734
FXUS63 KLMK 211947
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
347 PM EDT THU MAY 21 2026
KEY MESSAGES
* REMNANT SHOWERS THIS EVENING WILL BECOME SPOTTY IN SOUTHERN AREAS
WITH TEMPERATURES HOVERING IN THE MID 50S TO LOW 60S.
* WARM FRONT MOVES NORTH THROUGH THE AREA, BRINGING WIDESPREAD RAIN
FRIDAY MORNING. BUILDING INSTABILITY WILL CREATE A MARGINAL RISK
FOR SEVERE GUSTY WINDS, A SMALL CHANCE OF A TORNADO, AND A FLASH
FLOOD THREAT WITH HEAVY DOWNPOURS.
* SCATTERED LIGHTER RAINFALL IS EXPECTED ON SATURDAY. ADDITIONAL
WAVES OF SHOWERS AND STORMS WILL BE POSSIBLE SUNDAY INTO THE
MIDDLE OF NEXT WEEK. LOCALIZED EXCESSIVE RAINFALL MAY RESULT IN
FLOODING.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 347 PM EDT THU MAY 21 2026
REMNANT SHOWERS WITH LIGHT TO MODERATE RAIN REMAINS IN EAST-CENTRAL
KY WHERE SOME DECENT RAIN TOTALS HAVE FALLEN. HIGH TEMPERATURES
UNDERPERFORMED FROM A COOL NE FLOW AND CONTINUED CLOUD/RAIN COVERAGE
TODAY. PWAT VALUES REMAINED HIGH ENOUGH WITH CONTINUAL MOISTURE
TRANSPORT TO KEEP MOST PLACES SOCKED IN WITH MOISTURE AND LOW
CLOUDS. A FEW SOUTHERN BORDER COUNTIES WARMED INTO THE LOW TO MID
70S SINCE THEY WERE FURTHER AWAY FROM THE BEST LIFT OF THE INCOMING
FRONT. AS THE EVENING PROGRESSES, THIS TRAILING COLD FRONT WILL
GRADUALLY PUSH THE MOISTURE TOWARDS THE SOUTHEASTERN CWA BORDER THIS
EVENING AND TONIGHT. TEMPERATURES OVERNIGHT WILL REMAIN IN THE MID
50S TO LOW 60S. THERE COULD STILL BE SOME RAIN CHANCES ALONG OUR
SOUTHERN BORDER OVERNIGHT, THOUGH ANY RAIN TO FALL WILL BE LIGHT,
GENERALLY IN THE FORM OF SPRINKLES, THOUGH LOW-END POPS CONTINUE
OVERNIGHT FOR THOSE AREAS.
BY FRIDAY MORNING, THE SYNOPTIC WEATHER PATTERN SHIFTS AS A
NEGATIVELY TILTED TROUGH SWINGS THROUGH THE NORTHERN PLAINS. THIS
TROUGH WILL HELP FORM A NEW SURFACE LOW SWINGING IN FROM THE GULF
STATES, BRINGING IN WIDESPREAD RAINFALL IN THE MORNING AHEAD OF AN
INCOMING WARM FRONT. LIGHT TO MODERATE, AND SOMETIMES HEAVY RAINFALL
IS EXPECTED WITH THIS SWATH OF STRATIFORM RAIN MOVING IN, FURTHER
HELPING TO RELIEVE DROUGHT CONDITIONS.
HOWEVER, BY EARLY AFTERNOON FRIDAY, THE NEWLY FORMED SURFACE LOW
WILL INDUCE A LOW TO MID-LEVEL JET OVER CENTRAL KY. WITH PLENTY OF
MOISTURE STREAMING IN FROM THE SW, PWAT VALUES WILL BE HIGH IN THE
1.5 - 2" RANGE IN THE AFTERNOON. ADDITIONALLY, AFTER THE INITIAL
SWATH OF RAIN MOVES TO OUR NE, CLOUD COVER MAY BEGIN TO BREAK,
ALLOWING ADDITIONAL DAYTIME HEATING TO OCCUR ACROSS SOUTH/CENTRAL
KY. SO WITH PLENTY OF MOISTURE, 30 KT SURFACE TO 500 MB SHEAR, AND
INCREASING INSTABILITY FRIDAY AFTERNOON, THERE IS POTENTIAL FOR
CLUSTERS OF STORMS OR SUPERCELLS TO FORM BECOMING SEVERE IN THE
AFTERNOON. SPC HAS ISSUED A MARGINAL RISK FOR SEVERE WEATHER, AND
WITH CURRENT CAPE VALUES AND MODEL LAPSE RATES, THE SEVERE RISK IS
FROM STRONG TO SEVERE GUSTY WINDS ALONG WITH A SMALL CHANCE OF A
TORNADO. AS STORMS ROLL IN FROM THE SOUTH AND WEST, THERE WILL BE
PLENTY OF MOISTURE TO WORK WITH, CREATING A FLASH FLOOD THREAT FOR
STORMS OR HEAVY RAIN THAT TRAINS OVER THE SAME AREAS. 6HR LPMM DATA
FROM THE LATEST HREF RUN INDICATES LOCALIZED AREAS OF 2-4+" INCHES
ARE POSSIBLE IN TRAINING STORMS. THIS FLOODING THREAT WILL BE
MONITORED AS THE EVENT PROGRESSES AND MAY NEED TO ISSUE A FLOOD
WATCH IN OUR CWA, ESPECIALLY CONSIDERING THE AMOUNT OF RAIN OUR
CENTRAL/SOUTHERN COMMUNITIES HAVE SEEN TODAY. TEMPERATURES WILL BE
WARM TOMORROW AFTERNOON, WITH HIGHS IN THE LOW TO UPPER 70S. AS
FRIDAY EVENING APPROACHES, STORMS LINGERING IN THE AREA WILL WEAKEN
WITH THE LOSS OF DAYTIME HEATING, AND THE SEVERE THREAT WILL END
JUST AFTER SUNSET.
