967
FXUS63 KLMK 300141
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
941 PM EDT THU MAY 29 2025
KEY MESSAGES
* WIDESPREAD RAIN ALONG WITH SCATTERED THUNDERSTORMS WILL SPREAD
ACROSS THE AREA LATE TONIGHT INTO TOMORROW MORNING.
* A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE EARLY TOMORROW
MORNING INTO THE START OF THE DAY, MAINLY ACROSS SOUTH CENTRAL KY
ALONG THE KY/TN BORDER. DAMAGING WINDS AND A LOW-END THREAT OF
TORNADOES ARE THE MAIN HAZARDS.
* HEAVY RAINFALL COULD LEAD TO PONDING AND STANDING WATER ON AREA
ROADS/HIGHWAYS DURING THE MORNING COMMUTE AND ALSO LEAD TO
LOCALIZED FLOODING CONCERNS.
* MAINLY DRY THIS WEEKEND WITH SPOTTY SHOWERS AT TIMES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
* DRY AND WARMER EARLY NEXT WEEK WITH HIGHS IN THE 80S.
UPDATE
ISSUED AT 941 PM EDT THU MAY 29 2025
WEAK ISENTROPIC LIFT ACROSS THE REGION HAS RESULTED IN PATCHY LIGHT
RAIN SHOWERS MOVING THROUGH SOUTHERN INDIANA AND NORTH-CENTRAL KY
THIS EVENING. TEMPERATURES REMAIN MILD ACROSS THE REGION WITH LOWER-
MIDDLE 60S OVER SOUTHERN IN AND UPPER 60S TO AROUND 70 ACROSS MUCH
OF CENTRAL/SOUTHERN KY. ANOTHER CLUSTER OF CONVECTION WAS NOTED
DOWN ACROSS THE LAKE CUMBERLAND REGION. THIS ACTIVITY CONTINUES TO
WEAKEN WHILE PUSHING SOUTH AND EAST.
FOR THE OVERNIGHT PERIOD, A FAIRLY STRONG MID-LEVEL WAVE WILL PUSH
THROUGH THE BASE OF AN AMPLIFYING UPPER LEVEL TROUGH AXIS MOVING
THROUGH THE OHIO VALLEY. A SURFACE LOW WILL MOVE FROM ARKANSAS
NORTHEASTWARD THROUGH SOUTHERN KY OVERNIGHT. WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THIS WAVE. LATEST
EVENING DATA CONTINUES TO SHOW FAIRLY MARGINAL/MODEST INSTABILITY
ACROSS THE REGION OVERNIGHT. ON THE OTHER HAND, THE SHEAR PROFILES
DO BECOME MORE FAVORABLE OVERNIGHT FOR ORGANIZED CONVECTION. THERE
REMAINS A LOW RISK OF SEVERE WEATHER ACROSS THE SOUTHERN THIRD OF KY
OVERNIGHT. DESPITE THE MARGINAL INSTABILITY, THE WIND PROFILES
COULD SUPPORT A SUPERCELL OR TWO THAT WOULD MOVE GENERALLY
ALONG/SOUTH OF THE CUMBERLAND PARKWAY. DAMAGING WINDS, MARGINALLY
SEVERE HAIL, AND AN ISOLATED TORNADO CAN NOT BE RULED OUT WITH THIS
ACTIVITY. MODERATE TO HEAVY RAINFALL WILL BE POSSIBLE WITH THE
OVERNIGHT ACTIVITY AS SYNOPTIC SCALE FORCING (WE'LL BE IN THE LEFT
EXIT REGION OF THE H5 JET) WILL BE MAXIMIZED OVER SOUTHERN KY.
RAINFALL AMOUNTS OF 1-2 INCHES WILL BE POSSIBLE. SO PONDING OF
WATER ON ROADWAYS AND LOCALIZED HYDRO ISSUES MAY IMPACT THE MORNING
COMMUTE.
