FXUS61 KBTV 091753
Area Forecast Discussion
National Weather Service Burlington VT
1253 PM EST Sun Dec 9 2018
A couple of upper level disturbances will move across the North
Country through the middle of the week, but they will only bring
light snow showers to the area. Otherwise relatively dry weather is
expected for much of this week. Temperatures will remain below
normal through Wednesday, then a gradual warming trend is
anticipated. The next chance for significant precipitation arrives
.NEAR TERM /THROUGH MONDAY/...
As of 932 AM EST Sunday...Just some slight adjustments to
timing of temperatures and sky cover to match surface and
satellite observations. Despite cloud cover across the Northeast
Kingdom of Vermont, many locations dropped below zero last
night, so slowed warming from forecast to account for these cold
temperatures...these locations should still warm into the mid
20s today. Additionally, some flurries have been picked up on a
few surface observations across the Northeast Kingdom so have
added this to forecast until 17z, after which light snow is
expected to continue as our next shortwave moves down from
No significant changes needed this morning. Winds have started
to turn to the south at some sites, including the the St
Lawrence Valley and Adirondacks, which has allowed lake enhanced
moisture to begin shift back north. There are some light
returns showing up on radar, and surface obs/webcams indicate
some light snow showers or flurries in these areas. Have made
some slight adjustments to PoPs to match these trends, and to
sky cover as well to match latest satellite. Overall the
forecast is in good shape and no other changes were needed.
Another round of light snow is expected today into tonight as a
shortwave skirts by just north of the international border. A
weak warm front will lift across the North Country today out
ahead of this system, turning winds to the southwest and
ushering in milder temperatures. Some light snow will move into
the southern St Lawrence Valley and western Adirondacks this
morning as the shifting flow lifts lake enhanced moisture into
the area, but the bulk of the activity will hold off until later
this afternoon and evening as the shortwave moves by. Moisture
will be limited and the best dynamics will remain north of the
border, so precipitation will be light and mainly focused in the
northern mountains. Snow amounts through this evening should be
an inch or less, perhaps a bit more at higher elevations.
Southwest winds will become gusty this afternoon as a jet swings
around the approaching trough. Gusts of 25-30 mph will be
possible, particularly in the St Lawrence and Champlain Valleys.
Highs today will be warmer but still a bit below normal, in the
mid 20s to mid 30s. Snow will come to an end overnight as high
pressure builds across the North Country, bringing a reinforcing
shot of colder and drier air. Tonight`s low temperatures will
be in the teens to around 20, though would not be surprised to
see some single digits in a few spots where breaks in cloud
cover occur. Monday will see a mix of sun and clouds and highs
back down into the teens and 20s.
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 315 AM EST Sunday...Surface high pressure will prevail
across the North Country during the short-term period, providing
light winds and temperatures near to slightly below seasonal
norms for mid-December. While no significant precipitation is
expected during the short-term period, with weakly cyclonic
flow regime persisting aloft, and a weak sfc low across the
northern Great Lakes and sern Ontario, will see low-level wswly
trajectories from Lake Ontario bringing chances for lake-
induced snow showers, mainly Tuesday and Tuesday night, along
with abundant cloud cover. PoPs range from 20-40%, with the
highest PoPs centered across the northern Adirondacks for snow
showers Tuesday afternoon into Tuesday evening. A light dusting
to 1" of snowfall is possible across St. Lawrence into Franklin
NY counties late Tuesday. In terms of temperatures, anticipate
lows in the single digits above zero to low teens on Monday
night, with highs in the low- mid 20s for Tuesday. May see some
weak low- level CAA with a shallow reinforcing surge of colder
air from NW-SE during Tuesday night. Despite variable cloud
cover, this should again yield overnight lows in the single
digits to lower teens.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 303 AM EST Sunday...Generally quiet conditions expected
Wednesday through Friday. High pressure is expected to build
sewd from Quebec into New York and New England Wed/Thu time
frame, with developing southerly return flow on Friday as the
center of the anticyclone drifts southeast of New England.
Temperatures will gradually moderate...starting with the upper
teens to lower 20s on Wednesday, to the mid-upr 20s
Thursday...and finally above freezing with highs in the 35-40F
range for Friday afternoon. Thereafter, we continue to monitor
NWP trends with expected closed srn stream wave across the srn
tier of the U.S., and potential interaction/phasing with a
northern stream shortwave trough on Friday and through the
weekend. The 00Z ECMWF has trended away from previous runs,
showing that the two features do not completely come into phase,
allowing most of the precipitation and rich moisture to remain
to our south on Saturday, with the modest northern stream wave
bringing scattered rain/snow showers. Meanwhile, the 00Z FV3 and
GFS still indicate a deep closed low approaching from the Ohio
Valley for Friday night into Saturday, with mixed wintry
precipitation changing to mainly rain for the daylight hours
Saturday, including the potential for briefly moderate to heavy
rainfall given significant moisture advection from the Gulf of
Mexico and swrn Atlantic. For now, official forecast continues
to lean toward the more consistent GFS soln, with 70-80% PoPs on
Saturday and high temperatures expected in the 40s. However,
phasing between the northern and southern streams is uncertain
per 00Z ECMWF. Some continued changes in the forecast are
plausible in these types of synoptic regimes where timing of
individual shortwaves in the Day 5-7 period are strongly
influencing the forecast.
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...Expect VFR/MVFR ceilings through the period
with a few breaks through 00z where scattered clouds may
develop. The flow will turn to the northwest and satellite
imagery shows extensive area of clouds will be moving back down
across the area with ceilings remaining in the VFR/MVFR category
for the remainder of the period. There may be some light snow
showers...but visibilities should remain in the VFR category.
Gusty south to southwest winds...gusts in the 18 to 28 knot
range...will continue through 00z before tapering off and
becoming northwest after 06z.
Monday Night: VFR. NO SIG WX.
Tuesday: Mainly VFR, with local MVFR possible. Slight chance
Tuesday Night: Mainly VFR, with areas MVFR possible. Slight
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Friday: VFR. Slight chance SHRA, Slight chance SHSN.