Area Forecast Discussion
Issued by NWS Burlington, VT-- Remove Highlighting --
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FXUS61 KBTV 251051
Area Forecast Discussion
National Weather Service Burlington VT
651 AM EDT Thu Aug 25 2016
Increasing moisture and a trough of low pressure will help to
increase clouds and precipitation chances today through Friday
morning. High pressure begins building into the region Friday
afternoon and will provide drier weather right through Sunday
morning. Above normal temperatures are expected today and Friday
with readings right around seasonal normals for the weekend.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 651 AM EDT Thursday...Minor tweaks to sky cover and
temperatures to match current conditions...otherwise going
forecast looks good. Southwest flow aloft will continue to bring
moisture into the region today. This combined with a weak trough
of low pressure moving in will be enough to produce some
precipitation...especially later this morning and afternoon.
Instability forecasts appear to be a bit overdone as dew points
not expected to reach the upper 60s. So its looking like some
instability develops due to surface heating and a slight increase
in dew points and this will be enough to include the potential for
a few thunderstorms. Deep layer shear not that impressive as well
and thus no expecting anything to get organized. High temperatures
today should be in the upper 70s to lower 80s.
Tonight: southwest flow aloft continues over the area and now we
should see some higher dew points with readings climbing into the
60s. Instability diminishes tonight and any forcing gradually
shifts east of the area. Best chances for precipitation appear to
be from the Champlain Valley eastward. Clouds and higher dew
points tonight suggest lows will generally be in the 60s to around
-- End Changed Discussion --
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
As of 253 AM EDT Thursday...Forecast challenge continues to be
areal coverage of potential precip on Friday morning across our
eastern forecast area. NAM/GFS are in good agreement with best 850
to 500mb moisture at 12z from the Champlain Valley eastward...while
ECMWF shows a moderate band of qpf from eastern Lake Ontario into
central VT around 12z. This seems to be related with some
convective feedback issues...therefore will trend toward chance
pops from Champlain Valley eastward through 15z...then taper to
<14% by afternoon. Soundings show deep dry layer and associated
subsidence between short wave energy building...as pw values fall
from 1.75 to 0.75 inches by 00z saturday. This drying will support
mostly sunny skies by afternoon with temperatures warming into the
80s...with only weak cold air advection behind boundary. By 12z
saturday a 1025mb surface high pressure is building into the North
Country with dry north winds continuing. A seasonably cool day
with low relative humidity values are expected on Saturday...with
temps mainly in the 70s. Winds will generally be from the
north/northwest at 5 to 15 mph.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 253 AM EDT Thursday...Overall large scale pattern supports
building ridge across the Mid Atlantic States with moderately
fast westerly flow aloft over the NE CONUS. Both ECMWF and GFS
show next short wave energy and ribbon of enhanced mid level
moisture approaching our western zones by 00z Monday...and quickly
spreading eastward overnight into Monday. Will continue with
previous forecaster idea and mention chance pops during this time
period. Instability looks minimal with surface based CAPE values
<500 J/kg and lis around -1c. Thinking best window for showers
will be between 21z Sunday into 06z Monday...based on 850 to 500
moisture and progged position of 5h vort associated with trof
lifting across southern Canada. Surface high pressure redevelops
across the region for Tuesday into Wednesday with dry conditions
anticipated. Surface analysis shows breezy southwest winds are
likely on Sunday ahead of boundary with gusts to 30 mph possible
Saint Lawrence and Champlain Valley. Progged 850mb temps warm to
16c by 18z Sunday...supporting upper 70s mountains to mid 80s
valleys. If clouds arrive sooner than anticipated temps will be 4
to 8 degrees cooler on Sunday...based on this have stuck very
close to superblend numbers. On Monday very weak low level cold
air advection develops behind front with progged 850mb temps
dropping back between 12c and 14c...supporting highs l/m 70s
mountains to upper 70s to lower 80s valleys. Warmer temperatures
build by the midweek with progged 850mb values around 18c by 12z
Thursday. This will support highs well into the 80s with lows
mainly in the 50s mountains to 60s valleys. Overall...rh values
will remain in the comfortable zone through midweek...before
increasing toward next weekend. Next chance of showers/storms
arrives late next week.
.AVIATION /12Z Thursday THROUGH Monday/...
Through 06Z Friday...Overall looking at VFR conditions through the
period. Expecting scattered showers and isolated thunderstorms to
move across the area mainly between 16z and 00z...but again
looking at VFR conditions with some MVFR ceilings and visibilities
in and near any of the showers or storms. Winds will be increasing
from the south and southwest this morning with gusts in the 15 to
25 knot range...especially this afternoon...before gusts taper off
NOTE: Rutland AWOS (RUT) is now operational.
Outlook 06Z Friday through Monday...
06Z Friday through 18Z Friday...VFR with scattered MVFR/brief IFR
in scattered showers/thunderstorms. Brief heavy downpours with
reduced visibility and turbulence in stronger convective cores.
18Z Friday through 00Z Monday...VFR/high pressure.
00Z Monday onward...VFR with scattered showers/MVFR possible.
As of 0730 PM EDT Wednesday...The AWOS (automated weather
observing system) at the Rutland-Southern Vermont Regional Airport
(KRUT) is now back in service and operational.