MUCH OF THIS ACTIVITY WILL PULL QUICKLY EASTWARD FRIDAY MORNING AND
THEN WE'LL GET INTO A DEEPER NORTHWEST FLOW REGIME. LAPSE RATES
WILL STEEPEN THROUGH THE AFTERNOON HOURS RESULTING IN ADDITIONAL
SCATTERED CONVECTION WHICH COULD PRODUCE SMALL HAIL IN THE STRONGEST
CORES.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 328 PM EDT THU MAY 29 2025
WEAK, LOW-LEVEL CONVERGENCE SOUTH OF THE PARKWAYS TO THE KY/TN
BORDER HAS HELPED SPARK A FEW SHOWERS AND ISOLATED THUNDERSTORMS
THIS AFTERNOON. IN THIS AREA WE HAVE AROUND 1000-1500 J/KG OF SBCAPE
BUT WEAK SHEAR. MAIN THREAT FROM ANY SHOWER OR ISOLATED STORM WILL
BE A BRIEF HEAVY DOWNPOUR. THIS ACTIVITY WILL LIKELY DIMINISH CLOSE
TO AFTER SUNSET AS WE LOSE THE DAYTIME HEATING.
A STRONG MID-LEVEL SHORTWAVE TROUGH CURRENTLY STRETCHING FROM THE
GREAT LAKES BACK INTO IA IS EXPECTED TO DEEPEN AND SWING THROUGH
THE OHIO VALLEY LATE TONIGHT THROUGH THE DAY TOMORROW. A STRONG MID-
LEVEL JET STREAK TO THE SOUTH AND WEST OF THE TROUGH WILL WORK
ACROSS CENTRAL TN/SOUTHERN KY TONIGHT INTO EARLY TOMORROW MORNING.
MOST OF SOUTH CENTRAL KY WILL BE IN THE LEFT EXIT REGION OF THIS JET
STREAK. AT THE SURFACE, A SFC LOW IS EXPECTED TO DEVELOP OVER THE
MISSOURI BOOTHEEL AND DEEPENS AS MOVES ACROSS CENTRAL KY FROM THE
WEST TO THE EAST TONIGHT INTO TOMORROW. WIDESPREAD SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM WILL START TO MOVE INTO
CENTRAL KY/SOUTHERN IN BY AROUND 08Z AND THEN INTO EASTERN KY BY
AROUND 14Z. SPC HAS UPDATED THE DAY 1 OUTLOOK TO INCLUDE ALL OF
SOUTH CENTRAL KY IN A MARGINAL RISK (1 OUT OF 5) FOR SEVERE WEATHER
LATE TONIGHT INTO EARLY MORNING HOURS. THIS IS IN LINE WITH WHERE WE
THINK THE BEST CHANCE FOR THUNDERSTORMS WILL BE AS IT CORRESPONDS
WITH THE LOCATION OF THE WARM FRONT AND PATH OF THE DEEPENING SFC
LOW ACROSS THE COMMONWEALTH. MUCAPE WILL BE BETWEEN 500-1000 J/KG,
WEAK MID-LEVEL LAPSE RATE AND STRONG WESTERLY SHEAR. DAMAGING WINDS
AND A LOW-END TORNADO THREAT WILL BE THE MAIN SEVERE CONCERNS.
ALONG WITH THE SEVERE THREAT ACROSS SOUTH CENTRAL KY, HEAVY RAINFALL
IS A THREAT ACROSS OUR ENTIRE CWA. PWAT VALUES WILL SURGE TO 130%
ABOVE NORMAL OR 1.4" TO 1.6" WITH RAINFALL AMOUNTS RANGING BETWEEN 1
TO 2 INCHES EXPECTED WITH THE MAIN WAVE OVERNIGHT INTO TOMORROW
MORNING. POUNDING ON AREA ROADS AND HIGHWAYS DURING THE MORNING
COMMUTE ALONG WITH LOCALIZED FLASH FLOODING WILL BE THE MAIN
CONCERN.
