785
FXUS61 KRLX 270837
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
437 AM EDT Fri Sep 27 2024

.SYNOPSIS...
Remnants of Helene arrive this morning, spreading strong gusty
winds and additional rainfall today. More rain chances over the
weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 430 AM Friday...

Key Points:

 * Flash Flood Watch in effect until 8 PM tonight for southwest
   VA, mountains of WV and the Tri-State Area.

 * High Wind Warning in effect until 8 PM tonight across the
   mountains of southwest VA and WV.

 * Wind Advisory in effect until 8 PM tonight for portions of
   the coalfields, foothills and mountains of WV, as well as
   portions of the the Tri-State Area.

A frontal boundary spawning off from the north of Hurricane
Helene is currently over the area. As a result, expecting
showers and gusty winds to impact the area starting early this
morning as Helene tracks north and west into the CONUS. The
center of the remnants will pass to our west over Kentucky this
afternoon/evening.

Helene is weakening quite a bit since making landfall and it
will be a quick moving system. Most of our impacts will be seen
this morning into early afternoon. Some hold over into the
evening is possible with any flooding that may arise.

There is a moderate risk for excessive rainfall across portions
of Dickenson and Buchanan counties in VA and a slight risk of
excessive rainfall across the far southern coalfields and
mountains of West Virginia. Models show the bulk of the rain
falling between 6 AM and 3 PM today, with the highest amounts
between 1.00" and 1.30" across our northeastern KY counties and
southwest VA counties. Did continue and expand the flood watch
accordingly to cover any areas of concern.

The wind threat has been increased with latest short-range
guidance, particularly across the higher ridges of the
mountains. The potential is there with this fast moving storm
as southeast flow becomes enhanced across the ridgetops above
2,500 feet. Used a HREF/HRRR blend which has gusts between 50
and 60 mph for much of the higher elevations this morning, with
some locally higher gusts possible. Did upgrade or add counties
to a high wind warning to cover this. Also expanded the wind
advisory across portions of the lowlands. Did not go with any
short-range bias for the lower elevations as the winds were way
overdone across this area.

There is a chance that the wind factor is less substantial than
advertised if Helene continues to rapidly weaken as it traverses
inland. Otherwise, fairly confident that criteria will be met
across the higher elevations particularly in our southern
mountain counties of WV and southwest VA.

There is a marginal risk for severe weather concerning tornado
risk. This outlook is clipping our VA counties and far eastern
McDowell County up to eastern Fayette and southeast Pocahontas
County. Some stronger cells on the northeastern side of this
system do have the potential for rotation, but the highest risk
remains to our east.

Will start to see winds and some of the shower activity tapering
off this afternoon into the evening as the remnants sit to our
west.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 250 AM Friday...

Key Points:

 * Rain chances will diminish for most on Saturday, but return
   area-wide on Sunday and Monday. Some areas of heavier rain
   could lead to localized water issues.

Between the remnants of Helene briefly heading over towards the
lower Ohio Valley and us getting some downsloping on SE`ly
winds, much of the CWA could be rain-free to start the period
on Saturday, and perhaps even into Saturday night. However, as
the remnant low of Helene then treks back east across Kentucky
on Sunday, moisture across the area will increase and our winds
shift more S`ly, resulting in widespread rain spreading east
across the CWA. There`s also the chance for some embedded
thunderstorms and areas of heavier rain, so WPC does look to
continue the Marginal excessive rainfall risk on Sunday for
most of our counties excepting Ohio.

We expect more area-wide rain on Monday, but the thunderstorm
and heavy rain risk seems more contained to the mountains, which
is matched by WPC limiting Monday`s marginal risk to the
mountains and western upslope areas. There is some disagreement
among the models on the speed at which the upper-level
low/trough will shift east of the area, which would mark the
time we expect a reduction in precip coverage across the
lowlands. Some show it as early as late Monday night, but others
hold off until Tuesday. Thus we maintain at least Chance POPs
across the lowlands through Mon night.

