Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
1033 am EDT Thursday Sep 3 2015
an upper level disturbance and weak surface cold front will move
south across the north country today...along with scattered showers
and isolated thunderstorms. Thereafter...a deep layer ridge will
return to the region. Temperatures will be closer to seasonal
averages on Friday with lower humidity...but the overall trend will
be toward very warm...moderately humid...and mainly clear conditions
for the Holiday weekend.
Near term /until 8 PM this evening/...
as of 1022 am EDT Thursday...not much change to the previous
forecast. Latest visible/infrared scans show variable cloud cover across the
region and a few showers developing. With the weak forcing
convection will be tricky today as instability increases. Don't
expect any significant storms today but the showers that do
develop will pulse up fairly quickly given no shear and decent
forecast instability. Applied some cosmetic changes to temperatures and
dew points and that was it.
Previous discussion as of 723 am edit Thursday...middle level flow
becomes a bit more northwesterly today. This will allow for weak
shortwave trough and associated cold front to drop south across
forecast area. There were a few passing showers and even a
thunderstorm or two over northern areas overnight...but radar is
rather quiet at this time. Despite variable amounts of cloud
cover...fog has formed in many of the favored locales...but should
be lifting or dissipating by middle morning. With daytime
heating...expect to see an increase in coverage of showers and a
few thunderstorms as front makes its way south across forecast
area roughly between 14z and 20z. Highest probability of precipitation (40-50%) indicated
across southern half of forecast area. Behind the front...will see
a slightly cooler air mass with northerly winds around 10 miles per hour
developing this afternoon...along with clearing conditions. High
temperatures will be generally in the lower to middle 80s. Noticeable
drop in dewpoints doesn't occur till tonight.
Short term /8 PM this evening through Saturday/...
as of 430 am EDT Thursday...high pressure brings fair and tranquil
conditions tonight...with fog expected in the favored locations
06-12z Friday along with low temperatures mainly in the 50s...except for
some upper 40s in the Adirondacks. High pressure settles over
forecast area on Friday...allowing for an abundance of sunshine.
Temperatures will be slightly cooler...although still a few degrees above
normal with readings in the upper 70s and lower 80s along with
comfortable humidity levels. Deep layer ridge anchored over the
north country Thursday night and Friday. Expect clear skies with
some late night fog once again. Min temperatures Friday night mainly in
the 50s once again...except for some upper 40s in the normally
cooler spots in the Adirondacks and Northeast Kingdom. Temperature
profile slightly warmer Saturday...so look for maximum temperatures in the
lower to middle 80s.
Long term /Saturday night through Wednesday/...
as of 345 am EDT Thursday...apex of an upper ridge and surface
high over the north country for the first half of the weekend
begins to drift south/southeastward Saturday night to the Middle-
Atlantic States by Sunday. This will allow the middle-level flow to
turn more zonal going into the early part of next week, but the
resulting weather will continue to be sunny/dry conditions through
Monday with highs running a good 10-15 degrees above normal in the
80s to near 90. Lows will be a bit closer to normal, but still on
the mild side in the upper 50s to middle 60s. Global models continue
to show increasing chances for precipitation Tuesday and Tuesday
night as a weak shortwave trough and surface frontal boundary
track across the area. Latest trends though are for a very thin
line of deeper moisture with little height falls so thinking this
really won't amount to much.
Behind the front, surface high and upper ridge become re-established
over the northeast though with less amplitude so temperatures do drop of a
little going into Wednesday and Wednesday night. Still looking to be
above normal though, but only by 5-10 degrees with highs in the
upper 70s to middle 80s and lows in the 50s to low 60s.
Looking out further in the forecast, it appears there may be a
better chance for showers and thunderstorms late Wednesday night
through Thursday as a more potent upper trough and surface cold
front track from the Great Lakes through the northeast. Certainly
way too far out to zero in on the exact details, but a return to
more normal temperatures looks possible towards the end of next week.
Aviation /15z Thursday through Monday/...
through 12z Thursday...variable flight conditions from vlifr to
MVFR will continue into the middle-morning hours before fog and low
stratus lift into a scattered-broken VFR deck. Thereafter, a surface front
shifting through will bring some widely scattered showers and
possible thunderstorms and rain to the area this afternoon, mainly south of a line
from kslk to kmpv though conditions will largely remain VFR. Brief
reductions in ceilings/visibility are possible in any rain. Any convective
activity will diminish after sunset with another night of MVFR/IFR
Outlook 12z Thursday through Monday...
mainly VFR. Late night and early morning vlifr/IFR ceilings/visibility
likely at mpv/slk, and possible at mss.