541
FXUS61 KRNK 150048
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
848 PM EDT Tue May 14 2024

.SYNOPSIS...
A low pressure system will cross the Mid Atlantic through
Wednesday, and bring showers and scattered thunderstorms to our
area. Weak high pressure should allow drier weather conditions
to be seen Thursday, but another low pressure system is expected
to bring more rain to the region for the end of this week.

&&

.NEAR TERM /NOW THROUGH WEDNESDAY/...
Issued at 848 PM EDT Tue May 14 2024

A large area of rain continues to shift northeastward across the
region this evening, as a shortwave trough swings through the
area. Additional showers will likely be seen overnight, as
additional energy (ahead of the main upper low spinning across
the Mid- Mississippi Valley) passes through the region and
interacts with a moist airmass draped over the forecast area.
The ongoing forecast grids seem to have a decent handle on the
timing and possibility of any precipitation overnight.

The big weather story overnight will likely be the development
of fog overnight. Some of the fog could be locally dense, thanks
to the rainfall seen for much of the day. I`ll continue to
monitor observational trends for now, but I wouldn`t be
surprised if I didn`t issue a Special Weather Statement to
increase the visibility/messaging for locally dense fog before
the end of my shift.

Otherwise, the forecast appears to be on track for the time
being.

As of 130 PM EDT Tuesday...

Key Messages:

1) Rain showers to continue through the evening and overnight
hours.

2) Areas of dense fog tonight.

3) Widely scattered thunderstorms tomorrow.

Widely scattered showers are ongoing this afternoon as an upper
wave pivots northeast ahead of a the main upper low centered
over southern Missouri. Rain is expected to increase in coverage
and possibly in intensity through the evening hours. The main
axis of rainfall looks to fall along the Foothills and east into
the Piedmont. Rain will taper off tonight and become more
isolated. Precipitable Water values continue to increase with
southerly flow. RAP analysis indicated 1.4" to 1.6" has made it
into the region, therefore some heavy downpours will be
possible. Fortunately, not expecting prolonged training or
convection so any flooding threat is low.

With plenty of moisture, expecting fog to develop overnight and
could be dense in some areas. Lows tonight remain mild in the
upper 50s to low 60s.

Upper low, expected to become an open wave as it moves east
tomorrow. Will cross during peak heating, but some uncertainty
lies on how much cloud cover will persist, which in turn will
limit heating/destabilization. Deep moisture is in place, but
shear is limited, therefore not expecting organized convection.
Most likely area to see breaks in the clouds will be across the
mountains and this would coincide with where the best coverage
of storms appears to occur, based off 12z CAM guidance. Owing to
weak shear, multicellular/merging pulse storms seem to be the
most likely storm mode tomorrow. Capable of a few instances of
damaging wind and perhaps some hail.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 125 PM EDT Tuesday...

Key message:

   - Moderate to high confidence of more rainfall Friday and Friday
     night

Wednesday night and Thursday the upper trough and surface low move
east off the Mid Atlantic and Carolina coast, bringing low
level and surface wind around to the northwest then north. This
will limit the probability of precipitation to the mountains.
Some clearing is expected in the piedmont Thursday afternoon.

Surface high pressure will cover the area overnight Thursday
and Friday morning. This break in widespread rain will be brief.
Another low pressure system will approach from the central
United States. Showers and thunderstorms reach the central and
southern Appalachians by Friday afternoon and the piedmont
before Friday night.

Models showed good consensus with the synoptic pattern in this time
frame. Despite the low and cold front crossing the area on
Wednesday night, there will be little noticeable change in the
overall airmass. Lows through the Friday night will be mild,
generally 5 to 15 degrees above normal. Highs on Thursday and Friday
will be near to slightly above normal.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 130 PM EDT Tuesday...

Key messages:

   - Moderate confidence that wet weather will continue Saturday
   - Monday and Tuesday may be dry, confidence lower.

The bulk of this next system comes through the region on
Saturday. A cold front will provide enhanced lift. Behind this
low, mean flow turns to the northwest, confining precipitation
to the mountains. Best chance of showers and thunderstorms will
be on Sunday with daytime heating. Pattern will follow a more
diurnal cycle with less rainfall overnight. Monday and Tuesday
will have the most likely chance to be dry during the day. Still
no significant chance in airmass or high and low temperatures
through Tuesday.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Issued at 848 PM EDT Tue May 14 2024

The bottom line -- expect poor flying conditions to continue
through 15/2400 UTC. Low CIGs, and likely low VSBYs, will lead
to the development of widespread IFR/LIFR flight categories
overnight across area terminals. Additional energy rotating
through the region will result in some SCTD -SHRA being seen
overnight, with areas of BR/FG expected. Some improvement -
likely only to MVFR - is anticipated after 15/1300 UTC as the
BR/FG dissipates and CIGs improve. However, additional SHRA, and
possibly some TSRA, should develop after 15/1800 UTC. My
confidence (or lack thereof) in the timing and location of any
TS precluded any mention in the 15/0000 UTC TAF package.

OUTLOOK WEDNESDAY NIGHT THROUGH SUNDAY...

Wednesday night: Flight restrictions expected to continue due to
lower CIGs/VSBYs in SCTD SHRA/TSRA. Some improvement is possible
late.

Thursday: VFR flight categories expected.

Friday: Deteriorating conditions. Flight restrictions possible
by afternoon due to low CIGs with an increasing coverage of
SHRA/TSRA.

Friday night and Saturday: Flight restrictions expected due to
low CIGs/VSBYs in SHRA/TSRA.

Sunday: Some restrictions possible, especially early, with a
decreasing coverage of SHRA/TSRA.

&&

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

&&

$$

SYNOPSIS...BMG/DB
NEAR TERM...BMG/DB
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...DB