090
FXUS61 KRLX 090800
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
400 AM EDT Thu Oct 9 2025

.SYNOPSIS...
A large high drifts by north of the region today through Friday.
This will lead to clear sky, with chilly nights, and frost
potential in the mountain valleys. Coastal low this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 310 AM Thursday...

GOES-R nighttime microphysics imagery evinces river valley fog
across southern portions of the area, and on up the mountains.
Issued an SPS earlier to cover this. Expect the fog to persist
through daybreak before burning off.

The frost advisory appears to be on track, as guidance suggests
low level flow diminishing early this morning with surface high
pressure ridging down the mountains.

The high will drift by to the north of the area this period,
providing dry weather with nary a cloud. Dry advection will
result in lower afternoon dew points and relative humidity
percentages compared with Wednesday, the latter in the 30s.
However, surface flow will be light.

Ridging extending south from the high, although anchored to the
mountains, will be farther east tonight compared with this
morning on account of the high moving east. This will allow for
slightly stronger low level flow, with less fog.

After the chilly start, the coldest of the season so far,
temperatures top out a bit below normal today, in the mid to
upper 60s across the lowlands and mid 50s to mid 60s in the
mountains. Tonight will eclipse this morning as the coldest of
the season so far, save perhaps for hilltops in the southern
cold fields. However, with the slightly increased low level
flow, expect only a few of the notoriously coldest mountain
valley locations to experience a freeze, and, in collaboration
with neighbors, opted to hold with the Freeze Watch in our side
of the mountains for now.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
As of 400 AM Thursday...

The surface high will continue its eastward progression, moving
off the northeast coast by Saturday. This will allow a
southerly return flow to establish and strengthen across the
region. Aloft, the upper trough will lift out, replaced by a
ridge on Friday. However, that ridge gives way to a small
mid/upper-level low dropping south through the Great Lakes on
Saturday. Meanwhile, a weak, broad southern stream short wave
trough along the southeast coast generates surface cyclogenesis
off the southeast coast Saturday.

Dry weather will continue, with a modest warming trend. Lowland
highs will return to the lower 70s for Friday, and then reach
the mid 70s for Saturday. Friday night will see a corresponding
moderation in temperatures, and the frost threat will be
significantly diminished, with lows in the northern mountain
valleys in the upper 30s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 400 AM Thursday...

The long-term period continues to feature a complex but
interesting synoptic setup. Saturday night through Sunday
night, the mid/upper-level low dropping south out of the Great
Lakes phases with the southern stream short wave trough,
resulting in rapid intensification of the coastal low that
forms Saturday, and its tracking up the east coast. By Monday, a
rather intense, stacked low pressure system may be centered
right along or just off the middle Atlantic seaboard.

While precipitation directly associated with the coast storm
may not directly impact the forecast areas, showers from the
upper-level low dropping south out of the Great Lakes are
possible across northern/eastern portions of the area Saturday
night through Sunday night.

The coastal low fills and drifts offshore Monday night through
the middle of next week, and ridging surface and aloft becomes
reestablished over the forecast area, providing dry weather,
with near seasonable and steady temperatures. A Rex block shown
to slow the coastal system down early next week in earlier
model runs is not really shown to set up now.

Later next week, models indicate another mid/upper-level low
dropping south out of eastern Canada and through the eastern
Great Lakes, re-invigorating the coastal low. While all this
happens offshore, the ECMWF has this occurring much close to
the coast, just enough to bear watching for the mountains later
next week.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
As of 215 AM Thursday...

GOES-R nighttime microphysics imagery evinces river valley fog
forming across southern portions of the area. EKN is likely to
bounce for another hour or two before settling into a more
persistent VLIFR dense fog through 12Z. Fog along the Elk River
will begin impacting CRW around 08Z, with a more persistent
VLIFR dense fog 10Z through 12Z. Elsewhere, including BKW,
expect nothing more than MVFR mist 08Z through 12Z.

The fog and mist will burn off by 14Z, with high pressure
otherwise providing VFR conditions, and nary a cumulus cloud
Thursday afternoon.

Light northeast surface flow today will veer to light east
tonight. Light north to northeast flow aloft will gradually veer
to east, southeast and then south this period.

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

FORECAST CONFIDENCE: Medium to high.

ALTERNATE SCENARIOS: Fog formation could be more widespread
than is forecast if winds go calm at more sites.

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 10/09/25
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    M    H    H    H    H
HTS CONSISTENCY  H    H    H    M    M    M    H    M    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    M    M    H    H    H
EKN CONSISTENCY  L    L    L    L    L    L    L    L    H    H    H    H
PKB CONSISTENCY  H    H    H    M    M    M    H    M    H    H    H    H
CKB CONSISTENCY  H    H    H    M    M    M    H    H    H    H    H    H

AFTER 06Z FRIDAY...
At least patchy IFR morning valley fog is possible each morning.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Frost Advisory until 9 AM EDT this morning for WVZ039-040-
     518>526.
     Freeze Watch from late tonight through Friday morning for
     WVZ523>526.
OH...None.
KY...None.
VA...None.

&&

$$

SYNOPSIS...TRM
NEAR TERM...TRM
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...TRM