FXUS61 KBTV 190752
Area Forecast Discussion
National Weather Service Burlington VT
352 AM EDT Mon Aug 19 2019
A broken line of showers and embedded thunderstorms will move
across the North Country this morning with brief heavy rainfall
and localized wind gusts to 30 mph. Additional afternoon showers
and storms are possible, mainly over eastern Vermont.
Temperatures will warm well into the 80s with a few readings
approaching 90 degrees in the Champlain and lower Connecticut
Valley. A dry and warm day is expected on Tuesday, followed by
more chances for showers and storms on Wednesday into Thursday.
.NEAR TERM /THROUGH TUESDAY/...
As of 325 AM EDT Monday...Forecast challenge continues to be
convective chances and associated pops today. Water vapor shows
modest height falls across the eastern Great Lakes associated
with channeled 700 to 500mb vort, along with a ribbon of
enhanced mid level moisture. Regional mosaic radar indicates a
broken line of showers with embedded storms approaching the SLV
early this morning. Based on high res convective allowing
models, expect precip acrs dacks btwn 09z-11z, cpv 11z-13z,
central VT 13z-14z, and thru NEK/eastern VT by 16z. Laps shows
limited instability ahead of this line with CAPE values
generally <500 j/kg, but some elevated instability is present.
Thinking brief heavy rainfall and localized gust to 30 mph
possible within the heavier convective elements this morning.
Meanwhile, water vapor shows large area of subsidence/dry air
aloft building behind short wave energy, which should result in
clearing skies this aftn. This clearing will help warm temps
quickly into the 80s with a few locations near 90f in the
CPV/lower CT River Valley. The sfc heating will help create sfc
based cape values in the 1000 to 2000 j/kg across CPV and
portions of VT, while 0 to 6km shear is in the 35 to 40 knot
range. These parameters would support some organized convection,
however developing warm nose/cap around 800mb, along with deep
dry layer btwn 850 and 300mb with limited upper level forcing
will result in minimal activity this aftn/evening. Have mention
only schc/low chc (15% to 30%) pops from eastern Dacks into Vt
thru this aftn/evening.
Tonight into Tuesday...relatively quiet period of weather
anticipated with building heights and modest cap in place,
combined with dry air will limit threat for showers/storms.
Cannot completely rule out a stray shower/storm on Tues aftn
during peak heating/instability across the eastern Dacks or
higher trrn of Green Mtns. The best convergence will be
associated with lee side trof/lake breeze boundary interaction
on the west side of the CPV. 925mb to 850m thermal profiles are
slightly cooler on Tues with highs generally in the upper 70s
to mid 80s anticipated, with some drier dwpts/lower humidity
values as better mixing occurs during the aftn hours. Some areas
of patchy fog is likely tonight, with clearing skies and light
winds, especially as cross over values are reached in many
locations. Lows a little cooler than recent nights with readings
from the mid 40s slk to lower 60s CPV.
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 351 AM EDT Monday...Still a tricky forecast for Wednesday with
variability among the models regarding precipitation/convection
and timing of the system. This is largely due in part to how
each model is handling upstream convection over Ohio River
Valley Tuesday night into Wednesday. Current run of NAM now
depicts convection lifting northward across the area with GFS
maintaining the more southern track of convection and boundary
and ECMWF somewhere in between (however the actual frontal
passage on Euro is now not until 18z Thursday)...have maintained
relative consistency with previous forecasts until there is
better consensus. Regardless of forcing mechanism, I do think
there will be precipitation around during the daytime on
Wednesday. Additionally, with such differences among the models
it is difficult to determine the potential for severe weather.
Given trends in moisture profiles and available CAPE/shear
thinking can`t rule out some stronger storms with primary threat
being wet microbursts.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 351 AM EDT Monday...Lingering moisture and upper level
troughing will keep chances for precipitation around on Thursday,
especially across the northern tier. Better cold air advection
arrives Thursday night so temperatures will be near normal in the
mid to upper 70s. Friday will bring "fall-like" weather with breezy
NW winds and variably cloudy skies. GFS-MOS guidance is coldest
among suite with highs in the mid to upper 60s valleys and 40s
mountains, however have ran with a blend of EURO/MOS for highs in
the upper 60s to low 70s across the area. Certainly feels like we`re
beginning to make the turn. After this, quiet weather is expected
for the remainder of the long term with Canadian high pressure in
control of the weather. Temperatures warm each day of the weekend
with near seasonable highs in the mid to upper 70s. Overnight lows
will be once again pleasant in the upper 40s to low/mid 50s.
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...Changeable conditions anticipated this
morning with a window of fog/br and associated ifr possible at
slk/mpv. In addition, line of showers/embedded storms will
impact our western taf sites btwn 09z-12z this morning with a
period of mvfr vis/cigs. IFR in fog/br most likely at slk
through 09z, however expecting conditions to improve as
clouds/precip and mixing develops with approaching line of
showers. Meanwhile, at mpv thinking fog/br develops btwn 06-07z
associated with window of clearing skies and light winds, before
lifting around sunrise. Elsewhere, mainly vfr conditions prevail
with approaching showers toward sunrise. Expect south/southwest
winds to increase behind showers at 10 to 15 knots with
localized gusts up to 20 knots at slk/mss and btv.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. Chance SHRA, Chance TSRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Likely
SHRA, Slight chance TSRA.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.
Thursday Night: VFR. Slight chance SHRA.
Friday: Mainly VFR, with local MVFR possible. Slight chance SHRA.