Scientific Forecaster Discussion
fxus61 kbtv 261817
Area forecast discussion
National Weather Service Burlington Vermont
217 PM EDT sun Mar 26 2017
high pressure over the north country will give way to unsettled
and warmer weather 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 1114 am EDT Sunday...no significant changes for this mid
morning update. Precipitation still not very impressive moving
across central New York. Previous discussion follows.
Freezing Rain Advisory in effect for portions of the north
A relatively quiet day is on tap for the north country to end
the weekend as high pressure centered over eastern Quebec
continues to provide mainly sunny and dry conditions to the
region. We'll see some increasing mid/high clouds through the
day with chances for precipitation increasing from the southwest
beyond the 4pm hour and heading into this evening. Highs will
run slightly below normal for late March in the mid/upper 30s to
around 40 in the Champlain Valley.
For tonight into Monday, concerns remain from the previous
forecast thinking in regards to freezing rain potential as deep
low pressure north of the Ozarks this morning will push a warm
front from southwest to northeast into the forecast area
tonight. 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.
Short term /Monday night through Tuesday/...
as of 356 am EDT Sunday....shortwave trough moves out of the
area Monday night and with best dynamic forcing now east of
US...areal coverage of precipitation should decrease rapidly.
Some lingering showers near the Canadian border through the
first part of the night will exist and that should be about it.
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.
Long term /Tuesday night through Saturday/...
as of 356 am EDT Sunday...rain will decrease in areal coverage
from west to east Tuesday night as shortwave trough moves east
of the area. Colder air will begin to filter in and any
lingering precipitation will turn to snow showers. Northwest
flow aloft develops on the backside of the trough Wednesday and
Wednesday night and looking for some mountains snow showers in
this pattern. Drier air begins to move in Thursday and Friday
for no precipitation. Unfortunately data all over the place
heading into the weekend with timing of systems and have kept in
the chance for showers Friday night into Saturday. Highs on
Wednesday and Thursday will be in the upper 30s to mid
40s...then in the 40s for Friday and Saturday.
Aviation /18z Sunday through Friday/...
through 18z Monday...mainly VFR conditions expected through 00z
Monday, as a ridge of high pressure moves off the New England
coast by 00z Monday. Composite radar loop at 18z Sunday showing
some weak returns over the region, but surface observations
showing most of this activity not reaching the surface at this
time due to the lower portion of the atmosphere being fairly
dry at this time. A warm front will approach the region later
tonight with areas of light rain developing, with areas of
freezing rain east of the Green Mountains, especially at kmpv.
Expecting conditions to lower to MVFR/IFR between 03z-07z Monday
and continuing through 18z Monday. Expecting any freezing rain
across the region to change to plain rain by 15z Monday.
Outlook 18z Monday through Friday...
18z Monday through 00z Tuesday...rain with cigs/vsby variable
from IFR to MVFR.
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 northwest
winds likely Wednesday.
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.
Vermont...Freezing Rain Advisory from 7 PM this evening to 11 am EDT
Monday for vtz003-004-006>008-010-012-016>019.
New York...Freezing Rain Advisory from 7 PM this evening to 11 am EDT
Monday for nyz034.