-- Discussion containing changed information from previous version are highlighted. --
126
FXUS61 KRNK 151812
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
212 PM EDT Sun Sep 15 2024

.SYNOPSIS...
-- Changed Discussion --
High pressure will continue to cover the Mid Atlantic region
through this evening, as a low develops off the Carolina coast.
This low will track through Virginia Tuesday and Wednesday,
bringing rain to much of the area. Low pressure nearby may keep
a few showers around into late week.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH MONDAY/...
As of 130 PM EDT Sunday...

Key Messages:

1. Dry, but breezy conditions continue through Monday afternoon.
2. Chances for rain increase over the Piedmont and Southside Monday
afternoon/evening.

High pressure centered over New England will maintain its hold over
the region through at least Monday morning, with its wedge of
dry air pushing southward into the area. Low stratus will slowly
erode this afternoon east of the Blue Ridge, but not
completely, and skies will continue to be partly to mostly
cloudy in the east, with persistent northeasterly winds. Drier
air to the west will keep skies clearer over southeast WV and
the Allegheny Highlands of VA through today. Breezy winds
continue today and through tomorrow, as the pressure gradient
tightens between the high pressure to the north of the area and
the developing low pressure off the coast of the Carolinas. High
clouds will increase over the area tonight and tomorrow, as
this low pressure system moves closer to the coast and
eventually inland. Rain from this system may reach the far
eastern counties of the forecast area as early as Monday
late morning, but more likely to be Monday evening. With the
increase in clouds, expecting high temperatures Monday to be a
few degrees cooler, in the low 70s. Lows will be in the low 50s
in the west and upper 50s to near 60 in the east.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
As of 153 PM EDT Sunday...

Key Messages:

1) A much needed rainfall for the area Monday night-Tuesday.

2) Some locally heavy rain may cause isolated flooding issues, but
dry conditions overall should prevent most from seeing water issues,
except typical ponding.

3) More scattered coverage Wednesday,

A look at the latest models still shows the GFS as a faster/westward
trend, with some of the high-res model camping in that area as well,
while the NAM/ECM and CMC are in the slower camp.

Despite this, models agree enough that bulk of rainfall is going to
stream in from the Atlantic into our area Monday night into Tuesday
before drifting northward into the mid-Atlantic Wednesday. Should
see most areas get measurable rainfall out of this, but still having
to hedge pops as there are still timing differences/track
differences. Appears along/east of the Blue Ridge could get 1-3
inches of rain with lesser amounts over WV during the Monday-Wed
period but most of that falls late Monday night into Tuesday.

This surface low stays non-tropical per latest NHC discussion but
should bring some gusty northeast/east winds in Monday night-
Tuesday. A few gusts over 30 mph likely in the higher ridges and
portions of the Piedmont before this low weakens Tue afternoon.
Could very well see some limbs/weaker trees fall down. The drought
has also brought stress on some trees/leaves and have some colors
and dying leaves in the mountains, which this wind may likely blow
off.

Beyond Tuesday the surface low occludes across central VA but as
upper low will be overhead, scattered showers/few storms are
expected mainly in the afternoon.

With clouds/rain and breezy conditions will likely see highs running
5 to 10 degrees below normal Tuesday with 60s in the mountains to
lower 70s piedmont. Lows stay near to above normal due to clouds
with lows in the mid to upper 50s in the west to lower 60s east.

Wednesday may see slightly warmer temps with a little more sunshine
with upper 60s to lower 70s mountains to mid to upper 70s east.

Forecast confidence is average on pops/qpf but above average on
temps/sky cover/winds.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 1132 AM EDT Sunday...

Key Message:

1) Model disagreement leads to low confidence forecast especially in
terms of rain chances.

All models are in quite a big disagreement in the extended as to
where the upper low/trough will be and the upper ridge. With much
disagreement between models and their ensembles, leaned toward
persistence and the blend of models which keeps a daily chance
of showers, maybe a storm or two with some semblance of an upper
trough overhead or just east and a baroclinic zone along the
coast. Overall pattern favors low pops and mainly in the
afternoons, with clouds more at night and mix of clouds and
sunshine during the day. This will lead to highs closer to
normal or slightly below and at or above normal.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 150 PM EDT Sunday...

For this afternoon, a mix of VFR and MVFR ceilings prevail, with
mostly VFR in the northwestern counties of the forecast area, in
southeast WV and VA Alleghany Highlands, and MVFR along the
higher elevations of the Blue Ridge and eastward. Clouds have
been eroding through the morning, and will continue to do so
through the afternoon/evening. However, high level clouds will
increase over the area through the overnight and Monday morning
over the Piedmont and Foothills, as a low pressure system moves
towards the Carolinas. Low clouds will build back into the area from
the east, and cloud cover will increase, around or about 14Z,
as the system draws nearer. Generally northeasterly winds stay
breezy overnight, with gusts 15 to 25 knots continuing through
at least 00Z Monday. Winds become gusty again early Monday
morning, gusts between 20 to 25 knots are possible for KDAN and
KLYH, as well as the along the Blue Ridge, after 12Z.

With clearer skies over parts of WV, thinking potential is higher
for patchy fog to develop over the river valleys, so have included
BR for a few hours Monday morning for KLWB. However, confidence is
low, since winds may be strong enough to keep the atmosphere well
mixed. Some areas of lower visibilities due to fog or low clouds are
possible over the ridgetops over the southern Blue Ridge as well.

Light rain from the system may reach the VA and NC Piedmont as early
as Monday afternoon, but more likely after the end of the current
TAF period, ending at 18Z Monday. Therefore, with low confidence in
timing of rain, have opted to leave out of the local TAFs at this
time.

Forecast confidence is average, but low on fog formation and
timing of precipitation.

EXTENDED AVIATION OUTLOOK...

Periods of sub VFR conditions are possible through Thursday, as a
low pressure system brings rain and clouds to the area through the
midweek. The most likely timeframe for rain is Tuesday.

&&

.EQUIPMENT...
As of 145 PM EDT Sunday...

The Lynchburg ASOS (LYH) is still experiencing data transmission
issues, mainly at night. Please use caution when using data
from this site, as some may be missing. Technicians continue to
investigate the problem. No estimated date for return to full
service at this time.

&&

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

&&

$$

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