660
FXUS61 KRLX 131748
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
148 PM EDT MON JUL 13 2026
WHAT HAS CHANGED
OVERALL FORECAST THINKING REMAINS SIMILAR. DID TWEAK DOWN
AFTERNOON MIXED DEW POINTS FOR WEDNESDAY/THURSDAY BUT WILL STILL
LIKELY APPROACH HEAT ADVISORY CRITERIA.
KEY MESSAGES
1.) ISOLATED TO SCATTERED SHOWERS WILL FADE LATE THIS
AFTERNOON, GIVING WAY TO CLEARING SKIES AND THE DEVELOPMENT OF
DENSE RIVER VALLEY FOG TONIGHT.
2.) HIGH PRESSURE BRINGS A STRETCH OF HOT AND DRY WEATHER
TUESDAY THROUGH THURSDAY. HEAT INDICES WILL PEAK IN THE UPPER
90S BY WEDNESDAY AND THURSDAY AFTERNOONS.
3.) A COLD FRONT APPROACHING THIS WEEKEND WILL BRING INCREASING
CHANCES FOR THUNDERSTORMS. A FEW OF THESE STORMS COULD PRODUCE
DAMAGING WIND GUSTS OR LOCALIZED FLASH FLOODING.
DISCUSSION
KEY MESSAGE 1...
SUBTLE H850 MASS CONVERGENCE IS SUSTAINING ISOLATED TO SCATTERED
SHOWERS ACROSS THE SOUTHERN AND CENTRAL ZONES EARLY THIS
AFTERNOON. REGIONAL FORECAST SOUNDINGS INDICATE RELATIVELY WEAK
INSTABILITY, AND THIS ACTIVITY WILL REMAIN GENERALLY
DISORGANIZED AND PULSE-LIKE IN NATURE. SHOWERS WILL QUICKLY
DISSIPATE THIS EVENING WITH THE LOSS OF DAYTIME HEATING AS UPPER
LEVEL RIDGING BEGINS TO BUILD INTO THE REGION.
OVERNIGHT, CLEARING SKIES AND CALM SURFACE WINDS WILL SET THE
STAGE FOR STRONG RADIATIONAL COOLING. GIVEN THE WET ANTECEDENT
CONDITIONS IN LOCATIONS THAT SEE RAINFALL TODAY, COMBINED WITH
THE COMPLEX TOPOGRAPHY OF THE AREA, COLD AIR DRAINAGE WILL LEAD
TO THE FORMATION OF STRONG VALLEY TEMPERATURE INVERSIONS. EXPECT
DENSE FOG TO DEVELOP WITHIN THE MAJOR RIVER VALLEYS AS EARLY AS
06Z TONIGHT. THIS FOG WILL LIKELY SUPPRESS TEMPERATURE CLIMBS
INITIALLY ON TUESDAY MORNING BEFORE MIXING OUT BETWEEN 12Z AND
13Z.
KEY MESSAGE 2...
BROAD H500 RIDGING WILL EXPAND ACROSS THE EASTERN TWO-THIRDS OF
THE COUNTRY TUESDAY THROUGH THURSDAY. WIDESPREAD SUBSIDENCE
BENEATH THIS RIDGE WILL MAINTAIN DRY CONDITIONS ACROSS THE
MIDDLE OHIO VALLEY WHILE TEMPERATURES CLIMB SIGNIFICANTLY ABOVE
NORMAL. GUIDANCE INDICATES AFTERNOON HIGH TEMPERATURES WILL
COMFORTABLY REACH THE LOW TO MID 90S ACROSS THE LOWLANDS BY
WEDNESDAY.
THE NATIONAL BLEND OF MODELS EXHIBITS A PERSISTENT HIGH BIAS
REGARDING SUMMERTIME MIXED SURFACE DEW POINTS. WILL MODIFY THESE
TO REFLECT SOMETHING CLOSER TO CONSENSUS. DESPITE THIS DOWNWARD
ADJUSTMENT, AFTERNOON HEAT INDICES ARE STILL FORECAST TO REACH
THE UPPER 90S ON WEDNESDAY AND THURSDAY. LIMITED LOWLAND HEAT
ADVISORIES MAY EVENTUALLY BE REQUIRED IF CONFIDENCE INCREASES
THAT HEAT INDICES WILL TOUCH THE 100 DEGREE THRESHOLD FOR
CONSECUTIVE HOURS, BUT FOR NOW, CONDITIONS APPEAR TO REMAIN JUST
BELOW ADVISORY CRITERIA.
KEY MESSAGE 3...
