410
FXUS61 KRLX 201526
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1126 AM 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/...
As of 1125 AM Friday...

Made minor adjustments to sky grids, allowing for widespread
clear skies, except for the northeast mountains where clouds,
showers and perhaps isolated storms may develop this afternoon.
Rest of forecast remains on track.

As of 620 AM Friday...

Freshened up temperatures and dew points this morning where a
few stations were observing slightly higher readings than
anticipated. This is most likely attributed to pockets of low
hanging clouds that hovered overnight and mitigated radiational
cooling from occurring. Otherwise, forecast remains on track
with river valley fog now spilling down into the central
lowlands this morning. This will gradually erode as the sun
continues to rise.

As of 235 AM Friday...

Surface high pressure slides slightly eastward today, but
retaining enough influence over the forecast area that will
yield mostly dry weather through the period. Early morning
microphysics satellite imagery shows river valley fog underway
along the higher terrain and is expected to spread further down
into the lowlands before dawn.

Any fog development this morning will gradually erode after
sunrise and give way to afternoon cumulus, especially along the
mountains. Additional growth along the higher terrain may foster
isolated showers and storms during peak heating hours.

Otherwise, above seasonable temperatures prevail across the
Central Appalachians today, with a few areas within the Tri-
State area and along the I-64 corridor reaching the low 90s. A
slight dip in dew points during the afternoon will bring
relative humidity values down into the 30 percent range across
the lower elevations. Light surface flow will be present
throughout the day, but dry fuels may attempt to stimulate fire
weather concerns in areas that have not received measurable
precipitation in quite some time.

A cold front marching into the Ohio Valley late tonight will
stem from a weakening disturbance north of the United States
border. Latest model runs depict a delay in showers entering the
forecast area within the valid forecast period, so opted to
trend back POPs overnight. Otherwise, another decent signal for
mountain fog seems plausible for late tonight into early
Saturday morning.

&&

.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 THURSDAY/...
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 /16Z FRIDAY THROUGH TUESDAY/...
As of 620 AM Friday...

River valley fog that spent most of the overnight only along the
mountain range has now spilled down into the central lowlands at
the time of writing. IFR/LIFR conditions continue to bounce
around at our TAF sites this morning, with the exception of BKW.
Fog will gradually erode over the next few hours and return all
sites to VFR.

For today, high pressure will yield mostly quiet weather around
Central Appalachia, but a few afternoon cumulus clouds may grow
into a shower and/or brief thunderstorm this afternoon along the
mountains. There is another decent signal for fog late tonight
into Saturday morning within the mountain valleys. Winds remain
light and variable today.

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

FORECAST CONFIDENCE: Low this morning within fog; becoming High
after daybreak.

ALTERNATE SCENARIOS: Timing of improving vsbys may vary this
morning during fog erosion.

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  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.

&&

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

&&

$$

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