With the potential for some downsloping especially on Saturday,
and perhaps some partly cloudy skies west of the mountains, we
do have highs along the I-79 corridor getting to 80 or even into
the low 80s, but 70s for most of the rest of the lowlands. With
increased cloud cover and precip coverage, highs Sunday and
Monday will be limited to 70s for the lowlands and southern
mountains, and 60s for the central and northern mountains.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 315 AM Friday...

We won`t be done with the precip quite yet, as the departure of
the Helene remnants and upper low will be quickly followed by
another upper-level shortwave trough and surface cold front
later Tuesday into Tuesday night. Thus, we maintain slight
chance to chance POPs across the area on Tuesday, and for most
of the are southeast of the Ohio River through Tuesday night.
Depending on the timing of the front, the POPs on Tuesday night
might actually be a bit undone by the NBM if you believe the
ECMWF and CMC deterministic runs, but the 00z ensemble guidance
for now seems to support the lower POPs depicted. Aside from a
few stray mountain showers in upslope flow, much of the area
will see clearing on Wednesday, with dry weather area-wide on
Thursday.

After Tuesday continues the trend of lower elevation highs in
the mid to upper 70s and mountains getting into the 60s, highs
on Wednesday are forecast to be 5 to 8 degrees cooler for most
places. Temps recover on Thursday as winds shift S-SW`ly but
skies likely remain mostly clear. May need to monitor for frost
potential in the high valleys Wednesday night.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
As of 130 AM Friday...

Most sites are reporting VFR currently except for BKW, where
MVFR/IFR CIGs are prominent and will be through the period.
MVFR and IFR could also be expected at HTS and possibly EKN
through the period, but BKW will likely see the the worst
conditions through the period. Mostly VFR could be expected
elsewhere.

Bands of precipitation associated with moisture from Hurricane
Helene to our south will ripple across the area early this
morning, becoming more widespread by and after ~12z. MVFR/IFR
VIS likely within any showers/storms.

Southeast winds will strengthen through the morning peaking
between 12 and 18z. Sustained winds between 15-25kts for most,
especially the mountains with gusts between 25 and 40kts. Higher
gusts approaching 50kts are possible for elevations above 2,500
feet in elevation (i.e. BKW). Winds will gradually start
lessening in the afternoon, but may increase overnight into
Saturday morning, particularly across the southern portions of
the forecast area.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Timing and extent of low CIGs,
precipitation, and gusty winds could vary 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.

DATE               FRI 09/27/24
UTC 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
EDT 1HRLY       05   06   07   08   09   10   11   12   13   14   15   16
CRW CONSISTENCY  H    M    M    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  M    L    H    M    M    M    L    H    H    M    L    M
BKW CONSISTENCY  M    M    M    M    M    M    H    L    M    M    L    L
EKN CONSISTENCY  H    M    L    M    H    H    M    H    H    H    H    H
PKB CONSISTENCY  M    H    H    M    M    M    M    M    M    H    H    H
CKB CONSISTENCY  H    H    H    H    H    M    M    M    M    M    M    M

AFTER 06Z SATURDAY...
Brief, but repetitive periods of IFR conditions possible in
showers and storms into the weekend.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flood Watch through this evening for WVZ005-033-034-515-516-
     518-520-522>524.
     Wind Advisory until 8 PM EDT this evening for WVZ005-006-013-
     024>026-517-519-521-524-525.
     High Wind Warning until 8 PM EDT this evening for WVZ033-034-
     515-516-518-520-522-523-526.
OH...Flood Watch through this evening for OHZ087.
     Wind Advisory until 8 PM EDT this evening for OHZ083-086-087.
KY...Flood Watch through this evening for KYZ101>103-105.
     Wind Advisory until 8 PM EDT this evening for KYZ101>103-105.
VA...Flood Watch through this evening for VAZ003-004.
     High Wind Warning until 8 PM EDT this evening for VAZ003-004.

&&

$$

SYNOPSIS...FK/LTC
NEAR TERM...LTC
SHORT TERM...FK
LONG TERM...FK
AVIATION...LTC