Scientific Forecaster Discussion
fxus61 kbtv 140819
Area forecast discussion
National Weather Service Burlington Vermont
319 am EST Thu Nov 14 2019
warmer weather is on the way as high temperatures across much of the
north country will warm near or above freezing both today and again
on Friday. A strong Arctic cold front will move through the region
Friday afternoon and evening and could produce some strong
convective showers and snow squalls. An even colder air mass will
descend upon the region behind this front with record lows expected
again on Friday and Saturday night. This cold snap will be short-
lived with temperatures warming back to near normal values through
the beginning of next week.
Near term /through Friday/...
as of 318 am EST Thursday...based on recent surface observations and
satellite analysis, a warm front is currently draped across southern
St. Lawrence County and extends southeastward toward Saratoga
Springs, New York. Weak isentropic lift ahead of this frontal boundary is
allowing for some light snow showers to develop out ahead of this
front. Radar echoes across northern New York continue to increase
this morning as the isentropic lift couples with some weak moisture
advection. This should allow scattered shower activity to continue
through the morning hours and possibly into the afternoon depending
on how the front becomes oriented this afternoon. Snowfall
accumulations associated with this feature should remain less than
an inch as the overall synoptic set-up isn't the most favorable
given weak dynamics other than the isentropic lift.
Otherwise, we will see a little relief from the record cold snap
across the north country as warm air advection behind the warm front
should allow temperatures to warm into the lower 30s. The plentiful
cloud cover observed this morning will continue throughout the day
as we continue to increase our mid-level moisture. For the Champlain
Valley, the warmer temperatures will unfortunately be coupled with
gusty winds developing by late morning. As the pressure gradient
becomes increasingly north to south oriented, we should see winds
channel up through the valley with gusts up to 25 mph possible. This
will make it feel quite colder than it actually is but these gusty
winds will quickly dissipate this evening. Temperatures tonight will
also be on the mild side thanks to continued warm air advection and
abundant cloud cover. Lows will only drop into the lower 20s to
upper 20s which is about 10-12 degrees warmer than this morning
(still several degrees below normal though).
The warm-up will be rather short-lived with an even strong Arctic
cold front expected to move through the region Friday afternoon and
evening. Ahead of the front, however, we should see temperatures
warm into the lower to upper 30s. High resolution models continue to
confirm our thinking of convective snow showers and snow squalls
ahead of the cold front Friday afternoon and evening. The best
chances for snow squalls remain across northern New York due to the
favorable timing and stronger frontogenesis and convergence. The
timing of these showers/squalls could likely impact the evening
commute across portions of New York as the squalls won't move into
Vermont until Friday evening. A quick burst of snowfall coupled with
gusty winds up to 30 mph will create white-out conditions in any
locations that see squalls Friday afternoon. Drivers should be aware
and be ready to take appropriate actions should they experience one
of these squalls.
Short term /Friday night through Saturday night/...
as of 318 am EST Thursday...the main story for the end of the week
will be cold. The aforementioned cold front and any associated
squalls will rapidly push south across the region early Friday
night, ushering in a much colder and drier airmass. Temperatures
will plummet, with 925mb temps approaching -16c by Saturday morning.
Lows will be in the single digits across most spots, with some
negative numbers possible in the usual cold locations in the
northern Adirondacks. Saturday will be sunny but quite cold as high
pressure crests overhead. Highs will range from the upper teens to
mid 20s, warmest in our southern sections. Saturday night will be a
few degrees colder than Friday.
Long term /Sunday through Wednesday/...
as of 318 am EST Thursday...the first part of next week looks fairly
quiet with some relief from the bitter cold. High pressure squatting
across New England will keep deepening low pressure moving off the
East Coast shunted to our south Sunday and Sunday night. Uncertainty
grows thereafter as models diverge in the handling of an upper
trough approaching from the west and a series of shortwaves rotating
around it. The differences only grow in time; by the middle of the
week, the European model (ecmwf) has a 975mb low off the southern New England coast
with a closed-off upper low, while the GFS has an open wave aloft
with just weak low pressure well south of Nova Scotia. Given the
wide range of solutions, have stayed with a model blend for now. It
does at least look like we should see a warming trend through the
early part of next week. Highs will be around 40 Tuesday/Wednesday,
and while this is still a few degrees below seasonal normal, it will
be welcome after the chilly end to this week.
Aviation /08z Thursday through Monday/...
through 06z Friday...VFR conditions with light winds will
persist through the afternoon hours on Thursday. Developing
shower activity north of Lake Ontario will drift east into the
St. Lawrence Valley and could bring some light snow showers to
kmss between 08z and 10z. Have included a tempo ground in the
latest package to account for reduced visibilities and ceilings
as the surface begins to saturate over the next few hours.
Localized gusty winds will develop over the Champlain Valley in
response to the winds shifting to the south, so have also
included a mention of winds gusting up to 20 knots at kpbg and
kbtv this afternoon.
Friday: mainly VFR, with local MVFR possible. Chance shsn.
Friday night: VFR. No sig weather.
Saturday: VFR. No sig weather.
Saturday night: VFR. No sig weather.
Sunday: VFR. No sig weather.
Sunday night: VFR. Slight chance shsn.
Monday: VFR. Slight chance shra, slight chance shsn.