Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 220541
Area Forecast Discussion
National Weather Service Burlington VT
141 AM EDT Thu Sep 22 2016
A ridge of high pressure will remain over the north country
through most of Thursday. A cold front will move south from Canada
Thursday night and early Friday. This cold front will bring rain
showers to the north country Thursday night and Friday. A ridge of
high pressure will then build south from Canada on Saturday and
will remain over the north country through next Wednesday. Fall
like temperatures will be over the north country Saturday and
Sunday with high temperatures in the upper 50s to lower 60s.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 1248 AM EDT Thursday...Another night of wide ranging
temperatures so just some minor tweaks to the grids to reflect
this variability. Otherwise should see a few high clouds moving in
as the night wears on and a low potential for widespread fog.
On Thursday, a ridge of high pressure will be over the region
early Thursday. However, expecting increasing clouds during the
day on Thursday with highs mainly in the 70s, except for some
lower 80s in some valley locations during the day on Thursday. A
cold front will be approaching the international border late in
the day on Thursday. Have gone with slight chance pops for rain
showers in the Saint Lawrence valley in northern New York late
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
As of 400 PM EDT Wednesday...A sharp cold front with a band of
rain showers will drop from north to south across our region on
Thursday Night into Friday. Both GFS/NAM show ribbon of enhanced
850 to 500mb moisture...along with best 850 to 700mb fgen fields
along the international border. Have mention likely to cat (70 to
90%) northern cwa to chc/likely (40% to 60%) southern/central
sections on Thursday Night into Friday. Best forcing/moisture and
associated qpf fields are across our cwa between 03 UTC and 09 UTC
Friday. Thinking qpf will range around 0.25 to 0.50 northern
mountains to <0.10 southern sections. Breezy north/northwest winds
flow fropa on Friday morning with moderate low level cold air
advection. Progged 850mb temps start near 15c at 06z Friday...but
fall to 5c by 00z Saturday...with similar trends in the 925mb
temps. This presents a tricky min temp forecast on Friday morning
and high temps for Friday afternoon...given the advection and
timing of front. Will mention lows mainly in the 50s to near 60f
on Friday morning with clouds/precip and fropa timing...but highs
only warming into the 60s on Friday afternoon with brisk north
winds. Temps will probably fall throughout the morning
hours...before leveling off and rising some when more sun during
the late afternoon on Friday. Northerly flow should advect drier
air in aloft...with some lingering upslope clouds likely across
the mountains for much of Friday.
For Friday Night...expect clearing skies with building high pres
from the north. Both NAM/GFS show deep dry layer directly
overhead..with still some gradient flow between building high pres
and departing low pres. Thinking the clearing skies and progged
850mb temps dropping to near 0c supports our coldest night of the
early fall season...with lows ranging from the m/u 20s mtns to upper
40s near lake champlain. Given expected thermal and wind profiles
areas of frost look likely on Saturday Morning away from Lake
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 400 PM EDT Wednesday...Large scale pattern amplification is
advertised by 12z guidance...supporting a mostly dry forecast
with slightly below normal temps. GFS/ECMWF indicate an omega type
pattern with trof across Eastern Canada...ridge East Coast...and
another deep trof over the central Conus. Models are
having difficulties on when pattern will break and associated
timing of trof across the central plains will impact our region by
late next week. Otherwise...deep dry layer will result in large
diurnal swings in temps from cool overnight lows to mild daytime
Saturday...a cool day anticipated with clouds developing over the
mountains associated with upslope flow and low level cold air
advection. Soundings are very dry...but still cannot rule out a
sprinkle or light shower over the dacks/northern greens on Sat
Aftn...associated with 5h vort in the northwest flow aloft. Progged
850mb temps near 0c...with brisk northwest winds support highs only
in the 40s mountains to upper 50s warmer valleys. Clear and chilly
with areas of frost expected on Saturday Night/Sunday morning with
lows ranging from the mid/upper 20s SLK/Northeast Kingdom to low/mid
30s central VT/SLV to mid 40s near Lake Champlain.
Sunday...Another 5h vort in the flow aloft impacts northern VT
around 18z...but once again deep layer moisture is limited. Have
mention schc to very low chc pops to cover the potential for a light
shower or sprinkle but qpf will be very light < 0.10". Little change
in thermal profiles expected with highs mainly in the upper 40s to
near 60f depending upon location and elevation.
Early next week...mid/upper level ridge builds with warming low
level temperature profiles. This supports a dry forecast with near
normal temps. Expecting highs mainly in the mid 50s to upper 60s and
lows mainly in the 30s and 40s. Next chance for rain is late next
.AVIATION /06Z Thursday THROUGH Monday/...
-- Changed Discussion --Through 06Z Friday...VFR conditions are expected through the
period. Expecting only mid and high level clouds to move into the
region through 00z before clouds slowly begin to lower...but still
remain above 5000 feet. Dry conditions are expected for much of
the period...but as a cold front begins to move down from
Canada...the threat for showers will increase at KMSS after 04z.
The bulk of precipitation will not move into the entire area until
after 06z. Light winds this morning will increase from the south
and southwest by midday and persist through the period...but
speeds will generally be under 15 knots.
Outlook 06Z Friday through Monday...
06z Fri to 00z Sat: MVFR with scattered showers associated with a
00z Sat through 00z Tue: Mainly VFR as a ridge of high pressure
builds into the region.
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