304
FXUS61 KRLX 260638
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
238 AM EDT WED AUG 26 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO FORECAST THINKING.
KEY MESSAGES
1.) RIVER VALLEY FOG CLEARS SHORTLY AFTER SUNRISE THIS MORNING,
GIVING WAY TO WARM AND DRY CONDITIONS TODAY BEFORE DECAYING
SHOWERS APPROACH LATE TONIGHT.
2.) STRONG TO SEVERE THUNDERSTORMS CAPABLE OF DAMAGING WIND
GUSTS AND ISOLATED HAIL ARE POSSIBLE THURSDAY AFTERNOON AND
EVENING AHEAD OF AN APPROACHING COLD FRONT.
3.) A MOSTLY DRY SECONDARY FRONT ON FRIDAY PRECEDES BUILDING
HIGH PRESSURE, LEADING TO DRY WEATHER AND WARMING TEMPERATURES
INTO THE LOW 90S THIS WEEKEND INTO NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...
SURFACE HIGH PRESSURE POSITIONED OVERHEAD TODAY WILL MAINTAIN
QUIET AND DRY WEATHER ACROSS THE CENTRAL APPALACHIANS. SHALLOW
SURFACE INVERSIONS AND STRONG RADIATIONAL COOLING EARLY THIS
MORNING HAVE ALLOWED FOR THE FORMATION OF RIVER VALLEY. THIS
FOG WILL DISSIPATE RAPIDLY BETWEEN 7-9AM.
DAYTIME TEMPERATURES WILL CLIMB INTO THE MID 80S ACROSS THE
LOWLANDS AND 70S IN THE HIGHER TERRAIN UNDER LIGHT SOUTHERLY
FLOW, WITH RELATIVE HUMIDITY REMAINING COMFORTABLE AS DEWPOINTS
HOLD IN THE UPPER 50S TO LOWER 60S.
A PREFRONTAL TROUGH WILL APPROACH FROM THE WEST LATE TONIGHT
INTO THURSDAY MORNING. CONVECTION INITIATING OVER THE MIDWEST IS
EXPECTED TO BE IN A DECAYING STATE AS IT MOVES INTO SOUTHEAST
OHIO AND WESTERN WEST VIRGINIA NEAR DAYBREAK THURSDAY DUE TO
NOCTURNAL BOUNDARY LAYER STABILIZATION. A TIGHTENING PRESSURE
GRADIENT AND INCREASING MID-LEVEL CLOUD COVER AHEAD OF THIS
FEATURE SHOULD HELP TO LIMIT VALLEY FOG FORMATION LATE TONIGHT,
ESPECIALLY ACROSS THE MIDDLE OHIO VALLEY, THOUGH PATCHY VALLEY
FOG MAY STILL DEVELOP IN PROTECTED VALLEYS ACROSS THE SOUTHERN
COALFIELDS.
KEY MESSAGE 2...
THE PRIMARY FORECAST CHALLENGE WILL BE THURSDAY AFTERNOON AND
EVENING AS AN UPPER-LEVEL TROUGH AND ASSOCIATED SURFACE COLD
FRONT ADVANCE TOWARD THE OHIO RIVER. SOUTHERLY LOW-LEVEL FLOW
WILL DRIVE MOISTURE POOLING AHEAD OF THE BOUNDARY, WITH
DEWPOINTS RISING INTO THE UPPER 60S TO LOWER 70S. ROBUST SURFACE
HEATING WORKING INTO THIS MOIST AIRMASS WILL GENERATE MODERATE
TO STRONG INSTABILITY, WITH MIXED-LAYER CAPE RANGING FROM 1000
TO 1500J/KG BY THURSDAY AFTERNOON. DEEP-LAYER BULK SHEAR OF 20
TO 30KTS AND 0 TO 3 KM STORM-RELATIVE HELICITY OF 50 TO 100
M2/S2 WILL PROVIDE SUFFICIENT KINEMATIC SUPPORT FOR ORGANIZATION
CONVECTION.
LINEAR FORCING ALONG THE PREFRONTAL TROUGH AND FRONT WILL FAVOR
A PREDOMINANTLY MULTICELLULAR STORM MODE, THOUGH STRONG
DESTABILIZATION AND MODEST LOW LEVEL TURNING COULD SUPPORT
TRANSIENT SUPERCELL STRUCTURES. THE ATMOSPHERIC THERMODYNAMIC
PROFILE FEATURES STEEP LOW-LEVEL LAPSE RATES EXCEEDING 7.0C/KM
AND DCAPE VALUES BETWEEN 800 AND 1000J/KG. THIS ENVIRONMENT
FAVORS DAMAGING DOWNBURST WIND GUSTS AS THE PRIMARY SEVERE
THREAT. A SECONDARY THREAT OF MARGINALLY SEVERE HAIL EXISTS,
THOUGH WET-BULB ZERO HEIGHTS NEAR 11500 TO 12000 FT WILL PROMOTE
MELTING IN WEAKER UPDRAFTS; SEVERE HAIL UP TO 1 INCH IN
DIAMETER WOULD LIKELY REQUIRE STRONGER CORES, LIKELY ASSOCIATED
WITH THE AFOREMENTIONED TRANSIENT SUPERCELLULAR MODE.
