Area Forecast Discussion
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FXUS61 KBTV 220811
Area Forecast Discussion
National Weather Service Burlington VT
411 AM EDT Sat Oct 22 2016
An upper level trough of low pressure continues to become
negatively tilted, keeping frontal boundary and associated surface
low pressure system over the region through Saturday night/early
Sunday. As the system moves past, colder air will filter in
bringing with it northwest flow producing upslope rain and snow
showers in higher elevations from early Sunday morning through
Tuesday. Another surface low pressure system looks to affect the
Northeast Thursday and into Friday.
.NEAR TERM /THROUGH SUNDAY/...
As of 158 AM EDT Saturday...Light rain and drizzle plague most of
the North Country with low clouds and N-NW flow this morning. More
moisture and persistent rain expected to affect the region this
afternoon and evening with enhancement over the terrain in the NW
flow as the surface low move into northern Maine. Noticeably
cooler temperatures to start the weekend as we move into he
backside of the surface low.
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 411 AM EDT Saturday...The region will remain under cyclonic
flow through the period, as a surface low pressure area remains
over Quebec. Have gone with a dry forecast for Sunday night, as
mos pops are low. On Monday, forecast area remains under cold
advection, with models hinting at some orographic rain and snow
showers over the Adirondacks and Green Mountains for Monday and
Monday night. Have gone with slight chance pops in these areas for
Monday and Monday night. Have kept valley areas such as the
Champlain and Saint Lawrence valleys dry through the period.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 411 AM EDT Saturday...The region will still remain under
cyclonic flow Tuesday and Wednesday. Will continue with slight
chance pops for orographic rain and snow showers over the
Adirondacks and Green Mountains for Tuesday and Wednesday.
Wednesday night, a high pressure area will build into the region
from the Great Lakes with fair and dry weather expected across the
north country. Models showing some differences on Thursday, with
the GFS model keeping the weather dry all day, as a ridge of high
pressure will be over the region. GFS model also suggesting dry
weather will continue into Thursday night and Friday as well.
However, the ECMWF model starts Thursday off dry across the
region, but brings rain showers ahead of a warm front into
northern New York Thursday afternoon, mainly across the
Adirondacks and Saint Lawrence valley, while the Champlain valley
and Vermont remain dry on Thursday. Have adjusted superblend pops
to the ECMWF timing, and will bring in showers to northern New
york Thursday afternoon. Much like the GFS, the ECMWF model has
trended slower with bringing in showers to the region on Thursday.
Have gone with superblend pops for Thursday night and Friday,
given model differences. Thus, will have a chance of showers in
the forecast for Thursday night and Friday, per the ECMWF model.
.AVIATION /08Z Saturday THROUGH Wednesday/...
Through 06z Sunday...Widespread LIFR and IFR persist through the
morning hours. Expect conditions to gradually improve to MVFR/IFR
during the early afternoon but with rain/rain showers persisting
throughout the period.
Winds out of the NW shift more westerly late today at 8-16kts.
Gusts develop this evening at 17-27kts.
Outlook 06z Sunday through Wednesday...
06z Sunday through 00z Monday: A prolonged period of unsettled
conditions is expected with widespread MVFR/IFR in periods of
00z Monday through 00z Wednesday: A mix of VFR/MVFR with upslope
showers in NW flow.
00Z Wednesday through 00Z Friday: IFR/MVFR fog development
As of 315 PM EDT Friday...Through early this afternoon the heaviest
rainfall has been located over the Saint Lawrence Valley and
Northern Dacks (1 to 3.5 inches)...the amounts tapering off
sharply with < 0.75 inch across the central/southern Champlain
Valley and most of VT. Moving forward thinking additional rainfall
will range between 1 and 2 inches with some isolated higher
amounts along the western dacks possible. Several periods of rain
still anticipated for VT...as system tracks along the coast and
Atlantic moisture is advected back into the region tonight. Given
the long duration and breaks in the precip intensity/coverage...we
are not anticipating any hydro related issues associated with this
event. However...some minor urban and street flooding is possible
associated with the heavier rainfall rates through Saturday with
leaves clogging storm drains. Otherwise...some modest rises in
local rivers and streams are likely this weekend...but no
widespread flooding is anticipated.