Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/29/22
Area Forecast Discussion
National Weather Service Burlington VT
938 PM EST Mon Nov 28 2022
As high pressure moves overhead, dry and seasonably cold
conditions are expected through tomorrow as clouds gradually
erode. South winds will develop early Wednesday and become
locally strong in the northern Adirondacks and northernmost Lake
Champlain area ahead of a sharp cold front. The front will help
focus widespread rain showers during the day, and its passage
Wednesday night will produce breezy west winds and cause
temperatures to tumble back to normal by Thursday.
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 936 PM EST Monday...A quick glance at area webcams has
shown that the scattered flurries from earlier in the evening
have largely ended. Latest HRRR and RAP soundings show the DGZ
has unsaturated with just low level clouds residing across the
region. These clouds should be stubborn over the next few hours
but should see a steady decrease in area coverage starting
Previous Discussion...A typical post-frontal regime with mainly
cloudy skies with breaks due to downsloping off the higher
peaks is in place this evening. As a ridge of surface high
pressure to our west moves overhead tonight, northwest flow will
relax. Winds at the top of the mixed layer, roughly 850
millibars, are expected to drop below 10 MPH, so where clouds
erode temperatures should fall off nicely. Have kept hourly
temperatures relatively elevated where clouds are more likely to
linger overnight in portions of the Adirondacks and vicinity of
the Green Mountains, while many lower elevation sites,
especially east of the higher terrain, will be able to see
temperatures fall back sharply with good radiational cooling
conditions. All in all, a fairly seasonable air mass will be
over our region so temperatures tonight are looking to drop into
the 15 to 25 range in most spots and highs mid 30s to low 40s.
By early Wednesday morning, high pressure moves to our east and
our region sees substantial return flow sandwiched between this
high and strong low pressure lifting into the northern Great
Lakes. As a result, winds at high elevations and over Lake
Champlain will ramp up. Channeled flow in our wide valleys will
help temperatures rise overnight through the 30s given mixing
of the increasingly warm air aloft. Accordingly, a strong
surface inversion should be in place given the warming aloft
such that sheltered lower elevation sites, especially in eastern
Vermont, will be much colder than elsewhere with lows again
dropping back into the 20s. Any precipitation should hold off
until the daytime hours but clouds will be on the increase
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 315 PM EST Monday...Cold front then crosses the region
Wednesday into Wednesday night with another round of steadier
rainfall expected on the order of 0.5 to 1 inch. A brief period
of wet snow may be possible across the Adirondacks right at
precipitation onset during mid to late morning, but impacts
should be minimal with afternoon high temperatures expected to
top out from the mid 40s to lower 50s. Gusty southerly flow will
also be prevalent ahead of and immediately along the boundary
in the late morning to afternoon time frame with latest model-
blended 925 hPa flow supporting gusts from 20 to 30 mph area
wide. Locally higher gusts from 30 to 45 mph will be possible in
a narrow 6 hour time frame from late morning into early
afternoon, mainly in the Champlain Valley due to channeling and
along the northern slopes of the Adirondacks for modest
downsloping effects. Some isolated power outages will be
possible in these areas, but again, widespread impacts are not
Frontal boundary then clears quickly east Wednesday evening/night
with precipitation waning in coverage and becoming more scattered in
nature as flow remains modestly gusty and backs to westerly. Some
minor snow accumulations will be possible across the higher terrain
on the order of a dusting to perhaps two inches, especially in the
Adirondacks where some lake effect response off Lake Ontario is
expected. Other than a few flurries or spits of light snow/rain
showers, no accumulations are expected in the broad valleys. Lows 25
to 32, give or take a degree or two.
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 315 PM EST Monday...Thereafter, trending mainly quiet
Thursday night into Friday night as high pressure bridges across
the region with fair and seasonably cool weather. Our next
frontal system then arrives on Saturday into Saturday evening.
Once again, the main system core will pass north of our area
with gusty southerly flow becoming established and mainly a rain
event expected as highs top out in the 40s. Afterword, a
general tapering to scattered rain/snow shower activity should
occur by Saturday night in the post-frontal westerly flow
Then trending cooler and quieter once again by next Sunday
under high pressure with highs mainly in the 30s.
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...Lingering low level moisture is
continuing to promote widespread MVFR conditions across the
North Country with most terminals experiencing CIGs in the
015-030ft AGL range. MSS/RUT remain VFR, 033ft and 035ft
respectively, but could lower to MVFR by 06Z before drier air
can scour out moisture. The overall trend in the forecast has
been to linger cloud cover longer overnight, so it could be
08-14Z before all terminals return to VFR. Winds are generally
out of the northwest with widening temperature/dewpoint spread,
so eventually moisture will erode. Light winds and much clearer
skies are expected 12-00Z.
Tuesday Night: VFR. Windy with gusts to 30 kt. NO SIG WX.
Wednesday: Mainly MVFR, with areas VFR possible. Windy with gusts
to 35 kt. Definite RA.
Wednesday Night: Mainly VFR, with areas MVFR possible. Chance
SHRA, Chance SHSN.
Thursday: Mainly VFR, with local MVFR possible. Chance SHSN,
Slight chance SHRA.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. Windy with gusts to 30 kt. Chance SHRA, Slight
Saturday: Mainly VFR, with local MVFR possible. Strong winds with
gusts to 40 kt. Chance SHRA.
The KCXX radar will be down for approximately 2 weeks (through
approximately December 12) for a scheduled pedestal replacement
on site. This a critical repair to ensure the operational
longevity of the equipment.