312 
FXUS61 KRLX 252014
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
414 PM EDT Fri Sep 25 2020

.SYNOPSIS...
High pressure this weekend, followed by a strong cold front 
early next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 412 PM Friday...

Speeded up the exodus of light pcpn east of our mountains during
the late afternoon hours per latest radar imagery. Rest of 
forecast remains on track.


As of 215 PM Friday...

Upper trof axis pulls east this evening taking the steady rain
that has affected southeastern WV and southwester VA with it. Dry
air in the mid and upper levels will quickly advect into the 
region in the wake of departing system. However, an abundance of
low level moisture will linger overnight even as surface high 
pressure builds overhead with patchy drizzle possible across the
eastern slopes in the mountains. This will also allow for low 
stratus and areas of dense river valley fog to develop, 
following the initial clearing early this evening. I suspect 
the extent of dense fog expected will eventually warrant an SPS 
this evening or overnight, if not a dense fog advisory, 
especially across northeast KY and southeast OH. 

Low stratus and fog will be especially slow to lift and
dissipate Saturday as inversion lingers. Eventually enough
mixing and warming occur to weaken the inversion for sunshine to
gradually make a return.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 230 PM Friday...

Brief warming in the short term in ridging aloft, ahead of a filling 
upper low in the southern stream that will be pushing northeastward. 
This feature will become weaker as it moves into the area, with only 
a slight increase in moisture. Forecast will be conservative on the 
POPs, but might need to consider low end mountain chances for 
showers Sunday and Sunday night in future forecasts. Upper trough 
digs into the midwest, and southwesterly flow becomes more active, 
necessitating POP increases for the beginning of the work week ahead 
of the cold front. Temperatures above normal in lowland 80s for 
Sunday and Monday.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 230 PM Friday...

Stout cold front plows through in the Monday night/Tuesday time 
frame. Details still coming together on the evolution of the broad 
upper level trough that will become dominant over the eastern CONUS, 
but showers can be expected with the front as well as a significant 
drop in the 850mb temperatures and 1000-500mb thicknesses. May see 
an upper low split from the main flow in its push southward, and 
then merge once again as the main trough amplifies. There may be a 
secondary cold front as a result reinforcing the cooler airmass near 
the end of the long term period.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
As of 220 PM Friday...

System departs this evening taking the rainfall with it. In its
wake, low stratus and areas of dense river valley fog will
develop. This will impact all terminals with IFR, quickly
dropping to VLIFR VSBY/CIGS by 06Z, if not sooner at some
terminals.

Conditions will be slow to improve Saturday...taking until late
morning to lift out of IFR with MVFR BKN stratus likely
lingering into early afternoon.

Surface flow will generally be light and variable throughout. 

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
     
FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: Timing onset and dissipation of low
stratus/dense fog may vary an hour or two from forecast. 

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
HTS CONSISTENCY  L    L    M    H    H    H    H    H    H    H    H    M
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    L    H    L
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    L

AFTER 18Z SATURDAY...
IFR conditions will be possible Sunday morning in dense river
valley fog.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.

&&

$$
SYNOPSIS...26/30
NEAR TERM...ARJ/30
SHORT TERM...26
LONG TERM...26
AVIATION...30