087
FXUS63 KLMK 211123
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
623 AM EST SUN DEC 21 2025
..UPDATED AVIATION DISCUSSION
KEY MESSAGES
* COOLER TEMPERATURES ARE EXPECTED TODAY AND TONIGHT, BUT MILDER AIR
RETURNS BY MONDAY AFTERNOON.
* OFF AND ON CHANCES FOR LIGHT RAIN SHOWERS ARE EXPECTED MONDAY
AFTERNOON THROUGH MUCH OF THE WEEK. PRECIPITATION AMOUNTS ARE
EXPECTED TO BE LIGHT.
* UNSEASONABLY WARM TEMPERATURES ARE LIKELY AROUND CHRISTMAS, WITH
HIGHS IN THE 60S TO AROUND 70 LIKELY FROM CHRISTMAS EVE THROUGH
FRIDAY.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 321 AM EST SUN DEC 21 2025
THIS MORNING, A COLD FRONT IS SINKING INTO TENNESSEE AS SFC HIGH
PRESSURE CONTINUES TO BUILD OVER THE MID-MISSISSIPPI VALLEY. A
STRATUS DECK ALONG AND JUST BEHIND THE SFC FRONT IS EXPECTED TO SINK
SOUTH THROUGH THE REST OF THE MORNING, LEAVING US WITH SCATTERED TO
BROKEN HIGH CLOUDS FOR MOST OF THE REST OF TODAY. BEHIND THE FRONT,
WINDS ARE FAIRLY LIGHT OUT OF THE NORTHWEST, LEADING TO MODEST COLD
ADVECTION. AS A RESULT, TEMPERATURES SHOULD GRADUALLY FALL INTO THE
UPPER 20S AND LOW-TO-MID 30S BETWEEN NOW AND SUNRISE.
PLEASANT AND SEASONABLY COOL WEATHER IS EXPECTED TODAY WITH HIGH
TEMPERATURES RETURNING TO SLIGHTLY BELOW NORMAL LEVELS, RANGING FROM
THE LOW-TO-MID 40S ACROSS SOUTHERN IN AND NORTHERN KY TO THE UPPER
40S TO NEAR 50 ACROSS SOUTHERN KY. AS THE CENTER OF SFC HIGH
PRESSURE TREKS EAST ALONG I-70 TODAY, LIGHT NORTH-NORTHEAST FLOW
WILL CONTINUE, WITH WINDS GENERALLY BETWEEN 5-10 MPH. MODEL
SOUNDINGS DO SHOW THE POTENTIAL FOR ANOTHER DRY AIR MIXDOWN EVENT
THIS AFTERNOON GIVEN AMPLE DRY AIR ALOFT, SO WE'LL NUDGE AFTERNOON
TDS DOWN TO TRY AND ACCOUNT FOR THIS. THIS SHOULDN'T HAVE MUCH OF AN
EFFECT ON SENSIBLE WEATHER, ASIDE FROM MAKING IT MORE LIKELY FOR YOU
TO EXPERIENCE STATIC SHOCK.
THIS EVENING AND TONIGHT, TEMPERATURES WILL LIKELY FALL QUICKLY
AFTER SUNSET AS WINDS SHOULD BE LIGHT AND SKIES WILL BE MOSTLY
CLEAR. WHILE SOME OF THE TYPICAL COOL SPOTS IN THE BLUEGRASS MAY
FALL INTO THE LOW 20S AND POSSIBLY THE UPPER TEENS, THINK MOST AREAS
WILL RANGE FROM THE MID 20S TO AROUND 30 DEGREES AS WE START MONDAY
MORNING.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 321 AM EST SUN DEC 21 2025
MONDAY THROUGH TUESDAY NIGHT...