ONCE THE MORNING WAVE OF SHOWERS AND THUNDERSTORMS PUSHES THROUGH,
WE WILL SEE SOME PARTIAL CLEARING WITH JUST SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS IN THE AFTERNOON. THE MAIN TROUGH AXIS SWINGS
THROUGH TOMORROW AFTERNOON AND COULD DEVELOP A BROKEN LINE OF
SHOWERS AND STORMS. AS COOLER AIR FILTERS IN ALOFT WE WILL SEE
STEEPENING MID-LEVEL LAPSE RATES. SMALL HAIL OR GRAUPEL IS POSSIBLE
WITH ANY SCATTERED CONVECTION THAT DEVELOPS IN THE AFTERNOON.
LONG TERM /SATURDAY THROUGH THURSDAY/
ISSUED AT 328 PM EDT THU MAY 29 2025
THIS WEEKEND...
A RELATIVELY STATIC PATTERN IS EXPECTED OVER THE WEEKEND AS
AMPLIFIED MID- AND UPPER-LEVEL TROUGHING WILL LINGER ALONG THE EAST
COAST AS RIDGING BUILDS ACROSS THE WESTERN CONUS. SEVERAL TRANSIENT
SHORTWAVES WILL SWING ALONG THE WESTERN EDGE OF THE UPPER TROUGH,
PASSING ACROSS THE OHIO AND TENNESSEE VALLEYS SATURDAY INTO SUNDAY.
OVERALL MOISTURE CONTENT WILL BE FAIRLY LIMITED; HOWEVER, MODEL
SOUNDINGS DO SHOW ELEVATED RHS IN THE 925-850 MB LAYER SATURDAY
AFTERNOON. WHEN COMBINED WITH 7.5-8 DEGREE LOW-LEVEL LAPSE RATES AND
SOME FORCING FROM AN UPPER JET STREAK AND A SECONDARY COLD FRONT,
WOULD EXPECT THERE TO BE AT LEAST ISOLATED TO SCATTERED SHOWERS AND
A FEW THUNDERSTORMS SATURDAY AFTERNOON AND EVENING.
THE BACKDOOR COLD FRONT SHOULD PRESS THROUGH THE AREA SATURDAY NIGHT
INTO SUNDAY MORNING, WITH TYPICAL DIURNAL MINIMUM IN INSTABILITY
LEADING TO DIMINISHING PRECIP COVERAGE OVERNIGHT. ANOTHER CHANCE FOR
SHOWERS AND A STORM OR TWO IS POSSIBLE ACROSS SOUTHERN KY AS WE
DESTABILIZE ON SUNDAY, ALTHOUGH IF THE FRONT IS FASTER IN CLEARING
THE AREA, PRECIPITATION CHANCES MAY BE LOWER THAN CURRENTLY
ADVERTISED. BEHIND THE FRONT, NORTH-NORTHWEST WINDS SHOULD BRING IN
DRIER AIR, WITH DEWPOINT TEMPERATURES FALLING INTO THE 40S AND LOW
50S BY SUNDAY EVENING. THIS SHOULD BRING AN END TO RAIN CHANCES AS
WE HEAD INTO THE BEGINNING OF NEXT WEEK. TEMPERATURES THIS WEEKEND
SHOULD BE NEAR TO SLIGHTLY BELOW NORMAL, WITH COOLER TEMPERATURES
EXPECTED THE FARTHER NORTH AND EAST YOU GO.
EARLY NEXT WEEK...
