-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 241400
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
1000 AM EDT Mon Jul 24 2017

.SYNOPSIS...
A weak cold front across the Ohio Valley will slide southeast
toward the region this afternoon before slipping south into the
Carolinas late tonight and early Tuesday. High pressure works
east across the Great Lakes into New England Tuesday through
Wednesday behind the front with our temperatures returning
closer to normal. Another cold front approaches from the
northwest on Friday.
&&

.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM EDT Monday...

Much of the region has slipped into drier air aloft this morning
between the residual outflow/trough axis in the foothills and
the actual upstream cold front still lagging back in the Ohio
Valley. This seen via lower PWATS off the morning RNK sounding
vs the wetter GSO raob, and the latest water vapor loop showing
much drier air aloft to the northwest. Latest short term
guidance still remains on the dry side given lack of much
forcing until the front to the northwest gets closer. Also
expected mixing down of drier air aloft this afternoon should
help dewpoints lower from west to east as the low level flow
veers more westerly out east.

However still cant completely rule out an isolated storm
developing southeast pending location of the lee trough, and
across the northwest where some weak convergence will develop
late along the axis of instability over West Va. This supports
adding in some isolated pops far west later on while keeping a
mention southeast where expect overall coverage of deeper
convection to remain to the south. Otrw appears enough surface-
7h northwest flow to help skies become sunny by afternoon per
dry entrainment, with only some low clouds persisting a bit
longer northwest slopes where aided by weak upslope. Kept highs
a little above guidance east, low/mid 90s, as weak downslope kicks
in with heating, while maintaining thickness supported
mid/upper 80s west for now.


Previous discussion as of 324 AM EDT Monday...

Area of showers and storms have weakened east of the Blue Ridge
early this morning with residual showers back over Southeast WV into
the NC mountains behind sfc trough. Will see less coverage today as
deeper moisture shift southeast with front arriving across the
central Appalachians. SPC has pretty much cleared the area of severe
threat and most models are in agreement on limited coverage, with
isolated across the WV mountains with frontal convergence and in the
far eastern CWA closer to lee trough and deeper moisture.

Expect a little lower humidity today with west winds still providing
a very warm day with highs ranging from the 80s west, to lower to
mid 90s east.

Tonight, axis of upper trough exits east while sfc front slides
south into NC. Question remains how far south the front goes along
with deep moisture. Appears any convection this afternoon should
fade by mid evening. Skies stay clear to partly cloudy with lows in
the 60s west, to lower 70s east.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
As of 325 AM EDT Monday...

Looking a little drier Tue-Wed with northwest flow aloft and
rising heights while sfc high wedges southward into our area from
the northeast. Still could see some isolated showers or storms in
the southern Blue Ridge and NC foothills/piedmont Tue, then a little
more southeast flow may allow for convection Wednesday to fire
further north along the Blue Ridge and foothills but confidence is
low as latest models are trending drier.

Return flow continues a little more Thursday ahead of next front
moving into the Ohio Valley, but appears coverage will be isolated
to widely scattered.

Temperature will be close to normal this period, which is a little
cooler than what we have been experiencing.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
As of 1100 AM EDT Sunday...

A cold front will make its way across the mid Atlantic on
Friday, triggering more organized/widespread shower and
thunderstorm activity. Latest run of the weather forecast models
indicate that the front will clear our area to the south by
Saturday morning, bringing drier air in its wake. Have therefore
lowered rain chances for next weekend, though isolated
showers/storms cannot be ruled out.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
As of 707 AM EDT Monday...

LIFR/IFR cigs BLF/LWB should scatter out 14-15z. VFR expected
all sites afterwards with isolated convection possible, though
not expecting any at the taf sites, closest per model solutions
would be LWB and LYH.

Winds will remain WSW-WNW 5-10kts through most of the TAF valid
period.

Could see some fog late tonight, mainly LWB/BCB, but at the
moment leaving it out as we dry out today.

Aviation Extended Discussion...

A frontal boundary should stall to the south, with high
pressure wedging southward on Wednesday. Overall VFR but with
flow turning more east, this could bring some MVFR/IFR
ceilings, which should quickly vanish by Thursday. Next best
threat for showers and storms arrives with another front Friday.

&&

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

&&

$$
SYNOPSIS...JH/PW/WP
NEAR TERM...JH/WP
SHORT TERM...WP
LONG TERM...NF
AVIATION...RAB/WP