A DRY AND COLD START TO THE DAY ON MONDAY WILL BE SHORT-LIVED AS SFC
HIGH PRESSURE MOVES TOWARD THE MID-ATLANTIC, RESULTING IN WARM AND
MOIST RETURN FLOW INCREASING FROM THE SOUTH AND SOUTHWEST. WHILE WE
SHOULD START OUT WITH MAINLY SCATTERED HIGH CLOUDS MONDAY MORNING,
LOW- AND MID-LEVEL CLOUDS ARE EXPECTED TO INCREASE THROUGH THE DAY
AS VAPOR TRANSPORT INCREASES, ESPECIALLY IN THE 925-750 MB LAYER.
WHILE INCREASING LOW CLOUDS MAY SUBDUE WARMING LATER IN THE DAY,
SOUTHERLY FLOW NEAR THE SFC SHOULD ALLOW TEMPERATURES TO WARM INTO
THE 50S ACROSS THE AREA MONDAY AFTERNOON. AS A SOUTHWESTERLY H85 JET
CONTINUES TO STRENGTHEN ACROSS THE OHIO VALLEY MONDAY EVENING,
ISENTROPIC LIFT COMBINED WITH LOW-LEVEL MOISTURE SHOULD SUPPORT THE
DEVELOPMENT OF SCATTERED LIGHT RAIN SHOWERS.
COVERAGE OF RAIN SHOWERS SHOULD CONTINUE TO INCREASE MONDAY NIGHT AS
THE LLJ CONTINUES TO STREAM OVERHEAD. OVERALL RAINFALL AMOUNTS WILL
BE LIMITED BY SHALLOW MOISTURE DEPTH AND CONSIDERABLE DISPLACEMENT
FROM DEEPER FORCING. THOSE AREAS WHICH DO RECEIVE RAIN SHOWERS COULD
SEE UP TO A TENTH OF AN INCH OR TWO MONDAY AFTERNOON THROUGH
TUESDAY, SO NOTHING TOO IMPACTFUL. THE LLJ CORE IS EXPECTED TO MOVE
OFF TO THE EAST BY MIDDAY TUESDAY AS A SFC COLD FRONT SETTLES INTO
THE OHIO VALLEY FROM THE NORTH. THE GREATEST COVERAGE OF LIGHT RAIN
SHOWERS SHOULD SHIFT INTO SOUTHERN KY AND TN BY LATE IN THE DAY ON
TUESDAY, WITH PRECIPITATION AMOUNTS REMAINING LIGHT. WHILE THE
CURRENT TEMPERATURE FORECAST FEATURES HIGHS IN THE UPPER 50S AND LOW
60S ON TUESDAY, THERE IS INCREASED UNCERTAINTY WITH THIS FORECAST,
MAINLY RELATED TO PERSISTENT LLVL MOISTURE LIMITING SFC HEATING AND
KEEPING TEMPERATURES CLOSER TO 50 DEGREES.
THE SFC COLD FRONT SHOULD SETTLE ACROSS THE LOWER OHIO VALLEY
TUESDAY NIGHT, WITH LIGHT RAIN SHOWER/DRIZZLE CHANCES CONTINUING,
MAINLY ACROSS SOUTHERN KY. LOW TEMPERATURES WEDNESDAY MORNING WILL
BE HIGHLY VARIABLE ACROSS THE REGION THANKS TO THE WASHED OUT FRONT,
WITH UPPER 30S ACROSS CENTRAL IN AND MID 50S ACROSS SOUTHERN KY AND
TN.
CHRISTMAS EVE THROUGH CHRISTMAS NIGHT (THURSDAY NIGHT)...
AN UPPER-LEVEL RIDGE OVER THE SOUTH CENTRAL CONUS WILL FLEX SLIGHTLY
TO THE EAST WEDNESDAY INTO THURSDAY AS SHORTWAVE ENERGY EJECTING OUT
OF A DEEP SYNOPTIC TROUGH OFF THE WEST COAST STARTS TO ERODE HIGHER
HEIGHTS OVER THE NORTHERN US ROCKIES. THE SFC FRONT WHICH MOVED INTO
THE REGION ON TUESDAY IS EXPECTED TO LIFT BACK TO THE NORTH AS A
WARM FRONT WEDNESDAY INTO WEDNESDAY NIGHT, BRINGING ANOTHER CHANCE
FOR LIGHT RAIN SHOWERS ACROSS THE AREA DURING THIS TIME PERIOD.
