839
FXUS63 KJKL 211215 AAA
AFDJKL
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
815 AM EDT FRI AUG 21 2026
KEY MESSAGES
- A SERIES OF COLD FRONTS WILL BRING A POSSIBILITY OF SHOWERS AND
THUNDERSTORMS TO THE AREA AT TIMES THROUGH SATURDAY.
- SOME STORMS ON SATURDAY AFTERNOON AND EVENING COULD PRODUCE
STRONG TO LOCALLY DAMAGING WIND GUSTS.
- NOTICEABLY COOLER AND LESS HUMID AIR WILL ARRIVE TO START THE
NEW WEEK, WITH MAINLY DRY WEATHER.
UPDATE
ISSUED AT 759 AM EDT FRI AUG 21 2026
MINOR ADJUSTMENTS WERE MADE BASED ON RADAR, SATELLITE, AND
OBSERVATIONS TRENDS TO CONVECTION NEAR THE KY BORDER WITH TN AND
VA OVER THE NEXT COUPLE OF HOURS AS WELL AS THE AREAL EXTENT AND
INTENSITY OF FOG. OVERALL, FOG SHOULD LIFT AND DISSIPATE OVER THE
NEXT 1 TO 2 HOURS AT THE LATEST. OTHERWISE, CONVECTION MAY LINGER
NEAR THE VA AND TN BORDERS OVER THE NEXT FEW HOURS THOUGH IT COULD
WANE IN COVERAGE AND INTENSITY SOMEWHAT. THEN, AS THE DAY
PROGRESSES, COVERAGE AND AREAL EXTENT SHOULD EXPAND TO THE NORTH
AND WEST, BUT GENERALLY REMAIN SOUTH OF THE MOUNTAIN PARKWAY.
SHORT TERM
(TODAY THROUGH SATURDAY)
ISSUED AT 413 AM EDT FRI AUG 21 2026
EARLY THIS MORNING, A RATHER BROAD UPPER LEVEL TROUGH EXTENDED
FROM QUEBEC ACROSS SECTIONS OF THE GREAT LAKES AND NORTHEAST TO
THE APPALACHIANS AND SOUTHEAST TO NORTHEASTERN GULF WHILE UPPER
LEVEL RIDGING WAS CENTERED IN THE FOUR CORNERS VICINITY AND
EXTENDED INTO THE PACIFIC NORTHWEST AND ALSO ACROSS THE SOUTHERN
PLAINS TO WESTERN GULF. A SHORTWAVE TROUGH MOVING THROUGH THE
TROUGH OVER THE EASTERN CONUS WAS TRAVERSING PORTIONS OF THE TN
VALLEY AND SOUTHERN APPALACHIAN REGION WHILE ANOTHER SHORTWAVE
TROUGH WAS NEARING THE WESTERN GREAT LAKES VICINITY WHILE ANOTHER
TROUGH EXTENDED FROM WESTERN SECTIONS OF HUDSON BAY INTO MANITOBA
AND SASKATCHEWAN. AT THE SURFACE, A RIDGE OF HIGH PRESSURE
EXTENDED FROM THE GREAT LAKES TO MID MS VALLEY WITH A WAVY FRONTAL
ZONE EXTENDING FROM THE MID ATLANTIC STATES INTO THE SOUTHERN
APPALACHIANS/TN VALLEY TO SOUTHERN PLAINS. CONVECTION WAS
OCCURRING IN THE VICINITY OF THIS FRONT AND THE SHORTWAVE WITH
THIS AS NEAR TO THE SOUTHERN COUNTIES AS SECTIONS OF THE EASTERN
TN INCLUDING THE CUMBERLAND PLATEAU OF TN AND CUMBERLAND MOUNTAINS
OF NE TN. CIRRUS AND MID LEVEL CLOUDS ASSOCIATED WITH THIS HAS
SPREAD INTO EASTERN KY WITH THIS MOST PREVALENT NEARER TO THE
KY/TN/V TRI STATE AREA. VALLEY FOG WAS ALSO OCCURRING WITH THIS
HAVING LESSENED IN MAGNITUDE OVER THE FAR SOUTH AND THIS REMAINED
DENSE MAINLY NORTH OF THE HAL ROGERS PKWY/KY 80 CORRIDOR AND IN
THE BIG SANDY REGION AROUND AND EAST OF THE US 23 CORRIDOR.
