Scientific Forecaster Discussion
fxus61 kbtv 221909
Area forecast discussion
National Weather Service Burlington Vermont
309 PM EDT sun Oct 22 2017
expect a continuation of above normal temperatures and dry
weather Monday as high pressure remains over the area.
Eventually a large upper level trough of low pressure will start
to approach the area Monday night and then move across the
north country Tuesday into Wednesday. As a result, clouds and
precipitation chances will be increasing with fairly widespread
rain expected Tuesday into Wednesday.
Near term /through Monday/...
as of 308 PM EDT Sunday...no significant changes for the
overnight forecast. Will once again see a wide range of
temperatures, ranging anywhere from the upper 30s in the
mountains to mid 50s in the larger valleys...and 40s everywhere
else. Should start to see a little better chance for fog over
On Monday...mid and high level moisture will be on the
increase. Highs will be in the mid 60s to lower 70s...which is
still well above normal. Not looking for any precipitation
during the day...but lower level moisture should start working
into parts of eastern Vermont as the day progresses.
Short term /Monday night through Tuesday night/...
as of 308 PM EDT Sunday...early portion of the work week
continues to look like the most active time period of the 7 day
forecast period, as strong high pressure off the eastern US
coast and a slow moving deep upper low and occluded front
combine to advect a deep sub-tropical plume of moisture into the
Monday night begins mild and dry with southerly flow increasing
along with mid/high clouds. This combination will keep min
temps will above normal, falling only into the mid 50s to low
60s. Towards sunrise, rain will begin to encroach into the St.
Lawrence Valley as deeper moisture associated with
aforementioned upper trough advances eastward. Widespread rains
shift into the Adirondacks during the mid-morning to early
afternoon hours, then further eastward into Vermont during the
evening rush hour and overnight.
The slow moving nature of the front combined with several waves
of low pressure moving along the boundary will support rainfall
amounts ranging from as little as a half inch in the St.
Lawrence Valley to as much as 2-3" in the southeast upslope
regions of the Adirondacks and eastern Vermont. Quantitative precipitation forecast in the
Champlain Valley and along the western slope of the Green
Mountains will largely depend on how south or southeasterly the
low level winds are, which speaking of, will likely trend quite
gusty late Monday night through Tuesday. The strongest winds
will primarily be ahead of the main precipitation shield, and
with mean 925mb winds around 40kts and near 60kt at 850mb,
expect gusts to likely be in the 30-40 mph range, limiting quantitative precipitation forecast
to perhaps 1-1.5". Overall, with such dry antecedent conditions,
the forecast rain shouldn't have any concerns to rivers, but
combine it with the wind and trees shedding leaves I wouldn't be
surprised to hear of some minor street flooding due to clogged
Long term /Wednesday through Sunday/...
as of 308 PM EDT Sunday...as the surface front pushes east of
the County Warning Area on Wednesday, showers will linger especially across the
eastern half of the region. Thursday sees an area of strong
energy diving from the northern plains into the base of the
upper trough across the eastern half of the US. This spawns
cyclogenesis along the frontal boundary to our south across the
mid Atlantic states. Models are in closer agreement that as the
new low swing though at the base of the negatively tilted
trough, showers will continue through Thursday, especially
across the eastern counties.
Atlantic high pressure moves back in at the end of the week for
a brief time bringing a couple days of quiet and dry weather
before the next surface boundary sits on our doorstep late
Saturday night into Sunday.
Temperatures for the long term will be in the upper 50s to mid
60s with overnight lows in the 40s.
Aviation /19z Sunday through Friday/...
through 18z Monday...VFR conditions are expected through the
period with only high level clouds expected. Winds will
generally be less than 10 knots. After 06z tonight can see some
clouds and fog developing over eastern Vermont and kmpv may see
MVFR to IFR ceilings and visibilities. Any fog that forms will
lift by about 13z once again.
Monday: VFR. Patchy fog.
Monday night: VFR. Breezy. Slight chance rain showers.
Tuesday: VFR/MVFR. Windy with gusts to 31 kts. Definite rain...chance rain showers.
Tuesday night: MVFR. Definite rain...likely rain showers.
Wednesday: VFR/MVFR. Chance rain showers.
Wednesday night: VFR/MVFR. Chance rain showers.
Thursday: VFR. Chance rain showers.
ktyx radar at Fort Drum, New York will remain down for
scheduled maintenance until further notice as technicians
repaint the radome.
Mpv is not transmitting due to a communications outage. FAA is
aware of the problem. We do not have an estimated return to