186
FXUS63 KLMK 182350
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
750 PM EDT SUN MAY 18 2025
..UPDATED AVIATION DISCUSSION
KEY MESSAGES
* SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON MONDAY. SOME
STORMS COULD BE STRONG OVER SOUTHERN KENTUCKY WITH GUSTY WINDS AND
MARGINALLY SEVERE HAIL.
* STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE MONDAY NIGHT AND
THROUGH THE DAY ON TUESDAY. THE HIGHEST RISK OF SEVERE WEATHER
WILL BE ON TUESDAY. DAMAGING WINDS, LARGE HAIL, AND ISOLATED
TORNADOES ARE POSSIBLE, ALONG WITH HEAVY RAINFALL.
* BELOW NORMAL TEMPERATURES EXPECTED LATE NEXT WEEK AND INTO THE
MEMORIAL DAY WEEKEND.
SHORT TERM /THROUGH MONDAY/
ISSUED AT 357 PM EDT SUN MAY 18 2025
AFTERNOON SATELLITE IMAGERY SHOWS A VEIL OF HIGH CLOUD COVER MOVING
ACROSS THE REGION. WATER VAPOR IMAGERY SHOWS A WEAK MID-LEVEL
VORTICITY MAX MOVING THOUGH IL/IN. WITH A BIT OF LOCAL HEATING AND
A SLIGHT THINNING OF THE HIGH CLOUDS, A BAND OF LIGHT SHOWERS HAS
DEVELOPED DOWN NEAR ROUGH RIVER. EXPECT THESE SHOWERS TO HOLD
TOGETHER FOR A BIT AND MOVE EASTWARD ACROSS PORTIONS OF NORTH-
CENTRAL AND INTO EAST-CENTRAL KY THIS AFTERNOON. WILL GENERALLY
CARRY AN EAST-WEST BAND OF ISOLATED-SCATTERED SHOWERS FROM NEAR
HARTFORD OVER TO AROUND STANDFORD, KY. AFTERNOON TEMPS WERE IN THE
LOW-MID 70S ACROSS THE REGION. WE EXPECT AFTERNOON HIGHS IN THE 75-
80 DEGREE RANGE. BEST SHOT AT 80 DEGREES STILL LOOKS TO BE SOUTH OF
THE CUMBERLAND PARKWAYS.
FOR TONIGHT, MID-LEVEL VORT MAX ACROSS IL/IN WILL SHIFT EASTWARD
RATHER QUICKLY WHILE MID-LEVEL HEIGHT RISES BUILD INTO THE REGION
FROM THE WEST. CONVECTION ACROSS EASTERN KS IS FORECAST TO PUSH
EASTWARD ACROSS MISSOURI OVERNIGHT AS IT ATTEMPTS TO ROUND THE TOP OF
THE RIDGE. SOME OF THIS ACTIVITY MAY MAKE IT INTO WESTERN KY LATE
TONIGHT AND TOWARD DAWN MONDAY MORNING. AS OF THIS WRITING, IT
APPEARS THAT THE BEST CHANCES OF ANY SHOWER ACTIVITY WILL LIKELY BE
WEST OF THE I-165 (NATCHER PARKWAY) CORRIDOR. HERE WE'LL CONTINUE
TO RUN SOME CHANCE POPS IN TONIGHT'S FORECAST. LOWS TONIGHT WILL
RANGE FROM THE LOWER-MID 50S OVER SE INDIANA AND INTO THE BLUEGRASS
REGION. UPPER 50S TO THE LOWER 60S WILL BE FOUND ELSEWHERE.
FOR MONDAY, REMNANT MCS ACTIVITY WILL LIKELY BECOME AN MCV AS IT
ROUNDS THE TOP OF THE MID-LEVEL RIDGE AXIS ACROSS WESTERN KY.
REMNANT CONVECTION IN THE FORM OF SHOWERS AND A FEW THUNDERSTORMS
WILL MOVE EAST SOUTHEAST ACROSS OUR SOUTHWEST CWA AND THEN DOWN INTO
CENTRAL/EASTERN TN DURING THE AFTERNOON. MODEL SOUNDINGS ACROSS OUR
REGION INDICATE A BROAD NORTHWESTERLY BUT DEEP NORTHWESTERLY FLOW
REGIME. THERE IS A BIT OF SPEED SHEAR SHOWING UP IN THE MODEL
SOUNDINGS MAINLY ACROSS SOUTHERN KY. MOISTURE PROFILES SUGGEST A
RATHER EXPANSIVE AREA OF CLOUD COVER ACROSS MUCH OF KENTUCKY WHICH
MAY TEMPER OVERALL AFTERNOON INSTABILITY. A CORRIDOR OF STRONGER
CONVECTION LOOKS TO BE CONFINED TO AREAS FROM BOWLING GREEN
SOUTHEASTWARD INTO CENTRAL/MIDDLE TN. OVERALL LAPSE RATES ACROSS
OUR REGION ARE RATHER MARGINAL, BUT COULD SUPPORT SCATTERED
SHOWERS/STORMS DURING THE AFTERNOON. THE CORE OF STEEPER LAPSE
RATES LOOKS TO BE FROM NASHVILLE SOUTHEASTWARD TOWARD CHATTANOOGA.