TODAY AND TONIGHT, GUIDANCE TAKES THE INITIAL SHORTWAVE IN THE
EASTERN TN VALLEY AND SOUTHERN APPALACHIANS EAST NORTHEAST THIS
MORNING AND TO THE SOUTH AND SOUTHEAST OF EASTERN KY BY THIS
AFTERNOON WHILE THE NEXT SHORTWAVE MOVING THROUGH THE MEAN TROUGH
EXTENDING INTO THE EASTERN CONUS MOVES INTO THE GREAT LAKES TO
LOWER OH VALLEY REGION. THE SFC WAVE IS PROGGED TO TRACK INTO OR
NEAR SOUTHEASTERN KY WITH THE BOUNDARY LIFTING TOWARD OR INTO
SOUTHERN SECTIONS OF THE AREA THIS MORNING TO EARLY AFTERNOON
BEFORE SETTLING BACK TO THE SOUTH AND SOUTHEAST LATER THIS
AFTERNOON AND EVENING. FOG SHOULD GRADUALLY LIFT WITHIN 2 TO 3
HOURS OF SUNRISE ACROSS THE NORTH AND EAST TODAY WITH MARGINAL/WEAK
INSTABILITY DURING PEAK HEATING THERE AND MODERATE INSTABILITY,
1000 TO 1500+ J/KG MLCAPE PER RECENT RAP RUNS NEARER TO THE TN AND
VA BORDERS. THIS WILL SUPPORT SOME CONVECTION GENERALLY SOUTH OF
THE MTN PARKWAY TODAY, PARTICULARLY NEARER TO THE VA AND TN BORDER
AND THE FRONTAL BOUNDARY/BAROCLINIC ZONE. WITH THE LOSS OF
DAYTIME HEATING CONVECTION SHOULD WANE AROUND OR NOT LONG AFTER
SUNSET THIS EVENING. ANOTHER ROUND OF MAINLY VALLEY FOG SHOULD BE
FAVORED TO DEVELOP AROUND OR SHORTLY AFTER MIDNIGHT ALONG THE
RIVERS, LAKES, AND LARGER CREEKS AND NEAR WHERE RAIN IS MORE
PREVALENT LATER TODAY.
FOR SATURDAY, AN INITIAL SHORTWAVE SHOULD MOVE EAST OF THE AREA
DURING THE MORNING TO MIDDAY, HOWEVER, A MORE POTENT SHORTWAVE
SHOULD DRIFT INTO THE WESTERN TO CENTRAL GREAT LAKES TO LOWER OH
VALLEY AS THE DAY PROGRESSES. THIS WILL BE PRECEDED BY AN AREA OF
LOW PRESSURE THAT TRACKS ACROSS MI AND INTO ONTARIO AND A COLD
FRONT THAT DROPS TO NEAR THE OH RIVER BY EVENING. WITH TEMPERATURES
PEAKING IN THE LOW TO MID 80S WITH AT LEAST MID 60S DEWPOINTS,
MODERATE INSTABILITY SHOULD DEVELOP ACROSS EASTERN KY BY LATE
SATURDAY AFTERNOON AND EVENING WITH 03Z RAP FORECASTING ROUGHLY
1000 TO 2000 J/KG OF MLCAPE WITH AT LEAST 20 TO 25KT OF BULK SHEAR
SUFFICIENT FOR SOME POTENTIAL MULTICELL CLUSTERS OR LINE SEGMENTS
AND STEEP LOW LEVEL LAPSE RATES.
