-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 191643
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
1243 PM EDT Sat Aug 19 2017

.SYNOPSIS...
A front will remain over the Carolinas today into Sunday before
dissipating. High pressure works in from the Ohio Valley during
the weekend, then overhead Monday resulting in drier weather
across the region.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 950 AM EDT Saturday...

Surface front has slipped just east of the region this morning
allowing drier air to filter in per drop in PWATS off observed
12Z raobs and latest Blended TPW. However still have a trailing
upper system now approaching the Ohio valley to cross the
region this evening, with the majority of moisture with this
feature progged to stay just north of the CWA. This still
supported by most short term solutions espcly given degree of
dry air seen aloft so will keep things dry through the
afternoon. Otherwise expect some added clouds espcly mountains
with heating although appears dry entrainment may limit
coverage to mainly the northwest third for now. Given lingering
warm air aloft combined with heating of somewhat drier air under
weak eastern downslope, expect highs to again be around 90 east
and into the 80s west. Thus bumped up highs a degree or two
across the region for the afternoon.


Previous discussion as of 308 AM EDT Saturday...

Sfc front across the piedmont this morning with high pressure over
eastern TN. Deeper moisture is east of the CWA with axis of
upper trough progged to move across this evening. Moisture
profile showing drier air per model soundings and WV trends.
Shower threat today will be limited to WV at best closer to the
better lift, with scant cu across the rest of the area.

Since not much change in airmass temps should close to or maybe a
couple degrees cooler than the past day, and dewpoints given some
westerly flow should drop to the upper 50s to mid 60s.

Tonight, clear skies as surface high shifts overhead. Lows will be
closer to normal with upper 50s to lower 60s west, to mid to upper
60s east.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM EDT Saturday...

An upper level trough will rotate east into the Atlantic ocean
Sunday, followed by a weak zonal flow which continues into Monday
night. High pressure will build across our region Sunday into Sunday
night. High temperatures Sunday will be above normal with readings
from the upper 70s in the mountains to the lower 90s in the
piedmont. Drier air with dewpoints generally in the 60s will be a
welcome change. Look for a pleasant Sunday night with low
temperatures from around 60 degrees in the west to around 70 degrees
in the east.

High pressure with increasing heights aloft will continue Monday
through Monday night. The combination of solar heating, low level
moisture and upslope flow may generate a few showers or
thunderstorms across the mountain. The North Carolina High Country
will have the best chances late in the afternoon. Any convection
will fade in the evening with the loss of solar heating.

Under plenty of sunshine, high temperatures Monday will vary from
the lower 80s in the west to the lower 90s in the east. Low
temperatures Monday night will generally be from the lower 60s in
the mountains to the lower 70s in the east.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 300 AM EDT Saturday...


A western Atlantic upper level ridge will track westward over the
Gulf states through early next week. This ridge will push
temperatures 5F to 10F warmer than normal. With an increase in heat
and humidity, scattered showers and thunderstorms are expected
Tuesday afternoon across the mountains and then moving and fading
across the foothills in the evening.

On Wednesday, models are wanting to bring a cold front south into
the Gulf states, pushing the upper level ridge into the Gulf.
Considering climatology for the time of year, models look to be over
zealous with moving this front into a hot and humid air mass. I
would not be surprised to see a slowing trend with the frontal
passage being more towards Thursday. For now, kept timing close to
guidance while keeping PoPs low. Until the front clears the area,
temperatures will stay 5F to 10F warmer normal. Following the front,
temperatures will be 5F or cooler than normal.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 1240 PM EDT Saturday...

Expect any lingering MVFR cigs over the mountains to finally
lift or scatter out early this afternoon making for overall VFR
conditions into this evening. Winds will be mainly from the
west/northwest around 10 kts except for a few gusts to near
20 kts along the ridges.

Weak disturbance passes this evening with any residual cumulus
fading overnight as high pressure builds in from the northwest.
This may allow areas of fog and stratus to develop late tonight
espcly in the valley locations and possibly across the eastern
terminals. Think KLWB/KBCB have the best shot at seeing a period
of IFR/LIFR, while some late night IFR/MVFR could occur at KBLF,
with MVFR around KLYH/KDAN. Otherwise VFR under light winds.

Any fog/stratus should dissipate by mid morning Sunday allowing
for a return to overall VFR again under scattered to perhaps
broken cumulus over parts of the mountains. An isolated shower
could occur mainly along the southern Blue Ridge later Sunday
otherwise VFR under light winds.

Extended Aviation Discussion...

Moisture will gradually start to return early next week as high
pressure weakens and moves offshore ahead of another cold front
that should arrive from the northwest around midweek. However
still appears should remain mainly VFR Monday into Tuesday with
localized MVFR under isolated to widely scattered convection.
Late night/early morning fog will also be possible each day.
Better potential for sub- VFR will come Wednesday when possibly
more widespread showers and storms arrive with the next cold
front.
-- End Changed Discussion --

&&

.EQUIPMENT...
As of 400 AM EDT Friday Aug 18th...

KFCX doppler radar expected to be down for the rest of the
month due to a failing bull gear. Technicians are working on the
radar, through next week and the radar will most likely stay
down completely as the repairs are being made.

&&

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

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH/WP
SHORT TERM...KK
LONG TERM...KK/RCS
AVIATION...JH
EQUIPMENT...RAB/WERT/WP