748
FXUS63 KJKL 081253
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
853 AM EDT THU MAY 8 2025
KEY MESSAGES
- THE PERIODIC POTENTIAL FOR SHOWERS AND THUNDERSTORMS CONTINUE
INTO NEXT WEEK, WITH CHANCES PEAKING THIS AFTERNOON AND MONDAY
INTO TUESDAY.
- SOME OF THUNDERSTORMS THIS AFTERNOON AND EVENING, MAINLY SOUTH
OF THE MTN PKWY, COULD BE STRONG TO SEVERE WITH GUSTY TO
DAMAGING WIND GUSTS, LARGE HAIL, AND HEAVY RAIN POSSIBLE.
- TEMPERATURES WILL AVERAGE NEAR NORMAL INTO THE UPCOMING
WEEKEND.
UPDATE
ISSUED AT 845 AM EDT THU MAY 8 2025
SHOWERS WERE MOVING ACROSS AREAS GENERALLY SOUTH OF THE INTERSTATE
64 CORRIDOR WITH SOME EMBEDDED THUNDER SOUTH OF THE MTN PARKWAY
AND NEARER TO THE CUMBERLAND PARKWAY/HAL ROGERS PARKWAY/KY 80
CORRIDOR. HOURLY GRIDS, ESPECIALLY POPS AND TEMPERATURES, HAVE
BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AS WELL AS GUIDANCE
AND OBSERVATION TRENDS.
AS FOR STRONG TO SEVERE THUNDERSTORM POTENTIAL DURING THE
AFTERNOON TO EARLY EVENING, BY 18Z, THE SPC MESOANALYSIS BASED ON
THE RAP BRINGS MLCAPE TO 1000 J/KG OR MORE ALONG AND SOUTH OF A
LINE FROM NEAR THE PULASKI/ROCKCASTLE COUNTY LINE TO CLAY COUNTY
TO LETCHER COUNTY AT 18Z/2 PM EDT WITH EFFECTIVE SHEAR IN THAT
REGION OF 30 TO 40KT. LOW LEVEL LAPSE RATES AT THAT POINT ARE
FORECAST AROUND 6.5C/KM WITH MID LEVEL LAPSE RATES OF 6.5 TO
7C/KM. LATER IN THE AFTERNOON TO EARLY EVENING, GUIDANCE GENERALLY
HAS INSTABILITY INCREASING SOMEWHAT FURTHER (PENDING BREAKS IN THE
CLOUDS), WITH STEEPENING LOW LEVEL LAPSE RATES ESPECIALLY, AND
SOME POTENTIAL FOR MID LEVEL LAPSE RATES TO INCREASE SLIGHTLY AS
WELL. HODOGRAPHS DO HAVE SOME LENGTH AS WELL. THE EVOLUTION OF
CONVECTION ACROSS THE CENTRAL AND NORTHERN PORTION OF THE AREA
LEADS TO THE MOST UNCERTAINTY THERE, THOUGH CLOUDS SHOULD KEEP
CONVECTION LESS INTENSE. HOWEVER, SOUTH OF THE
BOUNDARY/DIFFERENTIAL HEATING BOUNDARY/OUTFLOW, SEVERAL CAMS RUNS
HAVE SOME UH SWATHS IN THESE MORE SOUTHERN LOCATIONS LATE IN THE
AFTERNOON TO EARLY EVENING AND 00Z HREF UH PROBABILITIES WERE
HIGHEST THERE AS WELL. PARAMETERS AND CAMS GENERALLY SUPPORT THE
POTENTIAL FOR A COUPLE OF SUPERCELLS TO DEVELOP, IN THE MORE
SOUTHERN COUNTIES. THESE COULD PRODUCE LARGE HAIL PERHAPS AS HIGH
AS THE 1 TO 2 INCH DIAMETER RANGE (ESPECIALLY NEAR TO THE TN AND
VA BORDER), DAMAGING WINDS, AND SOME HEAVY RAIN.
UPDATE ISSUED AT 1156 PM EDT WED MAY 7 2025
A QUICK LITTLE EVENING UPDATE TO ACCOUNT FOR THE SHOWERS THAT HAVE
DEVELOPED ACROSS THE AREA. ALSO, INCORPORATED THE LATEST SURFACE
OBS INTO THE GRIDS. LATE EVENING TEXT AND RADIO PRODUCTS HAVE BEEN
UPDATED TO REFLECTED THE CHANGES. GRIDS HAVE BEEN SAVED AND SENT.
