782
FXUS63 KLMK 290754
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
354 AM EDT SAT MAR 29 2025
KEY MESSAGES
* WARM TEMPERATURES AND BREEZY SOUTH WINDS CONTINUE TODAY, WITH
ISOLATED TO SCATTERED LIGHT/MODERATE RAIN SHOWERS EXPECTED THIS
EVENING INTO TONIGHT.
* CONFIDENCE CONTINUES TO INCREASE FOR STRONG TO SEVERE STORMS
SUNDAY NIGHT, WHICH WILL BE CAPABLE OF ALL SEVERE HAZARDS (WIND,
HAIL, TORNADO, LOCALLY HEAVY DOWNPOURS).
* ANOTHER STRONG LOW PRESSURE SYSTEM COULD BRING WINDY CONDITIONS TO
THE REGION WEDNESDAY, AND THUNDERSTORMS, POSSIBLY STRONG,
WEDNESDAY INTO WEDNESDAY NIGHT.
* ADDITIONAL SHOWERS AND STORMS MAY CONTINUE INTO THURSDAY AND
FRIDAY, LEADING TO SIGNIFICANT RAINFALL TOTALS BY THE END OF THE
WEEK.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 353 AM EDT SAT MAR 29 2025
EARLY THIS MORNING, WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW
EXTENDING ACROSS THE LOWER MISSISSIPPI VALLEY. MID- AND UPPER-LEVEL
MOISTURE ADVECTION HAS BROUGHT INCREASING CLOUDS INTO THE TENNESSEE
AND OHIO VALLEYS SINCE FRIDAY EVENING, WITH BROKEN 15-20 KFT CLOUDS
OBSERVED ACROSS THE AREA AT 07Z. A 40-45 KT SOUTHERLY 850 MB JET IS
NOTED ON LATEST SPC HOURLY MESOANALYSIS; HOWEVER, MOST OF THE LOW-
LEVEL MOISTURE ADVECTION IS REMAINING WEST OF THE MISSISSIPPI AT
THIS TIME. THE BETTER LOW-LEVEL MOISTURE IS GENERALLY EXPECTED TO
REMAIN WEST OF THE AREA THROUGH THE MORNING HOURS, WHICH WILL HELP
IN KEEPING PRECIPITATION CHANCES AT A MINIMUM.
TODAY, THE UPPER LOW TO OUR SOUTHWEST WILL GRADUALLY GET ABSORBED
INTO THE ZONAL FLOW PATTERN EAST OF THE ROCKIES AS ANOTHER SHORTWAVE
EJECTS FROM THE FOUR CORNERS INTO THE CENTRAL HIGH PLAINS. H85
RIDGING OFF THE CAROLINA COAST WILL REMAIN FIXED IN PLACE, KEEPING
MODERATELY STRONG S/SW LOW-LEVEL FLOW OVER THE TENNESSEE AND OHIO
VALLEYS. ONCE BOUNDARY LAYER MIXING STARTS UP IN THE MID-LATE
MORNING, BREEZY CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON HOURS,
WITH SOUTH WINDS OF 10-20 MPH AND WIND GUSTS OF 20-30 MPH LIKELY. AS
THE AFOREMENTIONED MID-LEVEL SHORTWAVE EJECTS INTO THE PLAINS LATER
TODAY, HEIGHT FALLS ALONG AND WEST OF THE MISSISSIPPI SHOULD BEGIN
TO NUDGE THE LOW-LEVEL MOISTURE PLUME TOWARD THE I-65 CORRIDOR.
CLOUDS SHOULD GRADUALLY THICKEN AND BUILD DOWNWARD THIS AFTERNOON
AND EVENING FROM WEST TO EAST. HI-RES MODEL GUIDANCE SHOWS ISOLATED
TO SCATTERED SHOWERS DEVELOPING DURING THE MID-TO-LATE AFTERNOON
HOURS ON THE LEADING EDGE OF HIGHER 850 MB THETA-E VALUES, THOUGH
THE WIDE VARIATION IN RAIN SHOWER COVERAGE AND LOCATION IN MODEL
GUIDANCE MEANS THAT FORECAST CONFIDENCE IS LOW OUTSIDE OF A GENERAL
EXPECTATION OF INCREASING COVERAGE FROM WEST TO EAST DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. TEMPERATURES TODAY SHOULD BE
SOMEWHAT COOLER THAN ON FRIDAY GIVEN INCREASED CLOUD COVER, WITH MID-
70S TO NEAR 80 DEGREES EXPECTED FOR HIGHS TODAY.
