138
FXUS63 KJKL 071958
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
358 PM EDT WED MAY 7 2025
KEY MESSAGES
- THE PERIODIC POTENTIAL FOR SHOWERS AND THUNDERSTORMS CONTINUE
INTO NEXT WEEK, WITH CHANCES PEAKING THURSDAY AFTERNOON AND
MONDAY INTO TUESDAY.
- SOME OF THUNDERSTORMS ON THURSDAY AFTERNOON AND EVENING, MAINLY
SOUTH OF THE MTN PKWY, COULD BE STRONG TO SEVERE WITH GUSTY TO
DAMAGING WIND GUSTS, HAIL, AND HEAVY RAIN POSSIBLE.
- TEMPERATURES WILL AVERAGE NEAR NORMAL INTO THE UPCOMING
WEEKEND.
SHORT TERM
(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 350 PM EDT WED MAY 7 2025
AS OF MID AFTERNOON, AN UPPER LEVEL RIDGE EXTENDED FROM THE
SOUTHWESTERN GULF OF MEXICO TO THE BAHAMAS. A CLOSED LOW OVER THE
NORTHEAST/ST LAWRENCE VALLEY CONTINUES TO GRADUALLY DEPART FURTHER
TO THE NORTH AND EAST, WHILE THERE IS ANOTHER CLOSED LOW IN
PORTIONS OF THE PLAINS/CENTRAL CONUS WITH UPPER RIDGING EXTENDING
FROM THE EASTERN PACIFIC TO PORTIONS OF THE ROCKIES TO NORTHERN
PLAINS. A 500 MB TROUGH EXTENDS FROM PORTIONS OF QUEBEC TO THE
GREAT LAKES. SHORTWAVE UPPER LEVEL RIDGING CONTINUES TO SHIFT
NORTHEAST OF THE COMMONWEALTH, WHILE A SHORTWAVE TROUGH WAS
WORKING ACROSS PORTIONS OF THE OH VALLEY TO SOUTHERN APPALACHIANS.
ADDITIONAL DISTURBANCES/SHORTWAVES WERE UPSTREAM IN SOUTHWEST
FLOW WITH ONE EXTENDING FROM THE UPPER LOW ACROSS AR TO THE LOWER
MS VALLEY. MOISTURE CONTINUES TO INCREASE FROM THE SOUTH AND
SOUTHWEST AS THE RIDGING DEPARTS WITH PW RECENTLY ANALYZED FROM
NEAR 0.7 INCHES IN FAR SOUTHEASTERN KY TO NEAR 1.1 INCHES NEAR THE
TN BORDER. A MOISTURE GRADIENT AND SOME DENSER CLOUDS ARE PRESENT
ACROSS THE SOUTHERN PORTIONS OF THE CWA AT PRESENT WITH LIGHT
SHOWERS AND SPRINKLES OCCURRING WITH IT.
THIS EVENING INTO THURSDAY, THE UPPER LEVEL LOW IN THE CENTRAL
CONUS IS EXPECTED TO GRADUALLY OPEN UP AND INTERACT WITH THE
TROUGH OVER CANADA AS IT PROGRESS TO THE EAST AND TO THE CENTRAL
AND EASTERN GREAT LAKES. THE AXIS OF UPPER LEVEL TROUGHING SHOULD
STILL REMAIN FROM THE ST LAWRENCE VALLEY TO THE OH VALLEY TO
PORTIONS OF THE SOUTHERN PLAINS AT THE END OF THE PERIOD LATE
THURSDAY NIGHT. A COLD FRONT IN ADVANCE OF THE UPPER TROUGHING IS
EXPECTED TO MOVE INTO THE NORTHEAST CONUS TO MID ATLANTIC TO MID
MS VALLEY BY LATE TONIGHT AND THEN SOUTHEAST AND INTO EASTERN KY
ON THURSDAY AFTERNOON AND THEN SOUTHEAST OF EASTERN KY ON THURSDAY
NIGHT.
THIS EVENING AND TONIGHT, MOISTURE WILL CONTINUE TO INCREASE AND
WITH A LEAD SHORTWAVE OR TWO CROSSING THE AREA, CONVECTION WILL
REMAIN POSSIBLE AT TIMES. PW PER THE 12Z HREF MEAN IS FORECAST TO
INCREASE TO THE 0.9 TO 1.2 INCH RANGE BY LATE THIS EVENING AND
INTO THE OVERNIGHT. FOLLOWING THE LIGHT SHOWERS AND SPRINKLES
TRANSITIONING ACROSS THE SOUTHERN PARTS OF THE REGION LATE THIS
AFTERNOON/EARLY THIS EVENING, GUIDANCE GENERALLY HAS GREATER
COVERAGE OF CONVECTION DURING THE EVENING AND INTO THE OVERNIGHT.
