703
FXUS61 KRLX 261805
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
205 PM EDT Thu Sep 26 2024

.SYNOPSIS...
Periods of rain will continue tonight. Remnants of Helene arrive
Friday morning, spreading strong gusty winds and additional
rainfall into the weekend.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 202 PM Thursday...

Key Points:

 * Flash Flood Watch in effect until 7 PM Friday for southwest
   VA, and along the WV eastern mountains.

 * High Wind Warning in effect until 7 PM Friday for Dickenson
   and Buchanan in VA, and McDowell in WV.

 * Wind Advisory in effect until 7 PM Friday from Wyoming, north
   through the higher elevations of Pocahontas and Randolph
   counties.

Deepening upper level low pressure will continue to bring abundant
moisture and precipitation mainly across the southern half of
the area tonight. Meanwhile, the center of T.S. Helene will
approach from the south into central KY. Remnants of Helene
(precipitation and strong winds) will be arrive to our area
early Friday, bringing additional precipitation and non-
thunderstorm high/strong winds.

Radar rainfall estimates and rain gauges show from 2 to 4
inches of rain have fallen during the last 24 hours, wetting the
local terrain across the eastern mountains. Additional 1 to 2
inches can be expected over these areas through Friday evening.
This will continue to produce additional water rises of nearby
rivers and creeks, and flooding issues of low lying areas,
flood prone areas or even smaller creeks coming out of their
banks. Therefore, a Flash Flood watch was issued.

Remnants of Helene will be arrive to our area early Friday,
bringing additional precipitation and non-thunderstorm
high/strong winds. Dynamic ensemble model solutions suggest
strong winds 15 to 20 knots arriving to our eastern mountains
early Friday. There is high confidence for wind gusts exceeding
50 knots across our southern mountains, and up to 45 knots
across the higher elevations of our central and northern
mountains on Friday. Therefore, a High Wind Warning was issued
for Buchanan, Dickenson and McDowell through Friday evening. For
the same token, a Wind advisory was issued for the rest of the
higher elevations north to Pocahontas and Randolph.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 430 AM Thursday...

Key Points

 * The remnants of Hurricane Helene, coupled with a stationary
   system over the Ohio Valley, will promote periods of heavy
   rain on Friday and into this weekend.

 * An additional half an inch to an inch of rainfall is possible
   through Saturday.

 * A tightened pressure gradient inflicted by this system may
   yield strong wind gusts along the higher terrain Friday
   morning into the early afternoon.

After Hurricane Helene makes landfall Thursday evening, the
system will march northward through the Mississippi Valley and
congeal with the stationary upper level low positioned just west
of the forecast area. This transformation will continue to
usher in a plethora of moisture up into Central Appalachia and
maintaining active weather for Friday and into the start of the
weekend.

A resultant tightening pressure gradient from this stacked
disturbance will impose strengthening winds in the low to mid
levels, especially along the mountain range. One of the many
challenging pieces with this forecast will be whether this
strong winds aloft can be pulled down to the surface. Forecast
soundings depict a predominantly moist profile, which could keep
these stronger winds capped above, but could also be dragged to
the surface with showers and potentially strong thunderstorms.
The motion of Helene as the storm lifts over land will also
dictate wind uncertainty as it takes a sharp western turn and
becomes absorbed with a baroclinic system over the Tennessee
Valley. Forecast offices to the south have already hoisted a
High Wind Watch for their mountain range on Friday, but with
some uncertainty still prevalent with gust potential, will hold
off on jumping on headlines with this issuance.

In regards to rainfall, the best opportunity for higher QPF
amounts will occur Friday morning into the afternoon as Helene
takes the aforementioned western trajectory across the southern
Appalachians into the the middle Ohio Valley. An additional inch
of rain could be achieved during this time through the Tug Fork
river basin and up into the Ohio River Valley. Localized
flooding is still feasible, but the higher flash flooding threat
remains progged to be south of the forecast area down into the
Tennessee Valley and Carolinas.

At the start of the weekend, the tail end of precipitation
associated with a nearby frontal boundary will detach from the
Ohio Valley upper level low. The forecast area enters into a
rain shadow period, where lessening POPs overtake the area as
the low deepens southward and pivots showers further away to the
west, and the eastern flank of moisture pushes offshore.
However, this should be short-lived on Saturday as rejuvenated
moisture wraps around the stacked upper level low and the system
slowly drifts back to the east.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 430 AM Thursday...

The second half of the weekend features the strong upper level
disturbance becoming an open wave and slowly shifting into the
Central Appalachians. Rain bands circulating the center of the
system will become less impressive as the long term period
marches on, but still could produce chance to likely (50-75%)
POPs. This trend will hold through the first half of the work
week as the open 500mb wave and the remnants of the surface low
continues to pivot over the Mid-Atlantic region.

The last batch of rain departs the forecast area late Wednesday
night into Thursday, with the forecast becoming dry under
establishing high pressure. Temperatures will be around
seasonable for this time of year throughout the period, with
afternoon highs ranging in the 60s along the higher terrain and
mid to upper 70s across the lowlands.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
As of 145 PM Thursday...

MVFR/IFR conditions, under periods of mostly stratiformed rain,
will continue across BKW, CRW and HTS through tonight. VFR/MVFR
conditions are anticipated across PKB, CKB and EKN through this
evening where less rain is expected. Then, conditions may
deteriorate as persistent precipitation blankets the southern
half of the area later tonight. There may be a lull in
precipitation overnight, but ceilings will remain IFR or worse
into the early Friday morning.

Remnants of Helene will bring strong winds aloft in the order
of 50 to 60 knots. These winds will produce strong gusty winds,
higher at higher elevations peaking around 15Z Friday,
gradually subsiding into Friday evening. Therefore, coded LLWS
at BKW, CRW, HTS, and EKN from 15Z on despite having surface
gusty winds.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...

FORECAST CONFIDENCE: Medium to high.

ALTERNATE SCENARIOS: Timing and extent of low CIGs will vary
somewhat from the 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       15   16   17   18   19   20   21   22   23   00   01   02
EDT 1HRLY       11   12   13   14   15   16   17   18   19   20   21   22
CRW CONSISTENCY  L    H    H    M    M    M    M    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    M    M    M    M    H    H
BKW CONSISTENCY  H    H    H    M    M    M    H    H    H    H    H    H
EKN CONSISTENCY  L    L    L    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  L    L    L    H    H    H    H    H    H    H    H    H

AFTER 18Z FRIDAY...
Brief, but repetitive periods of IFR conditions possible in
showers and storms throughout the week and into the weekend.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flood Watch through Friday evening for WVZ033-034-515-516-518-
     520-522>524.
     High Wind Warning until 8 PM EDT Friday for WVZ033.
     Wind Advisory until 8 PM EDT Friday for WVZ034-515-516-518-520-
     522-523-526.
OH...None.
KY...None.
VA...Flood Watch through Friday evening for VAZ003-004.
     High Wind Warning until 8 PM EDT Friday for VAZ003-004.

&&

$$

SYNOPSIS...MEK/JZ
NEAR TERM...ARJ
SHORT TERM...MEK
LONG TERM...MEK
AVIATION...ARJ