FOR NOW, WILL KEEP CHANCE POPS IN THE FORECAST WITH AFTERNOON HIGHS
IN THE MID-UPPER 70S ACROSS SOUTHERN INDIANA AND CENTRAL KENTUCKY.
SOUTHERN KY SHOULD SEE AFTERNOON HIGHS IN THE UPPER 70S TO THE LOWER
80S.
LONG TERM /MONDAY NIGHT THROUGH SUNDAY/
ISSUED AT 357 PM EDT SUN MAY 18 2025
MONDAY NIGHT THROUGH WEDNESDAY NIGHT...
HEADING INTO MONDAY NIGHT, A MID-LEVEL LOW OVER THE NORTHERN PLAINS
IS LIKELY TO STALL OUT AND PERHAPS SHIFT A BIT TO THE WEST BY
TUESDAY MORNING. ASSOCIATED SURFACE LOW OVER THE NORTHERN MO VALLEY
IS FORECAST TO OCCLUDE WITH A WARM FRONTAL BOUNDARY PUSHING
NORTHEASTWARD THROUGH THE OHIO VALLEY DURING THE EVENING HOURS.
THUNDERSTORMS ARE LIKELY TO BE IN PROGRESS ACROSS MUCH OF MO/AR
MONDAY EVENING. SURFACE WARM FRONT WILL PUSH NORTHEASTWARD DURING
THE EVENING PLACING MUCH OF KENTUCKY INTO THE WARM SECTOR. DURING
THE EVENING AND OVERNIGHT, THUNDERSTORMS WILL MOVE EASTWARD ACROSS
MO AND THEN INTO WESTERN KY AND WESTERN IN OVERNIGHT. THESE STORMS
WILL LARGELY BE DRIVEN BY ISENTROPIC ASCENT AND FED BY AN PLUME OF
ELEVATED INSTABILITY. THESE THUNDERSTORMS COULD BE STRONG TO SEVERE
HERE WITH TORRENTIAL RAINFALL, DAMAGING WINDS, AND HAIL BEING THE
MAIN SEVERE WEATHER THREATS.
THIS ACTIVITY IS THEN FORECAST TO PUSH OFF TO THE EAST/NORTHEAST
WHILE THE REMAIN REMAINS DEEP WITHIN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. MODEL GUIDANCE AT THIS TIME RANGE CONTINUES
TO VARY HERE WITH HOW THE MORNING CONVECTION WILL AFFECT AFTERNOON
CONVECTIVE DEVELOPMENT/EVOLUTION. THERE APPEAR TO BE TWO POSSIBLE
SCENARIOS THAT COULD OCCUR, WE'LL DISCUSS BELOW:
SCENARIO 1. MORNING CONVECTION MOVES OFF TO THE NORTHEAST AND WE
SEE A GOOD AMOUNT OF PARTIAL CLEARING DURING THE LATE MORNING AND
INTO THE AFTERNOON. IN MODELS THAT SUPPORT THIS IDEA, MODERATE TO
STRONG DESTABILIZATION WILL OCCUR IN THE AFTERNOON WITH STEEP LOW-MID
LEVEL LAPSE RATES. VERTICAL WIND SHEAR WILL INCREASE ACROSS THE
AREA AS 50-55 KT H5 JET OVERSPREADS THE REGION PLACING MUCH OF THE
AREA WITHIN THE FAVORED LEFT EXIT REGION. THESE MODEL PROFILES
WOULD SUGGEST A MIX OF SUPERCELLS AND MULTI-CELLS WITH LARGE HAIL,
DAMAGING WINDS AND ISOLATED/SCATTERED TORNADOES AS THE MAIN THREATS.
