655
FXUS61 KRNK 120755
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
355 AM EDT Fri Jul 12 2024

.SYNOPSIS...
A front along the East Coast drifts back to the west today as
low pressure tracks along the boundary. This will bring
widespread rain to parts of central and eastern Virginia and
North Carolina. The front should retreat further east for
Saturday and limit precip chances to parts of the east and
south. Sunday looks mostly dry. Afternoon thunderstorm chances
return Monday through Tuesday, while another system brings more
widespread rain towards the middle of next week. Temperatures
will be cooler today but increase again for the weekend, with
heat index values approaching 100 degrees in Piedmont again for
much of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM EDT Friday...

Key Message:

1. Shower and storm chances on the increase today.

Frontal boundary and enhanced deep layer moisture axis is advecting
westward into the eastern CWA this morning and already triggering
some shower development. Expecting the trend to continue into today
with increased shower and thunderstorm potential for mainly the
eastern two thirds of the area and have likely to categorical pops
mainly along and east of the Blue Ridge. PWATs should increase to
greater than 2 inches so any convection should be quite precip
efficient with hydrometeor loading and localized heavy rainfall. For
now thinking QPF amounts of mainly a half to 1.5 inches in parts of
the Piedmont should be maintainable and welcomed in the dry
antecedent conditions, though will need to be monitored if higher
amounts may warrant any increased chance of a flood watch. By
tonight into early Saturday the aforementioned front and moisture
axis should meander back east and allow for a gradual decrease in
convective coverage.

Temps today will be limited due to the precip and cloud coverage so
highs are actually only expected to make it to the low 80s for much
of the area.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 300 AM EDT Friday...

Key Messages:

1. Above normal temperatures Saturday and Sunday.
2. Increasing confidence for drier weather over the weekend.

By the start of the weekend, a ridge of high pressure aloft over the
Atlantic starts to shift east, and expands farther across the
southeastern US, while ridging develops over the Rockies. A weak
upper trough digs southward into the Mid Atlantic through the
weekend, but eventually flattens out by Sunday. At the surface, a
stationary front situated north-south lingers along the eastern US
coast through Saturday, and will be the focus for showers and
thunderstorms. How far west the shower and storm activity will
expand is uncertain at this time, as most guidance shows mostly
westerly and northwesterly winds across the area, which is usually
unfavorable for thunderstorm development in the Piedmont, so most of
the showers and thunderstorms looks to be over eastern VA and NC,
although a few isolated showers and storms can`t be ruled out in the
Southside by the afternoon Saturday. By Sunday, this front will move
farther from the area, decreasing precipitation chances even farther
areawide, though diurnal heating and increasing moisture may spark
some isolated showers and storms mid afternoon.

Return flow around surface high pressure over the Atlantic will
contribute to increasing moisture over the area through Saturday,
and an increase in dewpoints, and precipitable water values exceed
the 99th percentile relative to climatology by late Saturday,
especially over eastern VA and NC. Temperatures start increasing
again to above normal values, making for a hot weekend ahead.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 300 AM EDT Friday...

Key Messages:

1. Above normal temperatures continue through midweek.
2. Increasing chances for showers and storms by Wednesday.

A 500mb ridge expands into the Mid Atlantic from the west to start
the work week, and surface high pressure builds over the
southeastern and Mid Atlantic states, which will keep the weather
mostly dry over the area through at least the beginning of the work
week. Afternoon showers and thunderstorms are possible during the
afternoons with peak daytime heating, mainly along the higher
terrain, due to orographic forcing. With subsidence from the high
pressure overhead, hot, above normal temperatures will continue
through at least midweek. A strong cold front drops southward into
the area from the Great Lakes region Wednesday or Thursday, which
will bring increased probabilities of more widespread coverage of
showers and thunderstorms. With better forcing and wind shear from
stronger front, there is greater probabilities of more severe
thunderstorms, but, that being said, mesoscale details are too
uncertain at this time frame to give specifics. Overall, the middle
of the week looks to have more active weather at this time.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
As of 130 AM EDT Friday...

Cigs should lower into the MVFR/IFR range later this morning
along with increased shower chances for the eastern sites. Have
TS potential by late morning into afternoon. Coverage of precip
should be less farther west along with VFR conditions - maybe
just some alto clouds or cu 4-7 kft. Winds should be generally
NE to east under 10 kts. Tonight into Saturday morning could
have some reduced MVFR vsbys and LIFR cigs for the east and
possible MVFR cigs or lower for the central sites.

Forecast confidence is medium on western extent of precip
coverage and cigs.

AVIATION OUTLOOK...

The weekend looks drier with morning fog possible. Afternoon
TSRA chances increasing again Monday.

&&

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

&&

$$

SYNOPSIS...SH/AB
NEAR TERM...AB
SHORT TERM...AS
LONG TERM...AS
AVIATION...SH/AB