395
FXUS61 KRNK 232342
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
742 PM EDT Sun Jun 23 2024

.SYNOPSIS...
A front crosses the region tonight with a chance for showers
and thunderstorms. Drier weather returns for Monday and Tuesday
with temperatures and humidity gradually increasing again
by Wednesday. The next chance of showers and thunderstorms
arrives on Wednesday afternoon, with the heat again returning
Friday and Saturday.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 730 PM EDT Sunday...

Key Messages:

1. Scattered showers/storms through early overnight with best
chance in the mountains. Small threat of strong/severe storms.

2. Drier and a few degrees cooler Monday.

Pre-frontal trough along with an embedded upper impulse combined
with good heating to generate a few storms in the piedmont this
afternoon. Main front lingers back across the upper Ohio Valley
into the lower TN Valley. This front will likely cross the area
by Monday. Appears models have greater agreement in the
mountains getting a needed rainfall overnight with some storms,
so kept likely pops across southeast WV into the Mountain Empire
tapering to high chance to the New River Valley and low chance
along/east of the Blue Ridge. Severe threat will be limited as
best instability stays well north and west this evening and with
better dynamics staying north as well.

Previous discussion...

Plentiful sunshine today and west-southwesterly surface flow
has helped push temperatures back into the upper 80s and low to
mid 90s. Heat indices are approaching the upper 90s out in the
Piedmont, and near 100 degrees is certainly possible, though
generally staying below Heat Advisory criteria. Scattered
cumulus clouds have developed, especially along and west of the
Blue Ridge, and some higher level clouds are starting to reach
the area from the west. This may impact temperatures in the west
if that cloud cover can thicken enough before diurnal heating
peaks, but thinking plenty of heating before then for the
increase in cloud cover to make much of a cooling difference on
high temperatures this afternoon. Overnight, not thinking a lot
of relief from the heat, with the clouds lingering until
tomorrow morning, as lows only reach the low to mid 60s in the
west and and low 70s in the east. Monday will be a few degrees
cooler than today, with the passage of the cold front. The
biggest difference in temperatures will be felt in the west,
where highs could be five to ten degrees cooler tomorrow than
today, and with a decent northwesterly breeze and drier airmass,
should feel more pleasant. Highs tomorrow in the east will be
in the upper 80s to low 90s, as the front exits the area after
mid morning.

With ample daytime heating today, high res guidance is showing good
surface based instability, especially out in the east.
A few thunderstorms have already developed in the Piedmont this
early afternoon, tapping into the better moisture and
instability. The better forcing is well to the north of the
area, closer to the upper low, so coverage would be isolated to
scattered at best. As the front nears the mountains this evening
and into tonight, storms may develop over the higher terrain
with the additional orographic forcing. Forecast soundings show
an inverted V profile, and decent DCAPE, so the primary threat
continues to be damaging winds.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 100 PM EDT Sunday...

Key Messages:

     - Increasing confidence of lower humidity on Tuesday
     - Next front and thunderstorms on Wednesday

A drier air mass advances into the Mid Atlantic region as the cold
front progresses into the Carolinas. Surface dew points will lower
into the 50s by Tuesday afternoon which will result in a lower heat
index.

Deeper moisture and a higher probability of thunderstorms will
return to the region on Wednesday ahead of the next upper long wave
trough and surface cold front. The best dynamics and jet structure
remain north of the region, so expecting isolated to scattered
coverage of thunderstorms, mainly Wednesday afternoon and evening.

Only plan to deviate from NBM temperature guidance is on Monday
night when surface dew points lower and surface high pressure
directly over the central Appalachians will lead to light and
variable or calm winds. Will lower mins Monday night a few degrees
below guidance.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 100 PM EDT Sunday...

Key Messages:

    - Heat returns for Friday and Saturday
    - Moderate confidence for showers and thunderstorms on Sunday

Thursday and Friday will have a limited threat for showers and
thunderstorms behind the mid week front. The upper pattern returns
to zonal flow with little forcing for any organized probability of
precipitation. The North American Ensemble shows 500MB ridging from
the Southern Plains to the Mid Atlantic region by Saturday with
above normal heights over the Mid Atlantic States. Overall warm
temperatures at mid levels of the atmosphere may create a cap on
thunderstorm development, but by Saturday there will be at least an
isolated threat of thunderstorms, especially near the typically
favored higher elevations.

Long range synoptic scale guidance brings the next cold front
through the region on Sunday. Will keep probability of precipitation
in the chance range until the timing trends with this front become
more consistent.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 730 PM EDT Sunday...

Generally VFR through most of the period. However,
showers/storms around BLF/LWB and perhaps BCB this evening into
overnight could drop cigs/vsbys to IFR. Any showers/storms will
be gone before 11z, with skies clearing Monday morning after
12z.

South to southwest winds under 10kts this evening to shift to
the west/northwest behind the front late tonight into Monday.
Gusts to 20kts possible at all sites during the day Monday.


Forecast confidence is high, except on how low cigs/vsbys get
with storms.



EXTENDED AVIATION OUTLOOK...

VFR conditions expected through much of the week, with the only
exception being areas of valley fog in the early morning hours,
and with any storms Wed-Fri.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$

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