BY LATE IN THE WEEK, THE UPPER LEVEL RIDGE WILL SHIFT WESTWARD,
PLACING THE FORECAST AREA WITHIN NORTHWESTERLY FLOW ALOFT.
UNCAPPED AFTERNOON SOUNDINGS MAY MATERIALIZE AS EARLY AS FRIDAY,
YIELDING ISOLATED CONVECTION, BUT A MORE ORGANIZED THREAT
ARRIVES SATURDAY AND SUNDAY AS A COLD FRONT DROPS INTO THE
REGION.
DEEP LAYER STEERING FLOW WILL INCREASE TO 20 TO 30KTS FROM THE
WEST, PROVIDING SUFFICIENT SHEAR FOR UPDRAFT ORGANIZATION
SATURDAY AND SUNDAY AFTERNOONS. MOISTURE ADVECTION AHEAD OF THE
FRONT WILL PUSH PRECIPITABLE WATER VALUES ABOVE THE 90TH
PERCENTILE OF CLIMATOLOGY. FORECAST SOUNDINGS SHOW EXTREMELY
DEEP WARM CLOUD DEPTHS, SETTING UP A HIGHLY EFFICIENT WARM RAIN
PROCESS. WHILE THE WESTERLY STEERING FLOW SUGGESTS STORMS WILL
BE PROGRESSIVE, FRONTAL CONVERGENCE COULD ORIENT CONVECTION
PARALLEL TO THE BOUNDARY, RAISING THE POTENTIAL FOR WEST TO EAST
TRAINING OF THUNDERSTORMS. IF CONFIDENCE IN THIS INCREASES, YET
ANOTHER FLASH FLOOD WATCH MAY BECOME NECESSARY.
IN ADDITION TO THE HEAVY RAIN THREAT, STEEP LOW LEVEL LAPSE
RATES WILL INCREASE THE POTENTIAL FOR DOWNDRAFTS PRODUCING TREE
DAMAGE. IN OUR HEAVILY FORESTED REGION, THE DENSE CANOPY IS
PARTICULARLY VULNERABLE DURING THE SUMMER MONTHS, AND SURFACE
GUSTS AS LOW AS 45 MPH CAN EASILY RESULT IN TREE DAMAGE.
CONFIDENCE IN THE EXACT TIMING OF THE FRONTAL PASSAGE AND THE
SUBSEQUENT END OF THE SEVERE THREAT REMAINS LOW, BUT THE OVERALL
PATTERN WARRANTS CLOSE MONITORING THROUGH THE WEEKEND.
AVIATION /18Z MONDAY THROUGH SATURDAY/
SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM REMAIN POSSIBLE
THROUGH LATE THIS AFTERNOON, PRIMARILY IMPACTING TERMINALS
ACROSS THE SOUTHERN AND CENTRAL TERRAIN INCLUDING BKW, CRW, AND
HTS. OVERALL CONFIDENCE IN A DIRECT IMPACT AT ANY GIVEN TERMINAL
IS TOO LOW TO INCLUDE ANYTHING MORE THAN VCSH FOR THE INITIAL
FORECAST PACKAGE.
ANY LINGERING PRECIPITATION WILL DISSIPATE THIS EVENING, LEAVING
BEHIND CALM WINDS AND CLEARING SKIES. THESE CONDITIONS ARE
HIGHLY FAVORABLE FOR RADIATIONAL COOLING AND THE DEVELOPMENT OF
DENSE RIVER VALLEY FOG. IFR TO LIFR VISIBILITIES AND CEILINGS
ARE EXPECTED TO DEVELOP AS EARLY AS 06Z, PARTICULARLY AT THE
TYPICALLY PRONE VALLEY TERMINALS. FOG WILL PERSIST THROUGH THE
EARLY MORNING HOURS BEFORE MIXING OUT BETWEEN 12Z AND 13Z
TUESDAY FOR THESE TERMINALS. ONCE THE INVERSION BREAKS, VFR
CONDITIONS WILL DOMINATE FOR THE REMAINDER OF THE DAY WITH LIGHT
AND VARIABLE SURFACE WINDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: HIGH THROUGH TONIGHT, THEN MEDIUM FOR FOG.
ALTERNATE SCENARIOS: FOG DEVELOPMENT MAY VARY FROM THE FORECAST
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 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
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 TUESDAY...
IFR VALLEY FOG POSSIBLE EACH MORNING THROUGH THURSDAY. IFR
POSSIBLE IN SHOWERS AND THUNDERSTORMS FOR THE WEEKEND.
RLX WATCHES/WARNINGS/ADVISORIES
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
DISCUSSION...JP
AVIATION...JP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page