FXUS61 KBTV 270556
Area Forecast Discussion
National Weather Service Burlington VT
156 AM EDT Tue Jun 27 2017
Showers will come to an end early this morning but become rather
widespread during the late morning and afternoon hours across
the entire area. In addition...the potential for thunderstorms
will exist and gusty winds and small hail will be possible with
any of the storms. The showers and storms end tonight and much
of the area will be dry on Wednesday with just the possibility
of some showers up along the international border. Below normal
temperatures will continue through midweek...but a warmer and
wetter pattern sets up for the rest of the week and into the
.NEAR TERM /THROUGH TONIGHT/...
As of 156 AM EDT Tuesday...Line of showers continues to move
northeast across Vermont early this morning and should be out of
the area by 400 AM. Noticeable clearing behind this line has
already allowed for some fog to develop across parts of northern
New York and this will be the case across Vermont over the next
The dry weather will not last long as well defined shortwave
trough moving out of the eastern Great Lakes early this morning
is enhancing convection at the moment. This feature moves across
our area during the late morning and afternoon hours and
increase dynamic support across the region for greater areal
coverage of showers and isolated storms across our area. Going
forecast of convection ramping up into the likely category looks
real good. Colder core aloft associated with the shortwave
trough will steepen lapse rates over the area and despite cooler
temperatures today...sufficient instability will develop with
CAPE values in the 200-500 J/kg range. Low wet bulb zero values
and layer of drier air in the sub-cloud region both point to
gusty winds and small hail with any of the stronger convection.
Going forecast already has this in and will continue to
Shortwave then exits east through the evening hours on Tuesday with
convective coverage lessening over time and leaving a mainly dry
overnight period. Again, a few early evening storms may spit
out some small hail east early. Low temperatures perhaps a
degree or two cooler than tonight, generally upper 40s to mid
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 247 PM EDT Monday...Wednesday looks to be a relative
minimum in the convective activity for the week. Northwest flow
aloft in the wake of the shortwave should dry things out despite
a fair amount of cold air aloft. There will be some instability
developing in the afternoon but areal coverage should remain
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 247 PM EDT Monday...Thursday will begin a stretch of
active weather through the end of the week. A wave along a
frontal boundary will travel north of the border Thursday
through thursday night with a boundary stretched out east to
west. Showers and thunderstorms will develop to the west of the
area in the lower great lakes and southern Ontario and move east
along the boundary. Instability progged to be meager Thursday
and thursday night so overall thunder chances area fairly low.
Instability increases Friday so increased thunder chances Friday
and Friday night.
Southwesterly flow will continue to transport more moisture rich
air into the region Friday and Saturday. Available instability
progged to increase with the moisture plume moving into the
area, but deep layer shear is meager at this point. PWAT values
by Saturday way back up into the 1.50-2.00" range and heavy
rainfall is definitely a concern. The rainfall of the last week,
combined with whatever falls Thursday could set the stage for a
flash flood event Saturday. Amount and location of Thursday`s
rainfall will set the antecedent conditions for any potential
flooding Saturday. Still quite far out in the forecast, but
definitely bears watching.
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Showers will be exiting Vermont by about
09z this morning and clear skies over northern New York should
move into Vermont as well. Moisture from the evening and early
morning rainfall combined with the clear skies and light winds
will produce a period of IFR to VLIFR conditions at a number of
locations due to the development of fogs and low clouds. These
lower conditions will last until about 12z before low level flow
increases and promotes mixing. An upper level trough of low
pressure moves into the region later this morning and afternoon
and widespread showers are expected between 16z and 22z.
Conditions will mainly be VFR...but may lower into the MVFR
category during this period due to the showers. The potential
will exist for thunderstorms and any of the storms will have the
potential to produce gusty winds and small hail. The
precipitation comes to an end around 00z and VFR conditions are
expected for the remainder of the period.
Tuesday Night: VFR.
Wednesday: VFR. Slight Chance SHRA.
Wednesday Night: VFR. Slight Chance SHRA.
Thursday: VFR/MVFR. Likely SHRA.
Thursday Night: VFR/MVFR. Likely SHRA...Slight Chance TSRA.
Friday: VFR. Chance SHRA...Chance TSRA.
Friday Night: VFR. Chance SHRA...Chance TSRA.
Saturday: VFR/MVFR. Likely SHRA...Likely TSRA.