LONG TERM /SATURDAY THROUGH THURSDAY/
ISSUED AT 347 PM EDT THU MAY 21 2026
A MID-LEVEL SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WILL CONTINUE
NORTHEAST ACROSS INDIANA FRIDAY NIGHT. DEEP-LAYER SW FLOW CONTINUES
WITH PW VALUES REMAINING IN THE 1.6-1.8 INCH RANGE. NUMEROUS SHOWERS
AND SCATTERED THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF
THIS FORECAST PERIOD 00Z SATURDAY. CONVECTIVE INTENSITY SHOULD
GRADUALLY WANE OVERNIGHT DUE TO DECREASING INSTABILITY, WITH
THUNDERSTORMS MORE ISOLATED IN NATURE BY THE EARLY MORNING HOURS OF
SATURDAY.
THE WAVE OF LOW PRESSURE CONTINUES OFF TO THE NORTHEAST ACROSS THE
GREAT LAKES SATURDAY AND SATURDAY NIGHT, TAKING THE STRONGER FORCING
AND DEEPER MOISTURE WITH IT. THIS WILL RESULT IN SCATTERED, LIGHTER
INTENSITY SHOWERS ON SATURDAY, WITH RAIN CHANCES GRADUALLY
DECREASING FROM WEST TO EAST SATURDAY AFTERNOON AND EVENING. MOST
PLACES SHOULD BE ABLE TO BRIEFLY DRY OUT SATURDAY EVENING AND
OVERNIGHT. LOWS IN THE LOW 60S WILL BE COMMON, WITH SATURDAY
AFTERNOON HIGHS IN THE MID/UPPER 70S.
BY SUNDAY, AN UPPER LEVEL TROUGH DEVELOPS OVER TEXAS WITH A DEEPER
WAVE SWINGING NORTHEAST ACROSS ONTARIO AND THE UPPER MIDWEST.
OVERALL FORCING ISN'T ALL THAT STRONG, BUT WE WILL STILL HAVE A
MOIST LOW-LEVEL AIRMASS IN PLACE WITH WEAK CONVERGENCE ALONG A
REMNANT BOUNDARY. SCATTERED STORMS APPEAR POSSIBLE SUNDAY,
ESPECIALLY IN THE AFTERNOON AND EVENING HOURS AS THE MOIST AIRMASS
DESTABILIZES. FORECAST CONFIDENCE IN THE DETAILED EVOLUTION IS LOW,
BUT THE OVERALL THREAT FOR ORGANIZED SEVERE CONVECTION LOOKS LOW DUE
TO WEAK SHEAR. LOCALIZED HEAVY RAINFALL IS POSSIBLE IN SLOW-MOVING
SHOWERS AND STORMS.
A MID/UPPER LEVEL LOW SLOWLY MEANDERS NORTH OVER THE SOUTHERN PLAINS
THROUGH EARLY NEXT WEEK, WITH DOWNSTREAM CONFLUENT FLOW OVER THE
OHIO VALLEY. A QUASI-STATIONARY SFC BOUNDARY WITH DEEP MOISTURE (PW
VALUES 1.5-1.75 INCHES) POOLED ALONG IT WILL VERY SLOWLY DRIFT
NORTHWARD OVER THE TN AND LOWER OH VALLEYS. THIS WILL BRING
ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE REGION, AND THE RAINFALL
COULD BE HEAVY AT TIMES WITH AT LEAST AN ISOLATED RISK FOR FLOODING.
AVIATION /18Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 154 PM EDT THU MAY 21 2026
IFR-LOW END MVFR CONDITIONS WILL CONTINUE INTO THE EVENING AND
OVERNIGHT HOURS. LIGHT TO MODERATE RAIN SHOWERS IN THE EAST WILL END
OVER THE NEXT FEW HOURS THOUGH CEILINGS WILL STRUGGLE TO IMPROVE
ACROSS THE AREA. OCCASIONAL HIGH-END MVFR TO LOW-END VFR CONDITIONS
COULD RETURN TO HNB-SDF OVERNIGHT BEFORE THEY LOWER AGAIN AFTER
SUNRISE. OTHERWISE, LIGHT NE WINDS WILL PERSIST INTO TOMORROW
MORNING, WITH CEILINGS REMAINING LOW BETWEEN IFR-MVFR CONDITIONS
THROUGH FRIDAY. IN THE MORNING, WINDS BEGIN TO SHIFT OUT OF THE E TO
SE WITH A WIDE SWATH OF LIGHT TO MODERATE RAIN FOR ALL AIRPORTS
MOVING IN FROM THE SOUTHWEST. IF CEILINGS IMPROVE IN THE MORNING,
THEY WILL LOWER ONCE AGAIN WITH THE WIDESPREAD INCOMING RAIN ON
FRIDAY, WHICH WILL BECOME MORE SCATTERED AND MIXED WITH STORMS IN
THE AFTERNOON. LEX/RGA MAY DIP INTO LIFR CONDITIONS WITH THE CURRENT
CEILING FORECAST IN THE MORNING INTO THE AFTERNOON AS WELL.
OTHERWISE, MVFR TO IFR CONDITIONS ARE EXPECTED FOR EVERYONE FRIDAY
AFTERNOON.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...BKF
LONG TERM...EBW
AVIATION...BKF
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