THE BEST CHANCES FOR DRY WEATHER IN THE EXTENDED FORECAST PERIOD
LOOK TO BE SUNDAY NIGHT THROUGH TUESDAY NIGHT AS UPPER RIDGING AND
SURFACE HIGH PRESSURE MOVE ACROSS THE AREA. ENSEMBLE MEAN PW VALUES
BELOW THE 10TH PERCENTILE OF CLIMATOLOGY REINFORCE THE NOTION THAT A
DRY AIR MASS WILL BE IN PLACE, WHICH SHOULD ALLOW FOR PRETTY LARGE
DIURNAL SWINGS IN TEMPERATURES. MONDAY MORNING, TEMPERATURES SHOULD
START OUT IN THE 50S IN MOST AREAS, WITH SOME UPPER 40S LIKELY IN
THE COOLER SPOTS. AMPLE SUNSHINE MONDAY WILL HELP TEMPERATURES WARM
INTO THE UPPER 70S AND LOWER 80S FOR HIGHS, WHICH IS NEAR
CLIMATOLOGICAL NORMALS. MONDAY NIGHT INTO TUESDAY, THE SFC HIGH
PRESSURE WILL BEGIN TO PUSH TOWARD THE CAROLINAS AS TROUGHING WEST
OF THE ROCKIES BEGINS TO NUDGE EASTWARD. THIS SHOULD INCREASE
WARM/MOIST RETURN FLOW BY TUESDAY AFTERNOON INTO WEDNESDAY, WITH
ABOVE NORMAL TEMPERATURES EXPECTED AS WE HEAD INTO THE MIDDLE OF
NEXT WEEK.
MIDDLE OF NEXT WEEK...
SUCCESSIVE SHORTWAVES EJECTING OUT OF THE WESTERN CONUS WILL BEGIN
TO BREAK DOWN THE UPPER RIDGE OVER THE SOUTHEASTERN U.S. BY THE
MIDDLE OF NEXT WEEK. MOISTURE RETURN COMBINED WITH THE GRADUAL
BREAKDOWN OF THE UPPER RIDGE SHOULD ALLOW FOR DAILY SHOWER AND STORM
CHANCES TO RETURN NEXT WEDNESDAY INTO THURSDAY. THERE IS STILL
FAIRLY DECENT SPREAD IN HOW STRONG PASSING SHORTWAVES WILL BE MID-TO-
LATE NEXT WEEK; HOWEVER, A STRONGER MID- AND UPPER-LEVEL WAVE COULD
INTRODUCE THE POTENTIAL FOR STRONG TO SEVERE STORMS, PARTICULARLY
NEXT THURSDAY. HOWEVER, CONFIDENCE IN THIS IS QUITE LOW AT THIS
TIME, BUT IS SOMETHING THAT WE WILL HAVE TO WATCH. FOR WHAT IT'S
WORTH, LONG-RANGE AI/ML GUIDANCE DOES SHOW A MODEST SIGNAL FOR
STRONG/SEVERE STORMS DURING THIS PERIOD, THOUGH NOTHING IS
PARTICULARLY CONCERNING AT THIS TIME.
AVIATION /00Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 733 PM EDT THU MAY 29 2025
COMPACT LOW PRESSURE SYSTEM IS FORECAST TO PUSH EASTWARD THROUGH THE
REGION TONIGHT. PRIOR TO THAT A BAND OF LIGHT RAIN WILL MOVE
THROUGH SOUTHERN IN AND NORTHERN KY THOUGH CIGS/VSBYS LOOK TO REMAIN
VFR WITH THIS ACTIVITY. LATER TONIGHT, AFOREMENTIONED LOW PRESSURE
SYSTEM WILL MOVE TOWARD THE REGION AND BRING WIDESPREAD SHOWERS TO
SOUTHERN INDIANA AND CENTRAL KENTUCKY. A BAND OF THUNDERSTORMS WILL
LIKELY IMPACT THE SOUTHERN PART OF KY INTO NORTHERN TN PRIMARILY
AFFECTING KBWG AND PERHAPS RGA. BEST TIME FOR STORMS AT BWG/RGA
WOULD BE BETWEEN 30/08-30/12Z. BEHIND THE SYSTEM, WINDS WILL KICK
AROUND TO THE NORTHWEST AND BECOME QUITE BREEZY. ADDITIONAL
SCATTERED SHOWERS AND POSSIBLE STORMS WILL BE SEEN DURING THE
AFTERNOON HOURS AS LAPSE RATES STEEPEN IN THE WAKE OF THE PASSING
LOW.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
UPDATE.......MJ
SHORT TERM...BTN
LONG TERM....CSG
AVIATION.....MJ
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