AS THE LOW-LEVEL JET INCREASES DURING THE LATE AFTERNOON/EVENING
EVENTUAL UPSCALE GROWTH INTO A QLCS WOULD BE LIKELY WITH
DAMAGING WINDS AND ISOLATED/SCATTERED SPIN UPS WITHIN THE LINE BEING
THE MAIN THREATS.
SCENARIO 2. MORNING CONVECTION IS SLOWER TO MOVE OFF OR PERSISTS FOR
LONGER THAN FORECAST WHICH DILUTES AN OTHERWISE SUPPORTIVE
ATMOSPHERIC ENVIRONMENT FOR SEVERE CONVECTION. HERE AFTERNOON
HEATING COULD EITHER BE COMPLETELY DISRUPTED OR PARTIALLY DISRUPTED
LEADING TO LOWER/LESS INTENSE CONVECTIVE COVERAGE AND STRENGTH.
THE CURRENT SPC SLIGHT RISK FOR OUR REGION APPEARS APPROPRIATE GIVEN
THE CURRENT UNCERTAINTIES WITH TUESDAY'S EVOLUTION. SHOULD WE END
UP GETTING MORE CLEARING, I CAN EASILY SEE THE ENHANCED RISK BEING
EXPANDED NORTHWARD IN SUBSEQUENT FORECASTS. BOTTOM LINE IS THAT
FOLKS SHOULD KEEP ABREAST OF THE LATEST FORECASTS AND PREPARE FOR
POSSIBLE SEVERE WEATHER ON TUESDAY.
THE SURFACE COLD FRONT IS FORECAST TO PUSH THROUGH THE REGION
TUESDAY NIGHT ENDING THE THREAT OF SEVERE WEATHER AND USHERING IN A
COOLER AIRMASS. HIGHS ON TUESDAY WILL BE DEPENDENT ON CONVECTION,
BUT FOR NOW WILL GO WITH MID-UPPER 70S OVER OUR NORTH AND LOWER 80S
OVER THE SOUTH. LOWS TUESDAY NIGHT WILL DROP BACK INTO THE UPPER
50S/LOWER 60S.
BROAD NORTHWEST FLOW IS EXPECTED FOR WEDNESDAY AND INTO WEDNESDAY
NIGHT WITH SMALL SCALE PERTURBATIONS POSSIBLY LEADING TO ADDITIONAL
PERIOD OF RAIN SHOWERS ON WEDNESDAY. HIGHS WILL RANGE FROM THE
UPPER 60S TO THE VERY LOW 70S WITH OVERNIGHT LOWS IN THE UPPER
40S/LOWER 50S.
THURSDAY THROUGH SUNDAY...
THE OVERALL PATTERN ALOFT WILL REMAIN SOMEWHAT AMPLIFIED FOR THE
REMAINDER OF THE WEEK OVER THE CONUS. MAIN FEATURE WILL BE
PERSISTENT TROUGHING OVER THE NORTHEAST US WHICH WILL KEEP THE OHIO
VALLEY WITHIN A BROAD NORTHWESTERLY FLOW AND THAT WILL KEEP
TEMPERATURES BELOW LATE MAY NORMALS. WEAK PERTURBATIONS COMING
THROUGH WITHIN THE FLOW MAY BRING EPISODIC BOUTS OF RAIN SHOWERS TO
THE REGION. HIGHS THURSDAY AND FRIDAY WILL LIKELY TOP OUT IN THE
UPPER 60S WITH UPPER 60S/LOWER 70S POSSIBLE BY SATURDAY AND SUNDAY.
OVERNIGHT LOWS WILL GENERALLY BE IN THE UPPER 40S TO THE LOWER 50S.
AVIATION /00Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 749 PM EDT SUN MAY 18 2025
VFR CONDITIONS EXPECTED TONIGHT WITH BKN CIRRUS. NW WINDS INITIALLY
AROUND 5 KT WILL BECOME LIGHT AND VARIABLE LATE THIS EVENING, WHILE
GRADUALLY VEERING OUT OF THE NE BY EARLY MONDAY MORNING. A BATCH OF
SHOWERS AND PERHAPS ISO TO SCT TSRA DEVELOPING ACROSS KS AND MO
OVERNIGHT WILL ATTEMPT TO MOVE ESE OVER PORTIONS OF SOUTHERN IN AND
WEST/CENTRAL KY ON MONDAY. HNB AND BWG HAVE THE BEST CHANCE AT
SEEING A PERIOD OF SHOWERS, ALONG WITH BRIEF MVFR CIGS/VSBYS.
CEILINGS WILL GENERALLY LOWER INTO THE 3-5 KFT RANGE LATE MORNING
INTO THE AFTERNOON.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...EBW
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