349
FXUS61 KRLX 071811
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
211 PM EDT WED OCT 7 2026
WHAT HAS CHANGED
DEWPOINTS WERE LOWERED SLIGHTLY FOR THIS AFTERNOON AND MORE
SUBSTANTIALLY FOR THURSDAY AND FRIDAY AFTERNOONS. RAIN FROM THE
REMNANTS OF ISAIAS IS NOW TIMED AS EARLY AS LATE SATURDAY
AFTERNOON THROUGH LATE SUNDAY NIGHT.
KEY MESSAGES
1.) DRY AND UNSEASONABLY MILD WEATHER HOLDS THROUGH SATURDAY
MORNING.
2.) REMNANT MOISTURE FROM ISAIAS IS EXPECTED TO BRING A SOAKING
RAIN FROM AS EARLY AS LATE SATURDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
3.) HIGH PRESSURE RETURNS BRIEFLY EARLY NEXT WEEK, FOLLOWED BY
A WEAK COLD FRONT TUESDAY NIGHT.
DISCUSSION
KEY MESSAGE 1...
HIGH PRESSURE REMAINS THE MAIN SURFACE FEATURE THROUGH THE START
OF THE WEEKEND, AND THE FORECAST AREA IS CLEAR AND MILD THIS
AFTERNOON. AFTERNOON HIGHS SHOULD REACH THE UPPER 70S TO
AROUND 80 IN THE METRO VALLEY, SOUTHEAST OHIO, AND NORTHEAST
KENTUCKY, AND THE MID 60S TO LOWER 70S ON THE HIGHER RIDGES OF
THE NORTHEAST MOUNTAINS. A DRY LAYER IS ALREADY PRESENT JUST
ABOVE THE BOUNDARY LAYER. MIXING INTO THAT LAYER SHOULD PULL
AFTERNOON DEWPOINTS DOWN INTO THE 40S TO AROUND 50 BY LATE DAY,
SEVERAL DEGREES BELOW CENTRAL GUIDANCE, WHICH HOLDS THE MID
50S. MINIMUM RELATIVE HUMIDITY THIS AFTERNOON SHOULD FALL INTO
THE 30 TO 45 PERCENT RANGE IN THE LOWLANDS. THAT IS DRY FOR
EARLY OCTOBER, BUT WIND IS TOO LIGHT AND THE FOREST FLOOR
REMAINS GENERALLY SHELTERED BY TREES IN NEARLY FULL LEAF FOR
MUCH OF A FIRE WEATHER CONCERN. YESTERDAY AFTERNOON 10 HOUR
FUEL MOISTURE AT SEVERAL RAWS SITES FELL TO AROUND 7 TO 11
PERCENT, THEN RECOVERED ABOVE 18 PERCENT OVERNIGHT WITH NO
RAINFALL, SO FINE DEAD FUELS ARE DRYING EACH AFTERNOON AND
RECOVERING AT NIGHT.
A DRY COLD FRONT CROSSES FROM NORTHWEST TO SOUTHEAST LATE
TONIGHT INTO THURSDAY MORNING. PARENT LOW PRESSURE STAYS WELL
NORTH, OVER JAMES BAY AND QUEBEC, AND THE BOUNDARY HAS
ESSENTIALLY NO MOISTURE WITH IT. THE SENSIBLE CHANGE IS THE
WIND SHIFT TO NORTHWEST AND A DEEPER PUSH OF DRY AIR.
THURSDAY AND FRIDAY AFTERNOONS LOOK SEVERAL DEGREES DRIER THAN
RAW CENTRAL GUIDANCE DEWPOINTS. MOS CONSENSUS DROPS CHARLESTON
DEWPOINTS INTO THE UPPER 30S TO MID 40S BEHIND THE FRONT, AND
HRRR ALREADY MIXES HUNTINGTON AND THE NORTHEAST KENTUCKY SITES
INTO THE UPPER 30S TO AROUND 40 BY LATE THIS AFTERNOON.
AFTERNOON HIGHS THURSDAY SHOULD STILL REACH THE UPPER 70S TO
AROUND 80 IN THE LOWLANDS AND THE UPPER 60S TO MID 70S IN THE
HIGHER TERRAIN, THEN THE MID TO UPPER 70S FRIDAY, WITH MINIMUM
RELATIVE HUMIDITY AGAIN NEAR 30 TO 40 PERCENT. NORTHWEST WIND
THURSDAY AFTERNOON WILL BE 10 TO 15 MPH, WITH GUSTS 20 TO 30 MPH
ON THE MORE EXPOSED RIDGES OF THE NORTHEAST MOUNTAINS.
