486
FXUS61 KBTV 120711
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
311 AM EDT Thu Mar 12 2026
.WHAT HAS CHANGED...
As of 237 AM EDT Thursday...
Confidence has increased in possible advisory snow amounts for a
clipper system Friday into Saturday, as well as for an impactful
storm system for early next week.
&&
.KEY MESSAGES...
As of 237 AM EDT Thursday...
1. The potential for localized and minor ice jam related
flooding continues through Today, along with minor open water
flooding forecasted for the Ausable River and Otter Creek.
2. A strong cold front will sweep through the area this
morning, bringing gusty winds and much colder air.
3. A clipper system will bring a few inches of snow and some
gusty winds Friday into early Saturday.
4. High amplitude pattern will set the stage for an event with
several weather hazards early next week.
&&
.DISCUSSION...
As of 237 AM EDT Thursday...
KEY MESSAGE 1: The latest forecast from the Northeast River Forecast
Center still indicates the Ausable River and Otter Creek are
expected to reach minor flood stage today with Action Stage possible
on the Lamoille, Winooski, Mad, Barton, Oswegatchie, St. Regis, and
Missisquoi Rivers. Open water flooding will be the main concern on
the Ausable River and Otter Creek from snow melt, as most of the
river ice has cleaned out.
Additional rainfall this morning will be variable with values
ranging from 0.1" to 0.3" as a corridor of heavier showers ahead of
a cold front slides east. These rainfall amounts will cause
additional rises on rivers and streams, this combined with numerous
ice jams in place, could cause renewed localized ice jam flooding.
The greatest potential for additional ice jam flooding based on
current ice jam locations would be the St Regis River at Hogansburg
and Brasher Falls, Saranac and Great Chazy. Still think we have to
watch the Passumpsic River near Lyndonville closely with additional
snow melt and rainfall expected today; ice movement is already
present on the Sleepers River.
Temperatures will return to normal levels with reduced flooding
concerns through the weekend, but slow river falls will keep river
levels elevated through today and tomorrow.
KEY MESSAGE 2: A strong cold front is beginning to push into the
region this morning trailing a band of locally higher rain
showers. Shower activity is mainly scattered as the boundary
shifts east, and should exit the region just after sunrise this
morning. Column moisture content should dry our in the mid
levels reducing the chances for any post frontal snow showers.
River flooding, as discussed in Key Message 1, will be somewhat
impacted by the footprint of the highest rainfall amounts as the
specific basins have seen highly variable amounts of rain.
Temperatures will fall rapidly behind the rain this morning,
with some locations falling 20-30 degrees within a few hours,
namely the Champlain Valley. Temperatures will ultimately level
off in the upper 20s to low 30s by this afternoon, aided by
weak caa with gusty west to northwest winds this morning. These
morning gusty winds are associated with a low level jet of
45-55kts, with the overall expectation that as the low to mid
levels cool aloft, lapse rates will steepen as surface
temperatures lag in total cooling. These lapse rates will
support mixing with gusts mainly 30-40 MPH in Vermont and the
St. Lawrence Valley, with occasional 40-45 MPH gusts along the
northern fringe of the Adirondacks and northern St. Lawrence
Valley, north of US Route 11. Winds will peak around sunrise
this morning, remain breezy through today, and weaken by this
evening. Higher, prolonged gust potential looks to reduced as
the orientation of the winds at peak mixing is not supportive of
downsloping, in addition to the peak low level jet ahead of the
boundary.
KEY MESSAGE 3: A clipper type system will move through the
region from west to east Friday into Saturday morning. A few
inches of snow are expected across northern New York and
Vermont. A retreating high early Friday may lead to slightly
reduced amounts if dry air lingers, but a quick burst of snow is
increasingly likely Friday afternoon across the area. The
current timing of the snow onset could effect the Friday evening
commute.
The track of the system does not bode confidence in high
snowfall amounts. These clipper system typically do not yield
enough time for enhanced snow rates, nor carry the moisture
needed for higher snow totals. Furthermore, the track of this
system in the hi-res guidance depicts the surface low to move
over the St. Lawrence Valley and northern Vermont. This would
support shadowing across the Champlain Valley and eastern
Vermont, with the higher amounts in the higher terrain, mainly
the western facing slopes of the northern Adirondacks. The
current forecast shows generally 2-3 inches across the St.
Lawrence Valley, 3-6" across the western Adirondacks and a
dusting to an inch or two across Vermont. Probabilities of
exceeding 4" is mainly maximized over the Adirondacks at 60-70%.
