Scientific Forecaster Discussion
fxus61 krnk 261923
Area forecast discussion
National Weather Service Blacksburg Virginia
323 PM EDT Wed Jun 26 2019
high pressure will cover our area through tomorrow bringing
mostly dry weather. Scattered showers and thunderstorms will
pepper the area Friday and Saturday. The better chance for
showers and thunderstorms will be associated with a cold front
that arrives later in the weekend.
Near term /through Thursday/...
as of 230 PM EDT Wednesday...
Similar weather pattern last night as high pressure remains
over the region. We will once again see fog forming in river
valleys during the early morning hours, burning off by 800 am.
Mid level ridging strengthens over the region on Thursday. This
ridging will produce temperatures a few degrees warmer than
today with highs in the mid to upper 80s across the mountains to
lower 90s east of the Blue Ridge. A modest cap will also
accompany the 850 mb ridge deterring widespread showers and
thunderstorms from forming during the day. However, we can not
rule out a stray short-lived shower along the Blue Ridge late in
Short term /Thursday night through Saturday night/...
as of 230 PM EDT Wednesday...
High pressure weakens on Friday giving the area a chance for
afternoon and evening showers and thunderstorms. Majority of the
storms will develop from orographical lift and diurnal heating
over the mountain during the afternoon, then fade shortly after
sunset. Some capping exist, but a few pulse storms could become
strong late in the afternoon and evening. Friday's high
temperatures will range in the mid to upper 80s across the
mountains to lower 90s east of the Blue Ridge.
Heights begin to fall on Saturday as a back-door cold front
approaches the region from the north. With an increase in heat
and humidity over the region along with a Lee trough, more
showers and thunderstorms are expected Friday afternoon and
evening. Storms may begin a few hours earlier than Thursday and
last deeper into the night. With lower heights and no capping, a
few storms will be become strong to severe producing small hail
and damaging winds gusts. High temperatures will once again
range in the mid to upper 80s across the mountains to lower 90s
east of the Blue Ridge.
Long term /Sunday through Wednesday/...
as of 245 PM EDT Wednesday...
The system that will bring a back door cold front into the area
this weekend will gradually move off the New England coast on
Sunday. Behind the front, cooler drier air works into the region
from the north. Despite the cool down, temperatures will only
lower to near normal levels for Sunday and Monday.
The combination of the low off the New England coast and upper
level ridge over the Gulf will set a path for upper Midwest
storms to track over the Ohio Valley and into our area early
next week. Taking a peak at next Wednesday (4th of july), one
such storm is expected to track across the area providing its
own firework light show.
Aviation /19z Wednesday through Monday/...
as of 115 PM EDT Wednesday...
The combination of a weak surface ridge and zonal flow aloft
will allow for VFR continues to persist today and into this
evening, with scattered cumulus clouds in the mountains and a
canopy of high cirrus clouds overspreading the area later today.
Winds under 15 knots are expected.
Similar to early this morning, River Valley fog will again
develop late tonight/early Thursday morning, primarily along the
new and Greenbrier rivers and impacting klwb with IFR vsbys due
to fog. These conditions will rapidly improve with VFR
conditions forecast for the entire region by 13z (9 am edt).
Extended aviation discussion...
High pressure is expected to take up residency over the region
into Friday. For the most part, VFR conditions are expected
outside of late night/early morning fog. Also, as we approach
the weekend showers and storms will be on the increase, and
these too may bring some temporary reductions to visibility and
Late Friday into Saturday, the chances of sub-VFR conditions
increase especially across the mountains with heating of low
level moisture aided by orographics. The arrival of a backdoor
cold front late in the weekend should allow for an increase in
coverage of showers and storms by Sunday afternoon.