CONVECTION WILL INITIALIZE ACROSS THE MIDDLE OHIO VALLEY EARLY
THURSDAY AFTERNOON, ADVANCING SOUTHEASTWARD THROUGH THE METRO
VALLEY, SOUTHERN COALFIELDS, AND CENTRAL MOUNTAINS BEFORE
DIMINISHING THURSDAY NIGHT.
KEY MESSAGE 3...
AN EAST COAST TROUGH WILL LINGER THROUGH FRIDAY, SENDING A
SECONDARY REINFORCING COLD FRONT THROUGH THE AREA. MOISTURE WILL
BE LIMITED WITH THIS BOUNDARY, KEEPING THE LOWLANDS DRY, THOUGH
TERRAIN-FORCED UPLIFT MAY SQUEEZE OUT A FEW SCATTERED SHOWERS OR
ISOLATED THUNDERSTORMS OVER THE NORTHEAST MOUNTAINS ON FRIDAY
AFTERNOON. BEHIND THIS FRONT, AN EXPANSIVE UPPER-LEVEL RIDGE
CENTERED OVER THE CENTRAL UNITED STATES WILL AMPLIFY AND SHIFT
EASTWARD INTO THE WEEKEND AND EARLY NEXT WEEK, PLACING THE
FORECAST AREA UNDER A DRY NORTHWEST FLOW REGIME. SURFACE HIGH
PRESSURE WILL SETTLE ACROSS THE CENTRAL APPALACHIANS, ENSURING
MOSTLY CLEAR SKIES AND LIGHT WINDS. DAYTIME HIGHS WILL STEADILY
MODERATE, CLIMBING BACK INTO THE LOW 90S ACROSS THE LOWLANDS BY
SUNDAY AND CONTINUING THROUGH EARLY NEXT WEEK. FORECAST GUIDANCE
MAINTAINS THE RIDGE POSITION OVER OUR REGION, KEEPING ANY RIDGE-
RIDING CONVECTIVE SHORTWAVES WELL TO OUR NORTH THROUGH AT LEAST
THE MIDDLE OF NEXT WEEK.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
SHALLOW RIVER VALLEY FOG WILL CONTINUE EXPANDING INTO EARLY
MORNING, PRODUCING LOCALIZED IFR AND LIFR VISIBILITY
RESTRICTIONS. FOG WILL DISSIPATE RAPIDLY BETWEEN 12Z AND 13Z,
YIELDING WIDESPREAD VFR CONDITIONS WITH LIGHT SOUTHERLY WINDS
UNDER 10KTS AND FAIR-WEATHER CUMULUS AROUND 4000 TO 5000 FT AGL
THROUGH THIS AFTERNOON. OVERNIGHT TONIGHT, INCREASING LOW-
LEVEL PRESSURE GRADIENTS AND MID TO HIGH CLOUD COVER APPROACHING
AHEAD OF A PREFRONTAL TROUGH WILL LIMIT FOG DEVELOPMENT ACROSS
MOST TERMINALS, THOUGH PATCHY VALLEY FOG AND MVFR VISIBILITY
REMAIN POSSIBLE IN PROTECTED SOUTHERN MOUNTAIN VALLEYS TOWARDS
DAWN THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM WITH FOG, HIGH OTHERWISE.
ALTERNATE SCENARIOS: TIMING, COVERAGE, AND INTENSITY OF FOG
MAY VARY THIS MORNING AND AGAIN TONIGHT.
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 WED 08/26/26
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 H L L M M M M H H H H H
HTS CONSISTENCY H H H M M L M H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L M M M M M M L H H H H
PKB CONSISTENCY H M L M M M M H H H H H
CKB CONSISTENCY H L L M M M L M H H H H
AFTER 06Z THURSDAY...
SCATTERED THUNDERSTORMS DEVELOPING THURSDAY AFTERNOON AND
EVENING AHEAD OF A COLD FRONT MAY BRING BRIEF IFR RESTRICTIONS
AND LOCALIZED WIND GUSTS ABOVE 30KTS TO AREA TERMINALS. PATCHY
FOG POSSIBLE FRIDAY MORNING WHERE ANY HEAVIER PRECIPITATION
FALLS THURSDAY. VALLEY FOG LIKELY THROUGH THE WEEKEND.
RLX WATCHES/WARNINGS/ADVISORIES
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
DISCUSSION...JP
AVIATION...JP
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