174
FXUS61 KRNK 141732
AFDRNK

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

.SYNOPSIS...
A low pressure system will cross the Mid Atlantic through Wednesday
to bring showers and scattered thunderstorms. Weak high
pressure should provide drier air for Thursday, but another low
pressure system will bring more rain for the end of this week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
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 230 AM EDT Tuesday...

Key Messages:

1. Showers and possible storms on Wednesday.
2. Drier weather Thursday.
3. Shower and storm chances increase again Friday.

By Wednesday morning, a low pressure system will be over most of the
Mid Atlantic region, with a warm front extending west to east across
VA and NC, and a cold front along the southeastern coast. Some
showers may be lingering over the western slopes by the start of
this forecast period, as moisture wraps around the low back into the
area. Coverage of showers will increase through the day Wednesday,
and some thunderstorms are possible by Wednesday afternoon as
instability increases with daytime heating and the passage of the
upper shortwave. Deep layer shear is forecast to be between 30 and
40 knots over the Carolinas, which would be supportive of multicell
thunderstorms, and if coinciding with the peak heating, and
thus greatest instability, storms could become severe. Above
normal precipitable water values are forecast, so localized
heavy rainfall is possible. Showers and storms decrease
Wednesday night as the surface low moves offshore, and mid level
ridging will build overhead by Thursday, bringing a brief
reprieve from the rain.

The next low pressure system approaches the Ohio Valley by Friday,
and showers could begin for the western counties in the forecast
area as early as Friday afternoon, although notable differences
in timing are still present in the long range deterministic
models. The 500mb shortwave crosses the area by late Friday,
increasing chances for thunderstorms Friday afternoon. With the
discrepancies in the models, there is still plenty of
uncertainty in the arrival and location of the heaviest rainfall
for the end of the week.

Temperatures will trend warmer through this forecast period,
although plenty of cloud cover will keep highs in the 60s and 70s
for Wednesday, but warming a few degrees for Thursday and Friday.
Lows will be mild, generally in the 50s and low 60s each night.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 230 AM EDT Tuesday...


Key Messages:

1. Unsettled weather to start the weekend, drier weather to start
the work week.
2. Near normal temperatures Saturday, warming to a few degrees above
normal by Monday.

Another upper trough and low pressure system approaches the Ohio
Valley by the end of the work week, reaching the Mid Atlantic and
central Appalachians by the start of the weekend. As mentioned in
the short term forecast discussion, there are still discrepancies in
the timing of this system and the placement of its associated
fronts, so showers may be ongoing at the start of the long term
forecast period, and increase in coverage by Saturday afternoon and
evening. Storms are possible Saturday afternoon as instability
increases with daytime heating. Most of the deterministic models
show the low departing offshore by Sunday, and mid level ridging
returning to the area by Monday, so at this time, thinking drier
weather for the end of the weekend and beginning of the work week.

Temperatures will be near normal for Saturday, warming to a few
degrees above normal by Monday.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
As of 130 PM EDT Tuesday...

Sub VFR flying conditions can be expected for the 24hr TAF
period. Widely scattered showers will continue into the early
overnight hours, along with low cigs. Areas of dense fog
development seem probable tonight as well. All terminals
tonight will have periods of IFR/LIFR. Some slight improvements
tomorrow by late morning as morning fog dissipates and cigs
raise, but IFR to MVFR still likely to persist to the end of
the valid 24hr period.

Extended Aviation Outlook...

Poor flying conditions will continue into Wednesday as a cold
front approaches from the west. Scattered showers and
thunderstorms should continue through Wednesday evening but
start to fade by Wednesday night as the cold front exits. VFR
conditions should return for most terminals by Thursday due to
weak high pressure passing to the north. However, another low
pressure system could arrive during Friday afternoon into
Saturday to bring low ceilings and scattered showers and
thunderstorms.

&&

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

&&

$$

SYNOPSIS...BMG
NEAR TERM...BMG
SHORT TERM...AS
LONG TERM...AS
AVIATION...BMG