THIS EVENING AND TONIGHT, LOW-LEVEL MOISTURE ADVECTION WILL LEAD TO
PERSISTENT ISOLATED TO SCATTERED RAIN SHOWERS WITHIN THE WARM
ADVECTION REGIME. RAIN SHOWER COVERAGE SHOULD BECOME MORE NUMEROUS
AFTER MIDNIGHT TONIGHT, WITH A 70-80% POP IN PLACE FOR THE OVERNIGHT
PERIOD, THOUGH NO PARTICULAR AREA IS FAVORED WITHIN THE CWA. TOTAL
PRECIPITATION AMOUNTS TODAY AND TONIGHT SHOULD BE LIGHT, GENERALLY
LESS THAN 0.25" OUTSIDE OF A HEAVIER SHOWER. WHILE SOUTHERLY WINDS
WILL BECOME LESS GUSTY AFTER SUNSET THIS EVENING, SOUTH WINDS AROUND
10 MPH SHOULD CONTINUE OVERNIGHT. AS A RESULT, UNSEASONABLY MILD
TEMPERATURES WILL CONTINUE INTO SUNDAY MORNING, WITH LOWS ONLY
FALLING INTO THE UPPER 50S AND LOW-TO-MID 60S.
LONG TERM /SUNDAY THROUGH FRIDAY/
ISSUED AT 353 AM EDT SAT MAR 29 2025
SUNDAY - SUNDAY NIGHT...
THE OVERALL FORECAST THINKING HAS NOT CHANGED SIGNIFICANTLY FOR
SUNDAY AND SUNDAY NIGHT. SEVERE STORMS APPEAR LIKELY SUNDAY NIGHT
(AFTER 00Z MONDAY), AND THESE STORMS WILL POSE A RISK FOR DAMAGING
WINDS, TORNADOES, AND LARGE HAIL.
A LEAD SHORTWAVE IMPULSE WILL LIFT OFF TO THE NORTHEAST SUNDAY
MORNING AS THE LLJ WEAKENS. SCATTERED SHOWERS WILL LIKELY BE ONGOING
AT THE START OF THE PERIOD, BUT THE ATMOSPHERE REMAINS FAIRLY STABLE
THROUGH THE MORNING HOURS.
THE PRIMARY MID/UPPER LEVEL TROUGH WILL SWING NORTHEAST FROM THE
CENTRAL PLAINS ACROSS PORTIONS OF THE MID MS VALLEY AND MIDWEST
SUNDAY BEFORE REACHING THE GREAT LAKES EARLY MONDAY MORNING. WE'LL
SEE EXCELLENT DIFFLUENCE ALOFT SUNDAY EVENING AND SUNDAY NIGHT AS A
POTENT MID-LEVEL JET STREAMS NORTHEAST FROM THE OZARKS ACROSS
SOUTHERN INDIANA.
AT THE SURFACE, A SUB-1000 MB LOW INITIALLY NEAR THE QUAD CITIES IS
FORECAST TO GRADUALLY DEEPEN AS IT TRACKS TO CENTRAL LOWER MI BY
EVENING. DEEP SW FLOW WILL REMAIN IN PLACE IN THE WARM SECTOR AHEAD
OF THE APPROACHING COLD FRONT, WHICH IS STILL FORECAST TO PASS
THROUGH THE FORECAST AREA EARLY MONDAY MORNING. SFC DEWPOINTS WILL
WASTE NO TIME IN CLIMBING INTO THE UPPER 50S TO LOWER 60S.
MEANWHILE, WE DO SEE AN EML ADVECT EASTWARD OVER THE REGION DURING
THE DAY ON SUNDAY. A STRONGER CAPPING INVERSION ALOFT SHOULD KEEP
CONVECTIVE ACTIVITY TO A MINIMUM THROUGH THE AFTERNOON HOURS,
ALLOWING INSTABILITY TO BUILD ALOFT DESPITE FAIRLY ABUNDANT LOW
CLOUDS.
THE STRONGER FORCING PROVIDED BY THE UPPER LEVEL TROUGH AND LOW-
LEVEL COLD FRONT WILL ALLOW DEEP CONVECTION TO DEVELOP AND PROGRESS
ACROSS PORTIONS OF EASTERN MO, IL, AND WESTERN KY SUNDAY AFTERNOON
AND EVENING. THESE STORMS STILL APPEAR LIKELY TO CONGEAL INTO A LINE
JUST AHEAD OF THE SYNOPTIC COLD FRONT AS THEY PUSH EAST ACROSS KY
AND SOUTHERN IN.
THE MOST LIKELY TIME FOR SEVERE WEATHER APPEARS TO BE FROM 9-10 PM
EDT SUNDAY THROUGH 6 AM EDT MONDAY. FORECAST MODELS AND SOUNDINGS,
INCLUDING THE LATEST 00Z HI-RES DATA, SUGGEST SBCAPE COULD BRIEFLY
PEAK BETWEEN 1000-1500 J/KG IN A NARROW PLUME JUST AHEAD OF THE
CONVECTIVE LINE. THIS IS CONCERNING GIVEN THE STRONG (40-50 KTS)
DEEP-LAYER SHEAR IN PLACE. HODOGRAPHS SHOW A GOOD AMOUNT OF
CURVATURE IN THE LOWEST 1 KM, WITH A LONG HODOGRAPH ABOVE THAT. VERY
STRONG 0-1 KM SHEAR AND 0-1 KM SRH EXCEEDING 250 M2/S2 ALSO SUPPORT
A SUBSTANTIAL TORNADO THREAT. QLCS TORNADOES ARE TYPICALLY EF-0 AND
EF-1 (STILL VERY DANGEROUS!), BUT SOME MODEL FORECAST SOUNDINGS DO
SUPPORT THE IDEA OF A SIGNIFICANT TORNADO (AT LEAST EF-2 RATING)
TOMORROW NIGHT.
