564 
FXUS61 KRLX 260008
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
808 PM EDT Fri May 25 2018

.SYNOPSIS...
Weak upper level disturbance crosses overnight. Stronger upper 
level trough crosses Saturday into Sunday. Dry per high pressure
for Memorial Day. Unsettled weather should return by mid week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 805 PM Friday...

Forecast on track, with widely scattered showers mainly east of
the Ohio River, and lightning activity all but gone.

As of 615 PM Friday...

Made adjustments to overnight PoPs based on latest trends and
near term guidance, which reflects the chance for showers 
through the night in and near the mountains per mid level 
weakness and upper level divergence. The essence of the
forecast is largely unchanged.

As of 225 PM Friday...

Cumulus field is building this afternoon, but from visible
satellite imagery, it is apparent that the relatively shallow
saturated layer is having a head time feeding vertical 
development. Some small showers have popped over the Tug Fork 
Valley, and expect more coverage, especially in the mountains 
over the next few hours this evening. Some thunder is possible, 
but again, the dry air in the mid levels is going to be 
inhibitive to a large degree.

Higher dewpoints are leading to milder overnight lows tonight.

Expect an increase in rain chances early Saturday with the 
approach of the open wave aloft moving into the middle Ohio 
Valley, so the increase in POPs is not completely dependent on 
heating tomorrow. Coverage should increase with the added 
instability and moisture depth increases region wide. Lots of 
general thunder potential for the entire eastern third of the 
CONUS on Saturday.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 240 PM Friday

With a good feed of Gulf moisture and an upper level trough moving 
through, expect showers and thunderstorms to drift through Saturday 
night and Sunday. By Sunday night, and especially Monday, we are in 
the dead area between the northern and southern streams which should 
limit showers and storms. Still, with decent moisture kept some low 
end POPs in, mainly across the south and east. Temperatures will 
remain above normal. Stuck close to a consensus blend.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 240 PM Friday...

The pattern is a bit messy for the long term. Initially a cold front 
will try to sink in from the north while the remnants of what 
becomes of sub-tropical storm Alberto begin moving north out of the 
Gulf. Run-to-run and model-to-model consistency is rather low on the 
evolution of this resulting in minimal confidence. Due to this, 
stuck very close to a consensus blend which brings slightly higher 
POPs each day Tuesday through Thursday as the remnants drift 
through. The threat for flooding and strong to severe storms will 
highly depend on the track of these features. Continued showers and 
storms are possible Friday with an upper level system somewhere in 
the Great Lakes region.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
As of 805 PM Friday...

Widely scattered showers mainly along and east of the Ohio 
River will decrease in coverage after sunset, but a weak upper 
level disturbance will keep a low chance going overnight, 
mainly in and near the WV mountains.

Clouds and a weak low level jet should prevent widespread
valley fog overnight, but MVFR valley fog is coded up per 
guidance consensus, with higher dew points compared with last 
night. Overnight and early morning IFR fog is possible, 
especially if a shower or thunderstorm directly impacts a TAF 
site, although the early evening showers that skirted by HTS and
BKW look like they will not enhance overnight fog there much.

A stronger upper level disturbance, and ongoing low to mid level
northward moisture transport, will lead to more numerous showers
and thunderstorms on Saturday, starting early. This has been 
explicitly coded in the TAFS, although amendments may still be 
needed for flight restrictions as convection patterns form.

Light south to southwest surface flow will continue, beneath
light west to southwest flow aloft.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
     
FORECAST CONFIDENCE: Medium to High.

ALTERNATE SCENARIOS: Terminals that get rain see brief IFR with
it, and then in IFR fog overnight and early Saturday morning. 
May need to add TSRA and flight restrictions for numerous cells
on Saturday.

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.

DATE                                                            FRI 05/25/18
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EDT 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    L
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M

AFTER 00Z SUNDAY...
No widespread IFR expected.

&&

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

&&

$$
SYNOPSIS...TRM/MZ/26
NEAR TERM...TRM/26
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...TRM