Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRNK 250140
Area Forecast Discussion
National Weather Service Blacksburg VA
940 PM EDT Sun Jul 24 2016
Strong high pressure aloft will continue to bring increasing
heat and humidity through Monday. A series of weak surface cold
fronts approaching from the northwest should gradually bring an
increasing threat for showers and storms by the middle of next
.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --As of 931 PM EDT Sunday...
Slow moving showers and storms around Bland county into Mercer
County should weaken by 11pm. The 18z local WRF showed this
activity at 01z. As we head into the overnight we will see patchy
fog under some high clouds, though most of these should be thin. Lows,
mid/upper 60s west to 70-75 east.
Previous valid discussion...
Upper level ridge over the region is expected to sink south over
the next couple of days. Heights over the area will be at its
highest through Monday. Temperatures across the mountains will
peak into the upper 80s to lower 90s with ridges being a tad
cooler. East of the Blue Ridge and into the piedmont, temperatures
will warm into the mid to upper 90s. Dew points across the south-
central piedmont of Virginia will likely remain in the 70s,
producing heat indices values near 105F. A heat advisory has been
issued for this area for Monday.
Otherwise expecting mainly sunny skies with convection quite
limited given little support aloft and warm mid level temps. Still
appears some weak low level convergence across the western ridges
could combine with heating/instability to pop isolated to
scattered slow moving storms across the mountain by mid
-- End Changed Discussion --
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 310 PM EDT Sunday...
Slight drop in 500 mb heights is forecast by the models on
Wednesday. No significant change in air mass this time frame either.
850MB temperatures do not go any lower than +18 through Wednesday
night. There will be some increased low level convergence along the
tail of a weak front that crosses from the northwest into the
forecast area on Tuesday. While the front may stall to the north
there will still be some troffing on the lee side of the
Appalachians on Tuesday and across North Carolina on Wednesday.
Enough daytime mixing on Tuesday and Wednesday to lower surface dew
points in the afternoon. This will keep heat index values in
the piedmont just below heat advisory criteria.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 315 PM EDT Sunday...
Amount of troffing in the eastern United States for the end of
the week is questionable. GFS was the more amplified while the
ECMWF was slightly flatter. Friday looks to be the next day with
any potential for decent upper support. Will have the higher
probability of precipitation on Friday and Saturday afternoon and
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
As of 718 PM EDT Sunday...
Anticipate a repeat or close to last night. VFR outside any fog at
LWB/BCB late, may see some MVFR fog at DAN. Small area of showers
northwest of LWB at this writing should weaken and stay north of
LWB through 01z.
Monday will see ridge overhead again, but some better convergence
along the southern Blue Ridge into the Southeast WV mountains may
allow for more shower or storm coverage. Nonetheless will be
widely scattered. Confidence high enough to at least put VCTS at
BLF/BCB for now after 19z Monday.
Extended aviation discussion...
Ridge will finally weaken through mid week as an initial cold
front sinks toward the area from the northwest. This should bring
about an increase in daily convective coverage Tuesday into
Friday with periodic MVFR/IFR possible. Late night and early
morning fog will likely occur at the usual valley locations, and
those chances increase across the entire region if any rain occurs
during the afternoon or evening at any site.
Record high broken at Blacksburg today as we reached 93. Previous
record was 92 in 1991.
Record high temperatures for Monday (7/25)
Roanoke.....100 in 1934
Lynchburg...102 in 1934
Danville....102 in 2010
Blacksburg...92 in 1987
Bluefield....90 in 1987
VA...Heat Advisory from noon to 8 PM EDT Monday for VAZ046-047-058-