437
FXUS61 KBTV 220609
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
209 AM EDT Mon May 22 2017

.SYNOPSIS...
Rain will taper off west to east across the north country during
the pre-dawn hours. Lighter rain showers and overcast skies
will linger today, resulting in relatively cool temperatures.
Dry conditions return on Tuesday with a brief period of surface
high pressure, before another low pressure system brings more
rain for the end of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 AM EDT Monday...Ended rain west to east much more
quickly with this update as radar trends showing back end of
precip moving into western NY state, and high resolution model
reflectivity showing it as well. Updated grids with a mix of the
model reflectivity which has a dry period mainly this morning.
Another area of scattered showers are possible this afternoon as
a final weak shortwave trough moves through the region to
finish things off. Also backed off QPF with the rain ending
earlier. No changes to temps/winds/sky with this update.

Best large-scale forcing slides to our east between 12-15Z
Monday, but NAM RH profiles indicate continued saturated
conditions in 950-850mb layer, and skies will generally remain
cloudy with low overcast in place. The low-level inversion
layer in place will keep sfc temps cool, despite 850mb thermal
ridge in place (+10C to +11C) across nrn NY. Sfc high temps
generally low- mid 50s east of the Greens, upr 50s in the
Champlain Valley, and upr 50s to lower 60s across nrn NY.
Maintained a chance of showers Monday afternoon. There is some
indication of a trailing sfc trough/convergence line moving ewd
across nrn NY into VT late in the afternoon, which may result in
an additional period of (brief) rain shower activity.

A weak sfc ridge builds newd into our region from western NY
Monday night. This results in lowering inversion layer and light
near-sfc winds. With moist soils, will see combination of
abundant low clouds and patchy fog areawide. Moist layer is
quite shallow, so not anticipating any precipitation. Lows
Monday night mainly 43-48F.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As of 339 PM EDT Sunday...The short term looks to be the quiet
intermission between the unsettled periods of the near and long
term. After the passage of a cold front and associated trough, a
weak ridge moves in, leaving Tuesday looking like a dry and fair
day across the region. Winds will remain west-southwesterly
behind the front so little change in the air mass leads to
warmer temperatures than just prior to frontal passage with
highs in the upper 60s and low 70s. Gradual increased cloud
cover moving in from the west Tuesday night ahead of the next
system will lead to low temperatures low 50s in the western
counties and 40s in the eastern half.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 339 PM EDT Sunday...The long term pics up again in
activity as multiple systems will impact the area through to
the weekend. A coastal low moves northeast into New England. The
GFS and ECMWF still disagree on the inland advection of the
precipitation with the GFS keeping it mostly offshore while the
ECMWF being more aggressive and extended the precip into
Southeast VT. For now have just kept chance PoPs east of the
Greens for Wednesday.

Thursday has a positively tilted upper trough associated surface
low over Ohio Valley with a closed off upper low. The low
progresses slowly to the northwest of the CWA before shifting
west over the northern counties. This leads to and extended
period of unsettled conditions and potential for precipitation
from midday Thursday and through midday Friday as low pushes out
to the coast. Lingering showers in the higher terrain remains
in the resulting northwest flow through to early Saturday
afternoon. The second half the weekend sees a high pressure
ridge begin to build back in leading to a brief return to fair
conditions.

High temperatures in the long term will range from the upper 60s to
upper 70s, while lows will be in the 40s to 50s.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Through 00Z Tuesday...Rain ending west to east but little effect
on flight categories with most visibilities and cigs VFR.
Ceilings to gradually lower to MVFR throughout the day, even as
rain dissipates low level moisture remains trapped below the
subsidence inversion under building high pressure aloft. low
level winds become gusty during the day out of the south with
gusts into 20-25kt range.

Outlook...

Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA.
Wednesday Night: VFR. Chance SHRA.
Thursday: VFR. Chance SHRA.
Thursday Night: VFR. Likely SHRA.
Friday: VFR/MVFR. Likely SHRA.

&&

.MARINE...
As of 231 PM EDT Sunday...A Lake Wind Advisory is in effect
starting at midnight (04Z Monday). Gradient flow increases out
of the south during the pre- dawn hours Monday, with sustained
winds over Lake Champlain reaching 15-25kts after midnight and
waves building to 2-4 feet. The highest waves are expected
across the northern portion of the broad lake south of Grand
Isle. South winds will remain generally in the 15-25kt range
during the daylight hours on Monday, before diminishing Monday
evening.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Hanson
NEAR TERM...Hanson
SHORT TERM...MV
LONG TERM...MV
AVIATION...Hanson
MARINE...Team BTV