If trends continue, a Winter Weather Advisory may be needed for
portions of St. Lawrence and Franklin Counties in New York.
Given marginal temperatures in the low to mid 30s, even with
some wet bulbing, some areas of rain are possible across the St.
Lawrence and Champlain Valleys as well as across southern
Vermont. It`s overall not a great setup for the Champlain
Valley or much of eastern Vermont to pickup much snow, but the
higher elevations of northern New York and northern Vermont will
get a nice coating of snow.
In addition to the snow potential, winds will also be a concern.
A deepening surface low riding behind a departing high will add
the influence of the isallobaric wind. Coupled with a 50-60kt
LLJ, winds may become gusty at times. Concerningly, the hi res
guidance is beginning to depict some downsloping potential
across northern New York with NAM3 soundings showing top of the
mixed layer winds around 50kts, and bottom of the mixed layer
winds to near 40kts. Ensembles show these features, but not as
high in magnitude, owing to a difference in surface low centers
among the hi res models which resides more north than the global
models. Have trended towards the NBM90th given the increased
model trends towards higher gusts, but trends will need to be
closely monitored, such that if realized, a wind advisory could
be needed.
KEY MESSAGE 4: The contrast of deep high pressure across the Atlantic
and intensifying low pressure across the Plains will result in deep
southerly flow. A 1035mb surface high will amble into the Canadian
Maritimes and send a warm front north on Sunday. The transition of
high pressure after a surge of cooler air is usually favorable for
mixed precipitation. The speed of incoming warm air and initial dry
air will likely make this a fast transition from snow to rain, and
then the front itself moves out quickly. Given the limited
precipitation and quickly increasing temperature Sunday night, there
may not be much impact. Behind the front, one will likely notice an
immediate surge of wind by Monday morning. Increasing surface
temperatures will allow better mixing as pressure gradients also
tighten. Temperatures will go from seasonable 40s on Sunday, to mid
50s and to lower 60s in Monday. A wave of moisture from the Atlantic
will lift north during the day. It could compete with terrain
shadowing, but a few showers will be possible throughout the day due
to lift from warm, moist advection. Some instability will also be
present. Winds will peak Monday afternoon, ahead of powerful frontal
boundary. Global guidance already depicts a linear type feature that
rushes east with a sharp thermal gradient. Behind the front,
temperatures will sink back into the 20s, and a few teens in
northern New York on Monday morning. Temperatures will gradually
moderate to seasonal norms behind the system as high pressure
becomes established.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...A frontal boundary is shifting east, and has
past KMSS, and is approaching KSLK/KPBG/KBTV. This will quickly push
east over the next couple hours. A brief dip to IFR ceilings or
visibility will be possible at KMSS, and then appears more likely
for KSLK and KEFK, 06z-08z and 08z-10z respectively. Until the front
exits east of Vermont around 12z, pockets of LLWS will remain across
several terminals. Behind the front, south to southwest winds around
5-10 knots will shift to west to northwest and increase to 9-16
knots sustained with gusts 18-28 knots, locally up to 30-33 knots
possible at KMSS. Ceilings may be slow to improve, but after
19z-22z, conditions will trend VFR as lingering moisture exits the
region. Based on shallow moisture in northwest flow, cannot discount
some flurries at areas like KSLK, but it seems unlikely.
Outlook...
Friday: VFR. Chance SN, Likely RA.
Friday Night: Mainly MVFR and IFR, with areas VFR possible.
Likely SN, Definite RA.
Saturday: Mainly VFR, with areas MVFR possible. Chance SN.
Saturday Night: VFR. NO SIG WX.
Sunday: Mainly VFR, with local MVFR possible. Chance SN, Chance
RA.
Sunday Night: MVFR. Windy with gusts to 30 kt. Likely RA, Chance
SN, Likely FZRA.
Monday: Mainly MVFR, with local IFR possible. Windy with gusts to
30 kt. Definite RA.
&&
.EQUIPMENT...
The Colchester Reef meteorological station is out of service.
This site is not serviced by the NWS and there isn`t an
estimated return to service at present. Please contact us if you
observe winds significantly deviating from the recreational
forecast.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Flood Watch until 2 PM EDT this afternoon for VTZ001>011-
016>021.
NY...Flood Watch until 2 PM EDT this afternoon for NYZ026>031-034-
035-087.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Haynes/Danzig/Boyd
AVIATION...Haynes
EQUIPMENT...NWS BTV
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