MUCAPE INCREASES TO A FEW HUNDRED J/KG THROUGH THE EVENING AND
INTO THE OVERNIGHT ACROSS SOUTHERN LOCATIONS AND ISOLATED THUNDER
WILL BE POSSIBLE. A GENERAL LULL IN CONVECTION IS ANTICIPATED
INTO THURSDAY MORNING.
AS THE DAY PROGRESSES ON THURSDAY, GUIDANCE HAS MLCAPE INCREASING
TO AROUND 700 TO 1500 J/KG WITH MUCAPE PEAKING IN ROUGHLY THE
900 TO 2000 J/KG RANGE PER 12Z HREF. BULKS HEAR SHOULD RANGE FROM
ROUGHLY 30KT NORTH TO 40KT SOUTH. GIVEN SOME RECOVERY FOLLOWING
MORNING CLOUDS AND POSSIBLE CONVECTION, LOW LEVEL LAPSE RATES
SHOULD INCREASE TO AT LEAST 7 TO 8C/KM WITH MID LEVEL LAPSE RATES
AT LEAST NEARING 6.5C TO 7C/KM BEFORE INITIATION. SEVERAL CAMS
HAVE SOME UH SWATHS ACROSS MAINLY SOUTHERN PORTIONS OF THE AREA,
THOUGH THERE IS VARIABILITY FROM RUN TO RUN. 12Z HREF
PROBABILITIES ALSO WERE A MAXIMUM IN THE SOUTH. SPC HAS PLACED
SOUTHERN PORTIONS OF THE AREA IN A SLIGHT RISK FOR SEVERE
THUNDERSTORMS FOR THURSDAY AFTERNOON AND EVENING WITH A MARGINAL
RISK AS FAR NORTH AS NEAR THE MOUNTAIN PARKWAY. WIND MAY BE THE
PRIMARY THREAT, THOUGH WITH SOME ROTATING UPDRAFTS POSSIBLE AND
THE POTENTIAL FOR FREEZING LEVELS NEAR 10KFT AGL OR LOWER PER 12Z
HREF MEAN FORECAST SOUNDINGS, HAIL IS ALSO POSSIBLE. ANY STORMS
WILL ALSO HAVE SOME HEAVY RAIN RATES AS WELL. MODELS DO ALSO VARY
WITH TIMING OF THE THREAT, WITH THE 18Z HRRR HAVING TRENDED A BIT
LATER. WITH UNCERTAINTY ON HOW QUICKLY RECOVERY HAPPENS BEHIND
OVERNIGHT ACTIVITY AS WELL UNCERTAINTY AS TO HOW EARLY IN THE
AFTERNOON ANY ROBUST CONVECTION MAY OCCUR IS LOW. THE POTENTIAL IS
HIGHLIGHTED IN THE HWO AND IN SOCIAL MEDIA POSTS.
CHANCES FOR CONVECTION, AND ESPECIALLY THUNDER, WILL DECREASE BY
LATE THURSDAY EVENING INTO THURSDAY NIGHT AS THE FRONT MOVES
SOUTH, BUT WITH THE UPPER TROUGH AXIS LIKELY NEAR OR ACROSS
PORTIONS OF EASTERN KY, CHANCES WILL LINGER FOR MUCH OF THE AREA
THROUGH THE NIGHT.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 510 PM EDT TUE MAY 6 2025
THERE IS RELATIVELY GOOD AGREEMENT IN GUIDANCE FOR THE LONG TERM
PERIOD THROUGH SATURDAY, BOTH MODEL TO MODEL AND RUN TO RUN. THE
PERIOD WILL START WITH AN ELONGATED, POSITIVELY TILTED UPPER
TROUGH LAID OUT FROM THE SOUTHERN PLAINS THROUGH QUEBEC, AND AN
ASSOCIATED SURFACE FRONTAL BOUNDARY TO OUR NORTH FROM TX TO NEW
ENGLAND. A SECOND FRONTAL BOUNDARY WILL BE LAID OUT FURTHER SOUTH,
PREVENTING THE STYMIEING THE NORTHWARD FLOW OF SIGNIFICANT GULF
MOISTURE.