FRIDAY MORNING SHOULD BE THE CHILLIEST OF THIS STRETCH OF THE
FORECAST, AND CENTRAL GUIDANCE LOOKS TOO WARM IN THE VALLEYS AS
IS TYPICAL IN THESE SETUPS. THE FORECAST LEANS TOWARD THE
COOLER MOS SOLUTION IN AREAS SUBJECT TO COLD AIR DRAINAGE AWAY
FROM MAJOR RIVERS: MID 30S TO AROUND 40 IN THE SHELTERED
MOUNTAIN VALLEYS, AND THE MID 40S IN THE METRO VALLEY AND ALONG
THE MAJOR RIVERS. WHERE THE TEMPERATURE AND DEWPOINT BOTH SETTLE
IN THE MID 30S UNDER A CLEAR SKY AND CALM WIND, PATCHY FROST IS
POSSIBLE FRIDAY MORNING, MAINLY IN THE NORTHEAST MOUNTAINS AND
COLDER HOLLOWS. RIDGETOPS WILL STAY MILDER THAN THE VALLEYS. A
SIMILAR, SLIGHTLY LESS COLD RIDGE/VALLEY SPLIT IS POSSIBLE
SATURDAY MORNING BEFORE CLOUDS THICKEN.
KEY MESSAGE 2...
TROPICAL STORM ISAIAS WAS CENTERED JUST NORTH OF THE BAY OF
CAMPECHE MOVING EAST-NORTHEAST AT 7KTS, WITH MAXIMUM SUSTAINED
WIND OF 40KTS AND A CENTRAL PRESSURE NEAR 1000 MB AS OF THE 10AM
NHC FORECAST. THE OFFICIAL FORECAST TAKES IT TO HURRICANE
STRENGTH ON THURSDAY, TOWARD THE NORTHERN GULF COAST ON FRIDAY,
INLAND AS A WEAKENING TROPICAL STORM SATURDAY MORNING, AND TO A
DEPRESSION NEAR THE LOWER OHIO VALLEY BY EARLY SUNDAY.
THE LIKELY LOCAL OUTCOME IS A SURGE OF TROPICAL MOISTURE
BEGINNING AS EARLY AS SATURDAY AFTERNOON, FIRST IN THE SOUTHERN
COALFIELDS AND NORTHEAST KENTUCKY, THEN SPREADING ACROSS THE
REST OF THE AREA SATURDAY NIGHT. RAIN SHOULD PERSIST THROUGH AT
LEAST LATE SUNDAY NIGHT AS THAT MOISTURE INTERACTS WITH AN
APPROACHING MID-LATITUDE TROUGH. A GENERAL 1 TO 2 INCHES IS
EXPECTED WITH THE 48 HR TOTAL INTERQUARTILE RANGE AROUND THOSE
VALUES. A FARTHER EAST OR FASTER REMNANT WOULD FAVOR THAT LOWER
END AND WOULD KEEP THE BETTER LOW-LEVEL SHEAR EAST OF THE
FORECAST AREA. A SLOWER OR FARTHER WEST TRACK WOULD HOLD THE
CIRCULATION OVER THE OHIO VALLEY LONGER ON SUNDAY AND COULD PUSH
LOCAL TOTALS ABOVE 2 INCHES, ESPECIALLY IF HEAVIER CORES TRAIN.
THE MOST EFFICIENT RAIN LOOKS TO BE LATE SUNDAY MORNING INTO
SUNDAY AFTERNOON. FORECAST PROFILES AT CHARLESTON AND BECKLEY
FOR SUNDAY MORNING ARE NEARLY SATURATED FROM THE SURFACE THROUGH
H700, WITH THE FREEZING LEVEL AND WET-BULB ZERO BOTH NEAR 12000
TO 14000 FT. THAT IS A DEEP WARM-CLOUD LAYER. BUOYANCY LOOKS
TALL BUT SKINNY, EXTENDING UP TOWARD H400, WHICH FAVORS
EFFICIENT WARM-RAIN PROCESSES.
