s
across our area. Temperatures will not drop too far overnight
with clouds and precipitation moving into the area, as well as
warm air advection with warm front lifting across the area.
Still concerns across the Eastern Dacks and Eastern Vermont for
freezing rain and headlines for freezing rain advisory remains
For tonight into Monday, concerns remain from the previous
forecast thinking in regards to freezing rain potential as deep
low pressure pushes a warm front across the area. Thermal
profiles are as such that freezing rain will be the dominant
ptype across Essex County of New York and from the western
slopes of the Green Mountains eastward where surface temps will
hover a freezing or just below as warmer air aloft moves over
the area. In the deeper Champlain and St. Lawrence Valleys
surface temps remain in the low/mid 30s overnight so while
pockets of freezing rain are certainly possible, the overall
impacts will be minimal. On the impact side of things, under the
advisory area, there is some concern that impacts will be on
the low side through much of the event as modeled road
temperatures show surfaces warming well above freezing during
the day, and only right to freezing during the overnight. The
expected ice accumulations won`t have an impact on powerlines as
only up to a tenth of an inch is expected at the lower
elevations, and even though higher up on the mid-slopes
increased amounts could accumulate onto the larger transmission
lines, they can usually handle a little more without failing.
Freezing rain will be falling during the Monday morning commute
though so any ice on area roadways will be a concern.
By mid-day Monday the warm front pushes closer to the Canadian
border allowing surface temps to warm into the mid-30s east to
upper 40s west transitioning ptype to plain rain and ending the
threat of ice accumulation. Rain will be ending by about 00z
across our entire forecast area.
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 301 PM EDT Sunday....Monday night will be a brief break
in precipitation with mainly dry conditions expected. Next
shortwave trough moves into the region Tuesday afternoon and
once again widespread precipitation should develop over northern
New York and Vermont. High temperatures on Tuesday will be in
the mid 40s to lower 50s...thus expecting precipitation to fall
in the form of rain. Another ridge of high pressure will build
southward from Canada Tuesday night and precipitation ends as
colder air moves back into the North Country. Tuesday night
temperatures drop back into the 20s and lower 30s. Any lingering
precipitation will change to snow showers before ending.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 351 PM EDT Sunday...The north country will be under cold
advection on Wednesday with a slight chance for some rain or
snow showers, with the best chance for any precipitation on
wednesday will be mainly over the Adirondacks and Green
Mountains. A ridge of high pressure will build south from Canada
on Thursday and remain through early Friday, with fair and dry
GFS model has now trended toward the ECMWF model solution for
Friday and Saturday. Will keep most of Friday dry across the
region, except for slight chance pops for New York state and
southern Vermont. ECMWF take a low up through the eastern Great
Lakes on Friday, while the GFS model has this low further south.
Both models develop a secondary low pressure area off the New
Jersey coast late Friday night and early Saturday. The ECMWF has
this low a bit further north. Have stuck with superblend pops
for Friday night and Saturday and will have a chance of rain or
snow in the forecast.
Forecaster confidence is lower for Sunday forecast as 12Z runs
of GFS and ECMWF hinting at a dry forecast. Have stuck with
superblend pops for Sunday with a chance of rain or snow
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --Through 00Z Tuesday...Warm front approaches the region as the
mix of borderline VFR/MVFR ceilings will continue to deteriorate
as the night wears on. Bands of rain are starting to move
through and will become more widespread after 03Z. Conditions
will continue to drop as freezing rain across KMSS/KSLK/KMPV
during the overnight hours before returning to rain by mid
morning. Ceilings will continue to degrade to MVFR/IFR by 20Z
with KMSS seeing closer to IFR/LIFR.
Winds will start out of the south-southeast at 05-10 knots
before increasing to 10-20 knots after 03Z before returning to
05- 10 knots after 20Z. KMSS will be the exception with winds
out of the northeast at 05-10 knots. KSLK could also see a
couple hours of wind shear at 09Z at 2000 feet from the
southwest at 35 knots.
Outlook 00Z Tuesday through Friday...
00Z Tuesday through 00Z Thursday...MVFR/IFR in scattered rain
showers Monday night, becoming prevailing rain Tuesday, and
rain/snow Tuesday night and Wednesday. Moderately gusty NW winds
00Z Thursday through 00Z Saturday...Mainly VFR, except for some
scattered snow showers over the Adirondacks and Green
Mountains, mainly 00Z Thursday until 00Z Friday.
-- End Changed Discussion --
VT...Freezing Rain Advisory until 11 AM EDT Monday for VTZ003-004-
NY...Freezing Rain Advisory until 11 AM EDT Monday for NYZ034.