Area Forecast Discussion
Issued by NWS Charleston, WV

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840
FXUS61 KRLX 250809
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
409 AM EDT Thu May 25 2017

.SYNOPSIS...
Upper level low over Ohio Valley will move east across the area
bringing chances for showers and storms through Friday. Additional
disturbances bring the chance for shower and storms over the
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Thursday...

An upper low pressure system will move east from the Ohio
Valley, east across WV through tonight. This track could bring
additional rainfall to the area. In fact, high resolution and
synoptic models are in agreement on a strong vorticity max that
will sweep across the area this afternoon.

Soils across the southern half of WV are near saturated, and the
area is in a marginal risk for excessive rainfall. It will take
less rainfall to produce flooding problems. Therefore, issued a
Flash Flood Watch for counties across central and southern WV,
and extreme southwest VA through this evening.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 350 AM Thursday...

Upper level low will finally be well off to our northeast by
Friday morning. Still could see some showers across the
mountains until ridging builds in later in the day. Brief
ridging will give way to more unsettled weather for the holiday
weekend. A stationary boundary sets up from west to east across
the area and this will be the focus for showers and storms
through the weekend as several shortwave traverse the zonal
flow. Still quite a bit of uncertainty for Saturday afternoon.
Forecast soundings indicate very decent instability with
generally 1500 to 2000 J/Kg of fat CAPE with EML basically
overhead. However, it appears like there may be ongoing
convection in the morning and not sure how this will affect
convective development later in the day. Will weak short wave
impulse that will pass later in the afternoon/evening be enough
of a kicker to break the cap and kick off storms? Nonetheless,
like I have mentioned the last couple of mornings, there is a
chance for widespread severe storms Saturday afternoon with the
ingredients that will be in place.

Flash flooding also is looking like a real possibility as the
convection and already low FFG values is not what we want to see
anytime, let alone on a holiday weekend when campsites will
likely be full. For now we will just have to continue to monitor
as the forecast unfolds over the next couple days.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 350 AM Thursday...

Models continue to highlight more showers and storms on Sunday
through Monday as deep trough approaches from the west. However,
the guidance has bounced around a bit on the timing of this
feature, leading to low confidence in the forecast for days 4
through 7. Will stick with a blend of ensemble and operational
guidance for now. The main concern is definitely going to be
flash flooding, as we are really going to see our share of
rainfall leading up to the passage of this upper trough/cold
front. Will start highlighting this in the HWO as well as
possible severe storms mentioned in the short term.


&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
As of 1050 PM Wednesday...

Showers are moving north away from HTS, CRW, BKW, but affecting
CKB, EKN and PKB with IFR/MVFR conditions through a least
08-09Z.

An MVFR ceiling could stay over most sites for the rest of the
night. Conditions should improve by 13-14Z.

A low pressure system could produce numerous showers and
thunderstorms mainly this afternoon and evening. Periods of
IFR/LIFR conditions will be possible along the heavier showers.


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


Forecast Confidence: Low

ALTERNATE SCENARIOS: Post thunderstorm environments tonight may
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                              THU 05/25/17
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
HTS CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
BKW CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
EKN CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
PKB CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L
CKB CONSISTENCY  L    L    L    L    L    L    L    L    L    L    L    L

AFTER 06Z FRIDAY...
IFR possible during rainfall.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flash Flood Watch through this evening for WVZ013-015-024>027-
     033-034-515-517-519.
OH...None.
KY...None.
VA...Flash Flood Watch through this evening for VAZ003-004.

&&

$$
SYNOPSIS...ARJ/MPK
NEAR TERM...ARJ
SHORT TERM...MPK
LONG TERM...MPK
AVIATION...ARJ



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