-- Discussion containing changed information from previous version are highlighted. --
979
FXUS61 KRLX 201724
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
124 PM EDT Fri Sep 20 2024

.SYNOPSIS...
A few showers and storms may develop along the mountains this
afternoon, but otherwise mostly dry and warm under high
pressure. A weak system passes through over the weekend.

&&

.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --
As of 120 PM Friday...

Mostly dry conditions expected tonight as a surface high pressure
slides east of the Appalachians. Patchy dense fog will be
possible once again, along the most protected river valleys. Any
fog will quickly dissipate by 9 AM Saturday morning.

A weak shortwave, evident at H700, will push a cold front Saturday
morning with isolated light showers, as shown by a few of the
deterministic models. Therefore, added low PoPs for the onset of
precipitation Saturday morning across SE OH, spreading east
across WV through the afternoon. Then, aided by afternoon
heating, showers and thunderstorms should develop across the
area into the evening hours. Moderate instability with CAPE
reaching 1,800 J/kg and PWATs +2 standard deviation from the
mean suggest storms may produce localized heavy downpours. In
addition, dry air in the mid levels may allow for strong
downburst capable to produce damaging winds. SPC has most of the
area under general thunder, and a marginal risk for severe
thunderstorms across the northeast mountains for Saturday.

Tonight`s lows will range from the low to mid 60s lowlands, into the
mid 50s northeast mountains. Highs on Saturday will reach the lower
90s across the lowlands, ranging into the lower 70s northeast
mountains.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 952 AM Friday...

An upper-level ridge will briefly move over the area Sunday with the
return of dry, hot, and sunny weather areawide. Increased fire
danger will return Sunday afternoon, especially in the lowlands,
with afternoon minimum RH values expected to range from 30-40%
across the central and northern WV lowlands and portions of
southeast OH. High temperatures will reach the lower 90s across much
of the lowlands during the afternoon. Rain chances will slowly
increase from west to east Sunday night as 500-mb heights lower and
the next low pressure system approaches. The best chance of showers
Sunday night into Monday morning will be across southeast Ohio.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 952 AM Friday...

A wave of low pressure will track into the Great Lakes Monday with a
trailing cold front moving into the Ohio Valley. This will bring
more moisture into the area with afternoon minimum RH only expected
to drop to 50-60% across the WV lowlands and southeast OH. This
should mitigate the fire threat. In addition, shower chances will
return, with the greatest chances across northern WV and southeast
OH.

The rest of the week looks unsettled with chances of rain just about
each day as waves of mid-level vorticity flow along the approaching
trough. Given our drought situation, this is good news. Another
cutoff upper-level low is expected to develop by the middle of next
week, over the midwest or the Great Lakes, with not much movement
expected through the end of next week. This should bring daily
chances of showers for our region. Confidence is still low at this
time, but there is potential for some beneficial rainfall.

&&

.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 120 PM Friday...

High pressure keeps tranquil (VFR for the most part) weather
conditions tonight, before sliding east of the Appalachians
overnight. Meanwhile, patchy IFR dense fog will likely develop
along protected river valleys including EKN roughly from 06Z to
13Z. Any fog will quickly lift and dissipate by 13-14Z Saturday.

The departure of the high pressure will allow for a weak cold
front to enter SE OH around 12Z Saturday. Only a few light
showers are expected early Saturday, but afternoon heating and
available moisture will allow for additional showers and
thunderstorms development Saturday afternoon into the evening
hours. Brief periods of IFR conditions may occur along the
heavier showers or storms. Afternoon convection will gradually
weakened into the evening hours. Stronger storms may produce
strong gusty winds and heavy downpours.


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

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Timing and extend of fog 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.

UTC 1HRLY       17   18   19   20   21   22   23   00   01   02   03   04
EDT 1HRLY       13   14   15   16   17   18   19   20   21   22   23   00
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    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  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z SATURDAY...
IFR conditions possible Sunday morning along the higher terrain
from river valley fog.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...ARJ/JMC
NEAR TERM...ARJ
SHORT TERM...JMC
LONG TERM...JMC
AVIATION...ARJ