STILL EXPECTING LIGHT RAIN AMOUNTS OVERALL AND A WASHOUT LOOKS
UNLIKELY.
WHAT WILL BE MORE NOTABLE FOR CHRISTMAS EVE AND CHRISTMAS DAY WILL
BE THE MILD TEMPERATURES, WHICH SHOULD CONTINUE THROUGH THE SECOND
HALF OF THE WEEK. THERE ARE NO SIGNIFICANT CHANGES IN FORECAST HIGHS
FROM THE PREVIOUS FORECAST ISSUANCE, WITH CHRISTMAS DAY STILL
LOOKING LIKE THE WARMEST DAY OF THE WEEK WITH HIGHS RANGING FROM THE
MID 60S TO THE LOW 70S. LOW TEMPERATURES MAY BE EVEN MORE ANOMALOUS
DURING THIS PERIOD, WITH A MOIST AIR MASS ONLY ALLOWING TEMPERATURES
TO FALL INTO THE 50S WEDNESDAY NIGHT AND THURSDAY NIGHT.
FRIDAY THROUGH SATURDAY NIGHT...
FORECAST CONFIDENCE DECREASE BY THE END OF THE WEEK INTO NEXT
WEEKEND, AS MODELS APPEAR TO BE STRUGGLING WITH HOW TO HANDLE ENERGY
EJECTING OUT OF THE WEST COAST TROUGH WHICH WILL GRADUALLY ERODE THE
UPPER RIDGE ACROSS THE CENTRAL AND EASTERN US. OVERALL, IT APPEARS
TO BE A FAIRLY ACTIVE PERIOD, AS MULTIPLE SHORTWAVES SHOULD BRING
CHANCES FOR PRECIPITATION TO THE AREA. HOWEVER, EXACTLY HOW STRONG
THESE SYSTEMS WILL BE WILL BE DEPENDENT ON UPPER-LEVEL WAVE PHASING,
WITH 500 MB CLUSTER ANALYSIS SHOWING QUITE A SPREAD AMONGST THE
ECMWF, GFS, AND CANADIAN ENSEMBLES. TAKING AN "ENSEMBLE MEAN"
APPROACH, THE CURRENT FORECAST GRADUALLY STEPS TEMPERATURES DOWN
INTO NEXT WEEKEND, WITH LOW POPS HIGHLIGHTING THE NEAR-PERSISTENT
POTENTIAL FOR PRECIPITATION GIVEN THE SIGNIFICANT SPREAD IN
GUIDANCE. STAY TUNED FOR SUBSEQUENT FORECAST UPDATES AS THIS SPREAD
SHOULD DECREASE LATER THIS WEEK.
AVIATION /12Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 623 AM EST SUN DEC 21 2025
VFR CONDITIONS AND LIGHT NORTHERLY WINDS ARE EXPECTED TODAY AS HIGH
PRESSURE SLIDES JUST TO THE NORTH OF THE AREA. SCATTERED HIGH CLOUDS
WILL CONTINUE THROUGH THIS AFTERNOON, WITH MOSTLY CLEAR SKIES
EXPECTED THIS EVENING INTO TONIGHT. WINDS SHOULD REMAIN LESS THAN 10
KT THROUGH THE DAY TODAY, GRADUALLY VEERING TO THE NE AND THEN THE E
BY EARLY MONDAY MORNING. BY THE END OF THE SDF TAF PERIOD, WINDS
WILL PICK UP AGAIN OUT OF THE S/SE, WITH CEILINGS EXPECTED TO DROP
LATER IN THE DAY ON MONDAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG
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