195
FXUS61 KRNK 102052
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
452 PM EDT Wed Jul 10 2024

.SYNOPSIS...
A front moves to the Piedmont this evening, reaching the coast
Thursday morning, before buckling back west late Thursday. Low
pressure tracking along the boundary Friday through Sunday will
result in typical summer temperatures and daily chances of
precipitation.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 444 PM EDT Wednesday...

Key messages:

    - Severe Thunderstorm Watch Central VA Piedmont

    - Heat Advisory Piedmont Til 8pm Today

  - Lower humidity in the mountains

Severe thunderstorm watch for the Lynchburg to Buckingham area
in effect til this evening. Have already trimmed Bedford County
out of the watch, as the modest instability has shifted east
along a line from Staunton to Lynchburg. So far, convection has
not been that robust, but SBCAPEs of 2500-3500 exist ahead of
the front, but CAP is holding stronger just to the south. Made
adjustments to pops based on radar trends. Cannot rule out a few
sprinkles or showers over the mountains as well.

Previous discussion...

12z RNK sounding showing a SBCAPE of 4000+, but as the day
progresses forecast soundings and trends have warming aloft
leading to a cap for a small window this afternoon. Best low
level convergence and instability will be situated along/east of
a Staunton to Danville line. With PWATs staying elevated around
2.0" expect torrential downpours with thunderstorms, and
potential microbursts with the wet loading aloft, but main
threat of severe stays further north with better dynamics.

Trends in the models have main chance of showers/storms east of
the Blue Ridge this afternoon and north of the VA/NC border,
with little or none elsewhere.

Showers/storms fade/exit this evening with clearing skies and
lighter winds overnight. Dewpoints sink into the 50s in
mountains to lower 60s in the piedmont, so a welcome relief for
most.

Appears deeper moisture stays along/east of the front into the
VA/NC piedmont Thursday and high-res guidance keeps out rain in
our area, so lowered pops to little to no chance Thursday.

Humidity Thursday will also be tolerable with highs close to
normal, in the lower to mid 80s west to lower 90s east.

Forecast confidence is high on temperatures and humidity, an
average on storm coverage this afternoon.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 115 PM EDT Wednesday...

Key Messages:

1) Showers and storms Friday, then mainly east of the Blue
Ridge Saturday.

2) Cooler temperatures.

Expect increasing cloud cover in easterly flow Thursday night. By
Friday, low pressure off the Carolina coast will work inland,
bringing rain and thunderstorms in from the east. The higher QPF
values look to be over eastern/coastal VA, with lesser amounts
(quarter inch to a half inch) over our VA and NC Piedmont, generally
east of a Danville to Lynchburg line. Farther west, we will see
partly to mostly cloudy skies and a lower chance for showers/storms/
measurable QPF.

Instability looks poor, and SPC only has us in general thunder.
The bigger threat will be heavy rain leading to localized flooding,
which WPC has outlined in their latest ERO. Temperatures Friday will
be in the low to mid 80s which will be a nice break from the current
heat.

The low will work up the NE coastline Friday night into Saturday as
a short wave in the vicinity of the Great Lakes moves east. Saturday
will be a bit warmer with partly sunny skies and highs in the 80s
for the mountains, and the low to mid 90s for the Piedmont. There
will still be scattered afternoon and evening convection, mainly
east of the Blue Ridge.

Confidence in the near term is moderate.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 200 PM EDT Wednesday...

Key Messages:

1) Daily shower and thunderstorm chances, though drier days
look like Sunday and Monday.

2) Temperatures increase again, especially Monday through next
Wednesday, but humidity will be less of an issue.

Weak troughing aloft remains in place over the interior Mid
Atlantic, with a baroclinic zone stalled along the Atlantic coast.
This will bring periodic showers and thunderstorms, especially for
the Piedmont and along the southern/central Appalachians in the
afternoons and evenings. This will be mainly due to differential
heating and/or convergence and diurnal instability, without a lot of
synoptic support. In other words, summer convection. Sunday and
Monday look like the best bet for drier weather. The next chance for
widespread convection may come next Wednesday into Thursday as a
larger trough aloft approaches the OH Valley. This is supported by
NAEFS/GEFS outlooks, which underline the very normal weather
expected.

Sunday through next Wednesday look hot, with heat indices creeping
up around 100 or above Monday through Wednesday, which is supported
by the ECMWF Extreme Forecast Index and Shift of Tails Max and Min
T. The higher heat indices will mainly be because of incoming solar
radiation, west winds, and increasing heights contributing to higher
temperatures...and less like today`s heat advisory, in which dew
points were a bigger influence.

Confidence in the long term is moderate.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
As of 155 PM EDT Wednesday...

Thunderstorms will be widely scattered but close enough to
ROA/LYH/DAN to have VCTS in this afternoon, though not for long
at ROA. Southwest winds will turn west behind a front with gusts
to 20kts.

Mainly VFR through Thursday, though some IFR fog at LWB possible
late tonight.

Forecast confidence is average.

AVIATION OUTLOOK...

Mainly VFR outside storms and fog/low stratus mornings.

Sunday is the most likely to have no flight restrictions due to
showers and thunderstorms.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Heat Advisory until 8 PM EDT this evening for VAZ033-034-
     043>047-058-059.
NC...Heat Advisory until 8 PM EDT this evening for NCZ005-006.
WV...None.

&&

$$

SYNOPSIS...AMS/WP
NEAR TERM...WP
SHORT TERM...SH
LONG TERM...SH
AVIATION...AS/WP