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
(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 609 PM EDT WED MAY 7 2025
A SURFACE COLD FRONT WILL BE DEPARTING TO OUR SOUTH EARLY FRIDAY,
WHILE AN UPPER TROUGH OVER THE AREA CONTINUES ITS SLOW SOUTH
SOUTHEASTWARD TREK. A FEW LINGERING SHOWERS ASSOCIATED WITH THESE
FEATURES MIGHT BE FOUND OVER OUR SOUTHERN AND SOUTHEASTERN
COUNTIES AS WE MOVE INTO THE DAY, BUT THEY WILL BE WANING AND ON
THE WAY OUT. SURFACE RIDGING SETTLING SOUTH FROM THE GREAT LAKES
OVER THE MIDWEST WILL SEND US A COOLER AND MUCH DRIER AIR MASS
WITH DECREASING CLOUDS THROUGH THE DAY. THIS WILL SET US UP FOR
CHILLY TEMPERATURES FOR THIS TIME OF YEAR ON FRIDAY AND SATURDAY
NIGHTS, WITH THE COLDEST VALLEYS POSSIBLY SLIPPING BELOW 40.
THE AFOREMENTIONED UPPER TROUGH WILL FEATURE A CLOSED LOW NEAR THE
LOWER GREAT LAKES EARLY ON FRIDAY. THIS WILL GET PICKED UP AND
USHERED OUT TO THE NORTHEAST BY ANOTHER PROGRESSIVE NORTHERN
STREAM TROUGH AS WE MOVE INTO THE WEEKEND. THIS WILL LEAVE A PIECE
OF THE ORIGINAL UPPER TROUGH TO DROP TO THE LOWER MISSISSIPPI
VALLEY, PINCHING OFF ANOTHER CLOSED LOW. IT IS EXPECTED TO BECOME
CUT OFF, OR NEARLY CUT OFF, FROM THE NORTHERN STREAM FLOW FROM
WHENCE IT ORIGINATED. THESE LOWS OFTEN HAVE A TENDENCY TO BE
DIFFICULT FOR MODELS TO HANDLE, ESPECIALLY IN TERMS OF WHEN THEY
WILL BEGIN TO OPEN UP AND GET ABSORBED BACK INTO THE FLOW AND
MOVE. HOWEVER, THE ECMWF AND GFS CONTINUE IN REASONABLE AGREEMENT
NOT ONLY MODEL TO MODEL, BUT NOW ALSO RUN TO RUN. THAT BEING THE
CASE, FORECAST CONFIDENCE IS A BIT HIGHER THAN YESTERDAY. PRECIP
FROM THIS SYSTEM COULD BEGIN TO SHOW UP FROM THE SOUTHWEST LATE IN
THE WEEKEND, BUT IS MOST FAVORED FROM LATE MONDAY INTO TUESDAY,
AT WHICH TIME LIKELY POPS HAVE BEEN INTRODUCED INTO THE FORECAST.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 719 AM EDT THU MAY 8 2025
SHOWERS AND THUNDERSTORMS MOVING ACROSS EASTERN KY THIS MORNING,
WITH A BIT OF A BREAK MID-MORNING BEFORE ADDITIONAL, STRONGER
STORMS DEVELOP OVER THE AREA THIS AFTERNOON/EVENING ALONG A COLD
FRONT PUSHING SOUTH. DEVELOPMENT WILL INITIALLY BE SCATTERED
BEFORE INCREASING IN COVERAGE, ESPECIALLY IN AREAS FURTHER SOUTH.
PATCHES OF MVFR CEILINGS THIS MORNING SHOULD RISE TO VFR DURING
THE BREAK IN PRECIPITATION, BEFORE RETURNING TO MVFR AND IFR WITH
THE STORMS. WIDESPREAD IFR CONDITIONS ARE EXPECTED TOWARDS THE END
OF THE PERIOD, WITH LOW CEILINGS AND BR FILLING IN BEHIND THE
COLD FRONT. THE FRONT WILL ALSO CHANGE PREDOMINANT WIND DIRECTION
FROM VARIABLE TO DEFINITIVELY NORTHERLY BY 12Z FRIDAY, THOUGH
SPEEDS WILL REMAIN GENERALLY LIGHT (<10 KTS) THROUGH THE PERIOD
SAVE FOR GUSTS ASSOCIATED WITH STORMS.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...JP
SHORT TERM...JP
LONG TERM...HAL
AVIATION...CAMDEN/SGF
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