Scientific Forecaster Discussion
fxus61 kbtv 181900
Area forecast discussion
National Weather Service Burlington Vermont
300 PM EDT Wed Sep 18 2019
strong high pressure will dominate regional weather conditions
through Sunday with fair and dry weather expected. Mild to warm
afternoon highs and seasonably cool overnight lows will be the
rule with generally light winds. The next chance of showers
arrives by Sunday night into Monday with the approach of a cold
Near term /through Thursday night/...
as of 300 PM EDT Wednesday...chamber of Commerce weather
continues this afternoon under deep layer ridging bridged across
the northeastern quarter of the nation. Over the next 42 hours
the 500 mb ridge axis will essentially pivot atop the region
with broad-scale subsidence leading to mostly clear skies and
mainly light winds. Patchy late night mist/fog will continue to
be prevalent in favored valleys/hollows in the late night to
early morning hours. Given the dry nature of the airmass
slightly larger than normal diurnal temperature swings will also
occur through the period. With tonight's lows ranging from the
upper 20s to mid 30s across the dacks and eastern Vermont frost
headlines are now in effect for these areas. Milder readings in
the upper 30s to lower 40s are expected for the broader St.
Lawrence and Champlain valleys. On Thursday a nice rebound will
occur with readings topping out in the upper 60s to lower 70s.
Somewhat milder overnight lows will occur by Thursday night as
airmass moderates somewhat leading to a considerably lower
threat of frost.
Short term /Friday through Friday night/...
as of 300 PM EDT Wednesday...deep layer ridging will bring yet
another beautiful late Summer day to the north country on
Friday. With the main axis of the upper level ridge to our west,
it's looking like we could see some moisture work it's way
across the periphery of the ridge and into the region Friday
morning. This could bring some mid to high clouds into the area
throughout the day on Friday but should only be about 20-30
percent sky coverage. We are still looking at afternoon high
temperatures in the mid to upper 70s but temperatures may need
to be tweaked down a degree or two in coming days if greater
cloud coverage is expected. These increasing clouds and warm air
advection will limit cooling Friday night into Saturday with
lows only dropping into the lower to upper 50s.
Long term /Saturday through Tuesday/...
as of 254 PM EDT Wednesday...the warming trend continues into
this weekend with the upper level ridge axis shifting over the
north country on Saturday before beginning to slide eastward
late on Sunday. This should allow temperatures to warm into the
mid to upper 70s again on Saturday with a few places likely
flirting with 80 degrees. By Sunday, however, we should see
pretty widespread 80 degree readings with highs generally in the
upper 70s to mid 80s. Cloud cover will increase throughout the
day on Sunday as moisture streams into the region ahead of a
cold front barreling towards the north country. With the ridge
axis shifting offshore, a deep upper level trough will work
toward the region on Monday. This will help drive a cold front
through the region and bring US our first chance in rainfall in
over a week. Rainfall amounts with this system should be pretty
meager, averaging less than a quarter of an inch, with the bulk
of the upper level dynamics and forcing well to our north. To
top it off, a 25-30 knot 850 mb jet could create a rain shadow
over the Champlain Valley to produce even less rainfall.
Rainfall associated with the cold front will taper off through the
overnight hours with another ridge expected to slide back into the
region on Tuesday. Temperatures will return to seasonal normal with
highs in the mid 60s to around 70 for the first half of next week.
The flow does become more progressive and less amplified next week
which should hint at a few more chances of rainfall but no major
warm-ups or cool-Downs. Long story short, it's going to be a great
period of weather over the next week so enjoy it while you can.
Aviation /19z Wednesday through Monday/...
through 18z Thursday...mainly VFR/sky clear through the forecast
period under deep layer high pressure. Winds generally light
north to northeasterly at 8 kts or less through 00z, trending
near calm overnight through mid-morning on Thursday. Only issue
will be patchy IFR/LIFR br/fg at kmpv and kslk in the 0530-1330
time frame Thursday.
Thursday night: VFR. Patchy br.
Friday: VFR. Patchy br.
Friday night: VFR. No sig weather.
Saturday: mainly VFR, with local MVFR possible. No sig weather.
Saturday night: VFR. No sig weather.
Sunday: VFR. No sig weather.
Sunday night: mainly VFR, with local MVFR possible. Chance rain showers.
Monday: mainly MVFR, with local IFR possible. Chance rain showers.
Vermont...frost advisory from midnight tonight to 9 am EDT Thursday for
Freeze warning from midnight tonight to 9 am EDT Thursday for
New York...frost advisory from midnight tonight to 9 am EDT Thursday for