CONVECTIVE ALLOWING MODELS HAVE VARYING AMOUNTS OF COVERAGE OF
CONVECTION FOR THE SATURDAY AFTERNOON TO EARLY EVENING TIMEFRAME
WITH THE 06Z HRRR HAVING LESS COVERAGE AS COMPARED TO THE 00Z HRRR
RUN. HOWEVER, BOTH OF THE LAST TWO HRRR RUNS HAVE RATHER STRONG
WIND GUSTS WITH WHAT COVERAGE THEY FORECAST AND ARE INDICATIVE OF
AT LEAST A CONDITIONAL THREAT FOR STRONG TO DAMAGING WIND GUSTS
WITH WHAT MANAGES TO DEVELOP AHEAD OF THE COLD FRONT AND SHORTWAVE
DURING PEAK HEATING SATURDAY. FOR NOW, HAVE OPTED TO INCLUDE THE
POTENTIAL FOR STRONG TO DAMAGING WIND GUSTS IN THE KEY MESSAGES
ABOVE AS WELL AS IN THE HWO AND SOCIAL MEDIA/WEATHERSTORY POSTS.
LONG TERM
(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 AM EDT FRI AUG 21 2026
THE LONG TERM PERIOD WILL OPEN WITH DEEP UPPER LEVEL TROUGHING OVER
THE EASTERN CONUS AND A HIGH AMPLITUDE UPPER LEVEL RIDGE CENTERED
NEAR THE FOUR CORNERS REGION. AT THE SURFACE, CONVECTION WILL BE
EXITING FAR EASTERN KENTUCKY AS THE PREVIOUS SYSTEM DEPARTS.
MEANWHILE, A SURFACE LOW WILL BE LOCATED OVER THE GREAT LAKES,
WITH AN ADDITIONAL COLD FRONT DRAPED TO THE SOUTHWEST. AS THIS LOW
LIFTS NORTHEASTWARD, ITS ASSOCIATED FRONT WILL PROGRESS EASTWARD
INTO THE FORECAST AREA ON SUNDAY. UNLIKE THE PREVIOUS SYSTEM, THE
FRONTAL PASSAGE IS EXPECTED TO REMAIN DRY, OWING TO LIMITED
MOISTURE AHEAD OF THE FRONT. THE MAIN IMPACT WILL BE COOLER AND
DRIER WEATHER BEHIND THIS BOUNDARY; DEWPOINTS WILL FALL INTO THE
50S, AND HIGH TEMPERATURES WILL STRUGGLE TO REACH BEYOND THE UPPER
70S TO LOW 80S ON SUNDAY AFTERNOON. OVERNIGHT, CLEAR SKIES AND A
WEAK PRESSURE GRADIENT WILL ALLOW A MODEST RIDGE/VALLEY
TEMPERATURE SPLIT TO DEVELOP. MOS GUIDANCE COULD BE SLIGHTLY
AGGRESSIVE WITH THIS COOLING FOR A FEW SPOTS, BUT GIVEN THE RATHER
DRY AIRMASS (PW BELOW THE 20TH PERCENTILE PER LREF) SHOULD ALLOW
FOR RATHER IDEAL RADIATIONAL COOLING CONDITIONS, IT SEEMS
PLAUSIBLE THAT LOW TEMPERATURES COULD FALL INTO THE MID 50S FOR
VALLEY LOCATIONS, WITH TYPICAL FOG FORMATION.
