-- Discussion containing changed information from previous version are highlighted. --
095
FXUS61 KRNK 151539
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
1139 AM EDT Sun Sep 15 2024

.SYNOPSIS...
High pressure will continue to cover the Mid Atlantic region today
and Monday as a low develops off the Carolina coast. This low will
track through Virginia Tuesday and Wednesday bringing rain to much
of the area. The chance of rain will linger through the end of the
week, even as the low moves offshore.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1000 AM EDT Sunday...

Key Message:

    - Little to no rain today and tonight


Low stratus clouds remain over the Piedmont and VA Southside
this morning, while decent clearing is observed over southeast
WV and the Alleghany Highlands, where there is a large area of
drier air in the mid levels, as indicated by the morning
sounding at RNK. Expecting today will be similar to yesterday in
terms of temperature and cloud cover. No significant forecast changes
made for this morning update.

Previous discussion below...


As of 245 AM EDT Sunday...

No significant changes in the surface and upper air pattern
today and tonight. At the surface, a well-defined wedge of high
pressure extended from New England into the southern
Appalachians. Low pressure was deepening off the Southeast
coast. Evening soundings showed easterly wind through a deep
layer of the atmosphere. Water vapor satellite images depicted a
large pocket of mid level dry air over the Ohio Valley.

Low clouds were filling in early this morning in the wedge.
Bufkit forecast soundings, as well as Hi-Res models have these
clouds eroding during the afternoon, only to redevelop again
tonight. There was a notable sharp western edge to the clouds
over southeast West Virginia, aligning with the drier air aloft
and lower surface dew points on the western downslope side of
the central Appalachians.

All of this cloud cover will limit heating today. Temperatures
will be starting out in the mid 50s to mid 60s. So even with
sporadic heating, highs will reach the lower 60s to upper 70s
which is slightly below normal. Will use persistence as guidance
for tonight`s lows.

Rain will approaching the area from the southeast late tonight.
Confidence in the timing and location is low. Have used a blend of
WPC/NBM to have a slight chance of rain in northern North Carolina
just before sunrise.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
As of 200 AM EDT Sunday...

Key Messages:

1) Confidence is rising for rain with heavier downpours possible
east of the Blue Ridge during Monday night and Tuesday.

2) Temperatures will remain below normal due to rain and cloud cover
through Tuesday.

While high pressure remains wedged against the eastern slopes of the
Blue Ridge on Monday, an area of low pressure should continue to
develop off the South Carolina coast. Eventually, this area of low
pressure should move northward into eastern North Carolina by Monday
night and approach Virginia on Tuesday. The models still show a
notable amount of differences with the exact track, which results in
lower confidence of rainfall amounts. Nevertheless, rain chances
will increase during Monday and Monday night. The heaviest rainfall
amounts appear to be east of the Blue Ridge. If enough heavy
rainfall transpires during Monday night into Tuesday, it could cause
a marginal risk of flooding, but the ongoing drought certainly
limits this potential threat.

The area of low pressure could weaken and stall somewhere across the
Mid Atlantic by Wednesday. By that point, an upper level ridge will
build across the Great Lakes, which will block anything escaping
further to the north. Lingering chances of showers should persist
through Wednesday. Temperatures will likely stay below normal for
Monday and Tuesday due to the northeast flow along with increased
cloud cover and rain chances, but there may be a little bit of
warming towards Wednesday as the flow will no longer be out of the
northeast. The surface low could weaken enough to where there is
only an upper level trough lingering overhead on Wednesday.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
As of 645 AM EDT Sunday...

No significant changes in the surface and upper air pattern today
and tonight. At the surface, a well-defined wedge of high pressure
extended from New England into the southern Appalachians. Low
pressure was deepening off the Southeast coast. Evening soundings
showed easterly wind through a deep layer of the atmosphere. Water
vapor satellite images depicted a large pocket of mid level dry air
over the Ohio Valley.

IFR to MVFR clouds were had filled in east of the Blue Ridge. Bufkit
forecast soundings, as well as Hi- Res models have these clouds
lifting to MVFR/VFR later this morning, then eroding during the
afternoon, only to redevelop again tonight. Have KBCB, KROA,
KLYH, and KDAN back down to MVFR/IFR around 07Z/3AM.

Rain will approaching the area from the southeast late tonight.
Confidence in the timing and location is low. Have used a blend of
WPC/NBM to have a slight chance of rain in northern North Carolina
just before sunrise. Rain will stay south of the local TAF sites
through the end of the 12Z/8AM TAF forecast period.

Winds will continue from the east today and tonight with
occasional gusts from 15 to 25 kts, especially in the
mountains.

Average confidence for visibility and wind.
Below average confidence for ceiling, as well as timing and
location of rain.

EXTENDED AVIATION OUTLOOK...

Sub-VFR at times tonight through Thursday as coastal system
impacts our area with rain at times. The most likely time frame
for rain is on Tuesday.

&&

.EQUIPMENT...
As of 120 PM EDT Saturday...

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 are
investigating the problem.

&&

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

&&

$$

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