ISOLATED POOR-DRAINAGE FLOODING AND QUICK RISES ON SMALL
STREAMS ARE POSSIBLE IF A HEAVIER BAND STALLS. SOUTHEAST FLOW
AHEAD OF THE REMNANT LOW CAN ALSO WRING OUT A BIT MORE ON
WINDWARD EASTERN SLOPES AND, BY ISENTROPIC DESCENT, LOCALLY CUT
TOTALS ON THE IMMEDIATE LEE SIDE OF THE HIGHER RIDGES. RAIN
TAPERS FROM WEST TO EAST SUNDAY NIGHT INTO MONDAY AS THE
REMNANT LOW PULLS TOWARD THE ATLANTIC.
SEVERE WEATHER CHANCES LOOK LOW, BUT THEY ARE NOT ZERO ON
SUNDAY. INSTABILITY SHOULD BE LARGELY ELEVATED, WHICH KEEPS THE
TORNADO THREAT LIMITED. IF PARCELS CAN BECOME SURFACE BASED
DURING THE DAY NEAR THE CORE OF THE REMNANT EXTRATROPICAL LOW,
LOW-LEVEL TURNING ON THE EAST SIDE OF THAT CIRCULATION COULD
SUPPORT A COUPLE OF TORNADOES. A FARTHER-EAST TRACK WOULD LEAVE
THE FORECAST AREA IN ELEVATED RAIN WITH LITTLE POTENTIAL FOR ANY
SURFACE BASED INSTABILITY.
THE STRONGEST NON-CONVECTIVE WINDS WITH THIS SYSTEM SHOULD COME
LATE SATURDAY NIGHT INTO SUNDAY MORNING IN DOWNSLOPE OFF OF THE
HIGHER TERRAIN IN SOUTHEAST FLOW WHERE GUSTS OF 20 TO 35 MPH ARE
POSSIBLE.
KEY MESSAGE 3...
HIGH PRESSURE BUILDS BACK IN FOR MONDAY AND TUESDAY, WITH A
RETURN TO DRY WEATHER AND SEASONABLE TEMPERATURES. ANOTHER WEAK
COLD FRONT IS EXPECTED TUESDAY NIGHT IN NORTHWEST FLOW ALOFT.
MOISTURE WITH THAT BOUNDARY LOOKS LIMITED, SO THE MAIN IMPACT
SHOULD BE A WIND SHIFT AND A COOLER WEDNESDAY RATHER THAN
ANOTHER SOAKING.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
VFR CONDITIONS CONTINUE THROUGH THIS EVENING AT ALL SITES.
SOUTHWEST TO WEST WIND OF 5 TO 10KTS, WITH A FEW GUSTS NEAR
15KTS DIMINISH AFTER SUNSET.
SOME PATCHY VALLEY FOG IS POSSIBLE AFTER 06Z, BUT WEAK SOUTH TO
SOUTHWEST FLOW AHEAD OF THE DRY COLD FRONT SHOULD GENERALLY KEEP
THE TERMINALS VFR. EKN IS THE NOTABLE EXCEPTION, WHERE A
SHELTERED VALLEY AND A LIGHTER WIND COULD ALLOW MVFR TO IFR
VISIBILITY FOR A FEW HOURS LATE TONIGHT INTO THURSDAY MORNING.
MID AND HIGH CLOUDS ARE NOT EXPECTED TO BE THICK ENOUGH TO
FULLY SHUT DOWN RADIATIONAL COOLING, BUT THE BOUNDARY-LAYER WIND
SHOULD BE ENOUGH TO LARGELY LIMIT DENSE FOG FROM GETTING UP
ONTO THE RIDGETOP TERMINALS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: HIGH, EXCEPT MEDIUM FOR FOG FORMATION
OVERNIGHT.
ALTERNATE SCENARIOS: VALLEY FOG COULD QUICKLY DEVELOP AS WINDS
GO CALM IN THE PRE FRONTAL WIND SHIFT OVERNIGHT.
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 THURSDAY...
VALLEY FOG LIKELY FRIDAY AND POSSIBLY SATURDAY MORNING. IFR
POSSIBLE IN RAIN SATURDAY NIGHT THROUGH SUNDAY NIGHT.
RLX WATCHES/WARNINGS/ADVISORIES
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
DISCUSSION...JP
AVIATION...JP
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