FORECAST UNCERTAINTY INCREASES ON MONDAY AND TUESDAY AS EASTERN
KENTUCKY FINDS ITSELF ON THE WESTERN FRINGES OF THE PROGRESSING
TROUGH. WITHIN INCREASINGLY NORTHWESTERLY FLOW ALOFT, SOME MODEL
GUIDANCE SUGGESTS SHORTWAVE ENERGY COULD SPARK ADDITIONAL RAIN CHANCES
AS EARLY AS MONDAY AFTERNOON, ALTHOUGH ENSEMBLES STILL FAVOR AN
ANOMALOUSLY DRY ENVIRONMENT THROUGH TUESDAY OVERALL. GIVEN LIMITED
AGREEMENT IN THE EVOLUTION OF THESE SMALLER SCALE IMPULSES, POPS
REMAIN LOW, WITH THE EXCEPTION OF THE SOUTHERN PORTION OF THE
FORECAST AREA WHERE A SLIGHT CHANCE OF SHOWERS AND STORMS WAS
INTRODUCED. ALTHOUGH THIS HIGHLIGHTS A MARGINALLY HIGHER CONSENSUS
REGARDING MODEST RAIN CHANCES, FORECAST CONFIDENCE IS STILL LOW,
AND ANY COVERAGE DETAILS WILL BEAR REFINING IN THE COMING DAYS.
BARRING CONVECTIVE INTERFERENCE, HIGHS SHOULD STILL REMAIN IN THE
UPPER 70S TO LOW 80S ON MONDAY AFTERNOON, WITH LOW TEMPERATURES IN
THE MID TO UPPER 50S ACROSS THE FORECAST AREA OVERNIGHT. ON
TUESDAY, THE EASTWARD EXPANSION OF THE UPPER LEVEL RIDGE WILL
ALLOW TEMPERATURES TO CLIMB A FEW DEGREES, WITH HIGHS RANGING FROM
THE LOW TO MID 80S.
MORE ROBUST RAIN CHANCES WILL RETURN BY MIDWEEK AS A CLOSED UPPER
LEVEL LOW PROGRESSES TO THE SOUTHEAST FROM MANITOBA INTO THE UPPER
MIDWEST. IN TURN, DEEPENING UPPER LEVEL TROUGHING OVER THE MIDWEST
WILL LEAD TO BROAD HEIGHT FALLS ACROSS THE OHIO VALLEY, WITH
SOUTHWESTERLY TO WESTERLY SURFACE WINDS ALLOWING DEWPOINTS TO RISE
BACK INTO THE UPPER 60S AND LOW 70S. THIS, IN COMBINATION WITH THE
POTENTIAL FOR ADDITIONAL SHORTWAVE ACTIVITY, WILL MAINTAIN POPS IN
THE NEIGHBORHOOD OF 30-40% ON BOTH WEDNESDAY AND THURSDAY.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 810 AM EDT FRI AUG 21 2026
FOG LINGERS IN VALLEYS GENERALLY NORTH OF A KSME TO KLOZ TO KPBX
LINE WITH REDUCTIONS AT MAINLY NON TAF SITE LOCATIONS TO AS LOW
AS VLIFR. KSJS HAD OBSERVED VLIFR/BELOW AIRPORT INITIALLY. ALL
LOCATIONS EXPERIENCING FOG SHOULD EXPERIENCE IT LIFTING AND
DISSIPATING THROUGH 13Z OR 14Z. OTHERWISE, NEAR THE VA AND TN
BORDERS, A PASSING DISTURBANCE IS INTERACTING WITH A FRONTAL ZONE
FOR A BIT OF CONVECTION. THIS MAY EXPAND A BIT IN COVERAGE NORTH
AND WEST GENERALLY AFTER 15Z OR 16Z AND LINGER AS LATE AS 23Z AND
AFFECT LOCATIONS NEAR OR JUST TO THE SOUTH OF A LINE FROM KSME TO
KJKL TO KSJS. THEREAFTER, VALLEY FOG SHOULD AGAIN DEVELOP AND
THIS MAY AFFECT A FEW OF THE TAF SITES DURING THE 06Z TO 12Z. AS
FOR WINDS, OUTSIDE OF ANY STORMS, WINDS WILL GENERALLY BE LIGHT
AND VARIABLE.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...JP
SHORT TERM...JP
LONG TERM...FAGAN
AVIATION...JP
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