Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBTV 240740
Area Forecast Discussion
National Weather Service Burlington VT
340 AM EDT Mon Apr 24 2017
-- Changed Discussion --A dry cold front will pass southward across the North Country
early this morning, bringing a northerly wind shift and slightly
cooler temperatures. Skies will trend mostly sunny by late
morning or early afternoon. After a quiet night, low pressure
moving northward from the Carolinas will bring numerous showers
across our region on Tuesday, and across eastern and south-
central Vermont on Wednesday. Very warm temperatures are
expected on Thursday with high pressure in place aloft. A
surface cold front will bring the potential for more showers,
and potentially a thunderstorm, on Friday.
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.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --As of 328 AM EDT Monday...Relatively quiet weather today. A cold
front washing out near the intl border has brought a light nly
wind shift across far nrn NY and far nrn VT early this morning.
Will see a band of mainly mid-level clouds associated with this
boundary early this morning, but weak frontal convergence and
dry low-level air mass should preclude any frontal precipitation.
Will see increasing sun late morning/afternoon, but north winds
and low-level CAA will keep temperatures cooler than Sunday.
Looking for afternoon highs in the mid-upr 50s across nrn
sections, and low-mid 60s across the valleys of s-central VT as
cold front dissipates while tracking south. Continued quiet
tonight. Skies start mostly clear, but will see increasing cloud
cover from south- north associated with slow-moving closed low
over the Carolinas. This system will eventually spread light
showers nwd across our region during the daylight hrs Tuesday.
Marine modified low- level air will advect into ern VT, so will
see chilly temps on Tuesday with a low overcast; highs generally
upr 40s to lower 50s east of the Green Mtns. Looking for mainly
mid-upr 50s elsewhere...perhaps near 60F for highs Tuesday in
the St. Lawrence Valley. Total rainfall amts on Tuesday
generally expected 0.10-0.20", highest across s-central/ern VT.
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.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 313 PM EDT Sunday...Cool and damp conditions
expected...along with some breezy winds along the western slopes
from Danby to Rutland to East Middlebury to Underhill. Still
anticipating several waves of light rain to move from south to north
across our fa with 1st round btwn 15z and 21z Tuesday and 2nd wave
impacting our eastern/central cwa on btwn 09z and 15z Weds. Leading
5h vort and initial 850 to 500mb moisture quickly expands across our
region on Tuesday...while developing south/southeast low level winds
increase at 30 to 40 knots. The best winds associated with low level
925mb to 850mb se jet stay to our east...but still thinking a few
gusts to 30 knots possible along the western slopes on Tuesday. The
jet orientation will impact qpf fields with slightly higher amounts
on se upslope regions and less across the eastern cpv/western
slopes. General qpf will range between 0.05 and 0.25 for 1st round.
Next round of precip is associated with tightly compacted closed
mid/upper level cyclonic circulation and weak 1005mb low pres moving
along the eastern seaboard. Latest guidance continues to show a
sharp west to east precip gradient across our cwa...with minimal qpf
west and up to another 0.50 or so eastern/southeast sections on
Weds. Based on low level jet orientation/placement and pws near 1.0"
this looks reasonable. Have mention likely to cat pops east and
tapered to chc west on Weds with a sharp gradient in qpf fields.
Temps will also be depend upon clouds/precip with highs tues only in
the m/u 40s se section to mid/upper 50s nw areas...and near 70f SLV
to upper 50s CT River Valley on Weds. Lows hold mainly in the 40s on
Tuesday night with clouds/precip.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 313 PM EDT Sunday...Much above normal temps expected on
Thursday ahead of approaching cold front...with a band of
showers and embedded thunderstorms anticipated Thursday
aftn/night...before cooler air arrives by next week. Mid/upper
level ridge builds ahead of developing s/w energy over the great
lakes on Thurs...placing our CWA in the warm sector. The slower
fropa arrival allows for 925mb temps to warm between 20-
22c...with 850mb temps near 15c on breezy south winds. Have gone
3 to 5 degrees above superblend with highs mainly m/u 70s
mountain valleys to lower 80s warmer valleys away from Lake
Champlain. GFS continues to show an axis of instability ahead of
short wave energy and cold front with CAPE values btwn 800-1200
j/kg. Still some uncertainty with timing of fropa and
associated impacts. Cooler air eventually arrives late Friday
into Saturday...with a sharp boundary draped somewhere across
the ne conus/mid Atlantic states next weekend. This will produce
a sharp divide in warm/unstable air to our south and
cooler/drier air to our north...with unsettled wx located near
the boundary. Plenty of uncertainty on exact placement of
boundary and potential impacts at days 6 and 7...so kept mention
of chc pops with temps very close to superblend values...mainly
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...A dry cold front will bring a northerly
wind shift during the pre-dawn hours, along with a period of VFR
ceilings through 12-14Z or so. May see a brief period of MVFR
ceilings around SLK/PBG around daybreak, but overall impact
from this front will be rather limited. Skies will return mostly
clear later this morning and through the remainder of the TAF
period with sfc high pressure across srn Quebec in control of
our weather. No restrictions to vsby are expected through the
period. Winds generally N-NE at 5-10kts. Will see localized sely
winds at KRUT after 01Z Tuesday associated with local
Tuesday: VFR. Breezy. Chance SHRA.
Tuesday Night: VFR. Breezy. Chance SHRA.
Wednesday: VFR. Chance SHRA.
Wednesday Night: VFR. Slight Chance SHRA.
Thursday: VFR. Slight Chance SHRA...TSRA.
Thursday Night: VFR. Chance SHRA...TSRA.
Friday: VFR. Slight Chance SHRA.