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Area forecast discussion
National Weather Service Burlington Vermont
337 PM EDT sun may 28 2017

we hope you were able to enjoy the nice day today because
conditions are going to change beginning on Memorial Day.
Widespread showers will move across the area during the day with
clouds keeping temperatures in the 60s. The showers end Monday
night...but another round of showers and some thunderstorms will
move across the area on Tuesday.


Near term /through Monday night/...
as of 337 PM EDT Sunday...relatively quiet weather is expected
tonight with generally partly to mostly cloudy skies. The clouds
are the result of flattening cumulus that struggled to get
organized today. Lows will generally be in the 50s. Looks like
the bulk of the precipitation is going to hold off until
Memorial Day.

Still looking at widespread showers to move across the area from
west to east on Memorial Day. Slower timing of precipitation
onset seems to be the trend with showers developing across
northern New York during the morning hours and across Vermont
from late morning into the afternoon. Plenty of clouds will
exist with highs generally in the 60s. Total rainfall on Monday
will generally be in the quarter to half inch range. At this
time it looks like the precipitation will come to an end during
the evening hours. However...the next chance of showers and
possibly a thunderstorm will move back in after midnight Monday
night with the best convective potential coming later on
Tuesday. See discussion below for details. Low temperatures will
generally be in the upper 40s to the mid 50s.


Short term /Tuesday through Tuesday night/...
as of 310 PM EDT Sunday...Tuesday continues to look
potentially active with the threat of numerous showers and
possible thunderstorms as several pieces of shortwave energy
embedded in southwest flow aloft rotate into the region
associated with broad upper level low pressure over central
Ontario. Latest GFS and NAM continue to show a modest 850mb
thermal ridge over the area ahead of these features, as well as
the potential for surface instability on order of 500-1000 j/kg
and impressive 0-3km and 0-6km shear of 30-40kts and 50-60kts
respectively. Uncertainly does lie in the timing of the
shortwaves moving through as the first looks to track through
central/western areas during the morning hours, which could
limit insolational heating and subsequent instability for the
afternoon when the second shortwave moves in. That said, will
continue to highlight likely pops for showers and increase to
chance coverage for thunderstorms, none of which I think will
have the potential to become severe.

Showers and any convective activity diminish going into the
overnight hours with a dry but mostly cloudy and mild night on
tap with lows mainly in the 50s.


Long term /Wednesday through Sunday/...
as of 310 PM EDT Sunday...extended period continues to look
unsettled as a broad mid-upper level trough will be our
controlling weather feature with persistent southwesterly flow
over the region. Extending from northern Ontario southward into
the Great Lakes beginning Wednesday, this feature very slowly
drifts eastward over the northeast through the week and into the
weekend, finally looking to exit into the Canadian Maritimes
Saturday night into Sunday. Several shortwave troughs rounding
the base of the parent trough will generate chances for
precipitation just about every day, with the best chances for
shower activity generally being during afternoon periods, where
the combination of relatively steep mid-level lapse rates and
surface heating will result in shallow instability and shower
development. Thursday looks to potentially be dry in-between
shortwave troughs, with the best day of the week coming Sunday
as a ridge of high pressure at the surface and aloft builds over
the northeast. Temps during the period look to be very
seasonal, with daytime highs in the mid 60s to low 70s, and
overnight lows in the mid 40s to low 50s.


Aviation /19z Sunday through Friday/...
through 18z Tuesday....VFR conditions through much of the period
with only increasing clouds above 5000 feet this afternoon and
tonight. Looks like main area of showers will move in from the
west after 12z and thus the 12z to 18z period will see ceilings
and visibilities lowering into the MVFR category. Winds will be
under 10 knots through 12z then gust to 20 knots from the south
and southeast after 12z.


Monday night: VFR. Slight chance rain showers.
Tuesday: VFR. Breezy. Likely rain showers...chance thunderstorms and rain.
Tuesday night: VFR. Chance rain showers.
Wednesday: VFR. Chance rain showers.
Wednesday night: VFR. Chance rain showers.
Thursday: VFR. Chance rain showers.
Thursday night: VFR. Chance rain showers.
Friday: VFR. Chance rain showers.


winds will be increasing tonight from the south and reach the 15
to 25 knot range after midnight. Thus a lake Wind Advisory has
been issued. These winds will create rather choppy conditions
and the stronger winds are expected on Memorial Day and should
continue right into Tuesday.


Btv watches/warnings/advisories...
New York...none.


near term...evenson

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