BROADER BUOYANCY ALOFT WILL ALSO SUPPORT A LARGE HAIL THREAT,
ESPECIALLY OVER THE WESTERN 2/3 OF THE FORECAST AREA. THE MOST
LIKELY THREAT, AS WITH MOST QLCSS, IS DAMAGING WINDS. AND GIVEN THE
INSTABILITY/SHEAR PARAMETER SPACE, ISOLATED 70-80 MPH WINDS WILL BE
POSSIBLE.
TEMPERATURES IN THE LOW TO MID 70S WILL BE COMMON SUNDAY, WITH
READINGS FALLING INTO THE 50S EARLY MONDAY.
MONDAY-TUESDAY...
ONCE THE SHOWERS AND STORMS MOVE OFF TO THE EAST EARLY MONDAY
MORNING WE'LL HAVE A BREAK FROM THE STORMY WEATHER AS A LONG NORTH-
SOUTH RIDGE OF HIGH PRESSURE SLIDES FROM THE PLAINS TO THE EAST
COAST. HIGHS WILL RETURN TO THE MID 50S TO LOWER 60S, WITH LOWS IN
THE 30S EARLY TUESDAY MORNING.
WEDNESDAY-FRIDAY...
THE NEXT SEASONABLY STRONG SURFACE LOW WILL CROSS THE UPPER MIDWEST
AND UPPER GREAT LAKES WEDNESDAY-WEDNESDAY NIGHT. SURFACE WINDS WILL
BE STRONG AND GUSTY HERE ON WEDNESDAY, AND MID/UPPER SUPPORT WITH
THIS SYSTEM MAY ACTUALLY BE STRONGER THAN THE SUNDAY NIGHT SYSTEM.
ECMWF EFI IS SHOWING UNUSUAL CAPE-SHEAR MAGNITUDES. MOST RECENT ML
PROGS FROM NSSL AND CSU HAVE THE GREATEST SEVERE CHANCES OVER THE
LOWER/MID MS VALLEY AND LOWER OH VALLEY. STILL TOO EARLY TO PUT ANY
SPECIFICS ON IT, BUT RESIDENTS OF SOUTHERN INDIANA AND CENTRAL
KENTUCKY SHOULD KEEP IN MIND THAT AFTER SUNDAY NIGHT'S STORMS, MORE
STRONG TO SEVERE STORMS ARE A POSSIBILITY WEDNESDAY NIGHT.
OF SOME ADDITIONAL CONCERN IS THAT THE LATEST MODEL GUIDANCE
CONTINUES TO POINT TO THE POSSIBILITY OF A STALLING FRONTAL BOUNDARY
WEDNESDAY NIGHT THROUGH THE END OF THE WEEK. MULTIPLE WAVES RIDING
NORTHEAST ALONG THIS BOUNDARY COULD SPELL AN INCREASING FLOODING
THREAT ACROSS SOUTHERN IN AND CENTRAL KY.
AVIATION /06Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 134 AM EDT SAT MAR 29 2025
SOUTH WINDS AROUND 5-10 KT AND BROKEN MID-LEVEL CLOUDS ARE EXPECTED
TO CONTINUE THROUGH THE MID-MORNING HOURS. A 40 KT S/SW LLJ WILL
BRING MARGINAL LLWS CONDITIONS TO AREA TERMINALS THIS MORNING UNTIL
WE MIX OUT THE NEAR-SFC STABLE LAYER. ONCE THIS MIXES OUT, STRONGER
S/SW WINDS ARE EXPECTED THROUGH THE DAY, WITH 20-25 KT GUSTS LIKELY
THROUGH LATE AFTERNOON. BY MID-LATE AFTERNOON, SCATTERED RAIN
SHOWERS ARE EXPECTED TO DEVELOP AND GRADUALLY PUSH FROM WEST TO
EAST. WITH CONTINUED UNCERTAINTY ON TIMING AND COVERAGE, AND MINIMAL
IMPACTS EXPECTED, HAVE CUT BACK ON SHRA MENTION UNTIL LATER IN THE
FORECAST PERIOD. TONIGHT INTO TOMORROW MORNING, CEILINGS WILL
CONTINUE TO DROP, WITH SDF/BWG/HNB LIKELY APPROACHING MVFR CEILINGS
BY THE END OF THE CURRENT FORECAST PERIOD.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...CSG
LONG TERM...EBW
AVIATION...CSG
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