THE UPPER TROUGH AND SURFACE FRONT WILL PROGRESS SOUTHEASTWARD,
WITH THE COLD FRONT MOVING THROUGH KY ON THURSDAY AND THURSDAY
NIGHT. DESPITE SURFACE DEW POINTS EXPECTED TO MAKE IT ONLY INTO
THE 50S BEFORE COLD FROPA, THE ADVANCEMENT OF THE UPPER TROUGH
WITH ITS LOWERING GEOPOTENTIAL HEIGHTS AND ARRIVAL OF COLDER AIR
ALOFT SHOULD RESULT IN MODEST INSTABILITY. THIS WILL LIKELY RESULT
IN SHOWERS AND POSSIBLY SOME THUNDERSTORMS. AS THE COLD FRONT
DROPS TO OUR SOUTH, DRIER AND COOLER AIR WILL ARRIVE OVER KY
THURSDAY NIGHT INTO FRIDAY. AS THIS HAPPENS, A COUPLE OF UPPER
LOWS WILL PINCH OFF FROM THE TROUGH-- ONE OF THEM OVER THE
ARKLATEX REGION AND THE OTHER IN THE VICINITY OF NY/PA ON FRIDAY
AFTERNOON, WITH A COL IN BETWEEN OVER OUR AREA. THE NORTHERN ONE
WILL BE CLOSE TO THE PREVAILING WESTERLIES ALOFT AND IS EXPECTED
TO GET PICKED UP AND USHERED OUT AHEAD OF THE NEXT PROGRESSIVE
NORTHERN STREAM TROUGH. THE SOUTHERN LOW ESSENTIALLY BECOMES CUT
OFF AND LINGERS OVER THE LOWER MISSISSIPPI VALLEY. AT THIS POINT
IN THE FORECAST, EVEN THOUGH THE MOST RECENT RUNS OF THE GFS AND
ECMWF CONTINUE IN RELATIVELY GOOD AGREEMENT, RUN TO RUN CONTINUITY
IN THE MODELS OVER THE LAST DAY OR TWO FADES. AS IS OFTEN THE
CASE, THERE IS TROUBLE RESOLVING THE EVOLUTION OF A CUT OFF LOW
CONCERNING HOW IT WEAKENS AND MOVES. THE MOST RECENT RUNS SHOW A
NORTHEASTWARD DRIFT, WHICH BRINGS PRECIP INTO OUR AREA EARLY NEXT
WEEK. WITH A LACK OF CONFIDENCE IN HOW THINGS PLAY OUT, THE POP IS
ONLY IN THE SLIGHT CHANCE TO CHANCE RANGE (20-50%) FOR ANY GIVEN
FORECAST PERIOD EARLY NEXT WEEK.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 215 PM EDT WED MAY 7 2025
AS MOISTURE RETURNS NORTH SOME LOW TO MID LEVEL CLOUDS WERE
SPREADING NORTH AND EAST ACROSS THE AREA WITH SOME CUMULUS
DEVELOPMENT AS WELL. VFR WAS REPORTED ACROSS EASTERN KY, WITH A
FEW REDUCTIONS TO MVFR OR LOWER IN PARTS OF EASTERN TN. SOME
SPRINKLES OR LIGHT SHOWERS WERE OCCURRING AS THESE CLOUDS SPREAD
NORTH AND EAST. ISOLATED TO SCATTERED CONVECTION IS POSSIBLE AT
TIMES DURING THE FIRST 12 TO 18 HOURS OF THE PERIOD, WITH CHANCES
HIGHER BETWEEN 00Z AND 12Z AND HIGHEST IN THE SOUTHWEST NEAR KSME
AND KLOZ WHERE SOME PROB30 GROUPS WERE INCLUDED TO HIGHLIGHT THE
POTENTIAL FOR SOME MVFR REDUCTIONS. OTHERWISE, WITH INCREASING
MOISTURE, AN OVERALL TREND OF LOWERING CLOUD HEIGHTS IS
ANTICIPATED THROUGH 12Z. HOWEVER, PREVAILING VFR IS ANTICIPATED
IN ALL AREAS THROUGH ABOUT 06Z, WITH SOME MVFR CEILINGS FORECAST
TO DEVELOP/ SPREAD INTO THE KLOZ AND KSME AREA SOUTH TO THE TN
BORDER THROUGH 12Z WITHIN AND AFTER CONVECTION. SOME MVFR FOG, IF
NOT LOCALLY IFR IN SOME VALLEY LOCATIONS, MAY ALSO DEVELOP
WHEN/WHERE THERE ARE BREAKS OR A THINNING OF MID AND LOW LEVEL
CLOUDS AND FOLLOWING CONVECTION DURING THE 06Z TO 13Z TIMEFRAME. A
FEW REDUCTIONS WERE INCLUDED FOR ALL THE TAF SITES DURING THAT
TIME. OTHERWISE, DAYTIME HEATING AND MIXING AHEAD OF AN
APPROACHING COLD FRONT SHOULD LEAD TO A GENERAL IMPROVEMENT IN
CONDITIONS BETWEEN 12Z AND 18Z, WITH MVFR MORE PROBABLE TO LINGER
LATER NEAR KSME TO KLOZ SOUTH TO THE TN BORDER. SOME STRONGER
CONVECTION COULD BEGIN TO DEVELOP AND AFFECT KSME AND PERHAPS KLOZ
BEFORE THE END OF THE PERIOD, WITH COVERAGE LIKELY PEAKING JUST
AFTER THE END OF THE PERIOD. WINDS OUTSIDE OF ANY CONVECTION WILL
REMAIN LIGHT AND VARIABLE.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...JP
LONG TERM...HAL
AVIATION...JP
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