075  
FXUS63 KLMK 041929  
AFDLMK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LOUISVILLE KY  
229 PM EST SUN DEC 4 2022  
   
SHORT TERM
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 211 PM EST SUN DEC 4 2022  
 
A QUIET WEATHER DAY ACROSS SOUTHERN INDIANA AND CENTRAL KENTUCKY  
TODAY AS 1030MB HIGH PRESSURE MEANDERS ACROSS THE REGION. MID AND  
HIGH CLOUD CONTINUE TO ADORN THE SKIES OVER MUCH OF THE AREA, BUT  
CLEARING CONTINUES TO WORK IT'S WAY SOUTHWARD AS PLACES ROUGHLY  
NORTH OF I-64 SEE BLUER SKIES PREVAIL. KY MESONET SHOWS TEMPERATURES  
REACHING TO AROUND 40 SO FAR TODAY WITH CONTINUED LIGHT AND VARIABLE  
WINDS.  
 
EXPECT THE W-E ORIENTED WAVE OF HIGH CLOUD TO UNDULATE OVER THE NEXT  
12 HOURS OR SO, AS A GOOD AMOUNT OF CLEARING TAKES PLACE OVER MUCH  
OF THE CWA BEFORE FILLING BACK IN OVERNIGHT. THE BREAK IN CLOUD  
COVER SHOULD BE ENOUGH TO ALLOW TEMPERATURES TO FALL ONCE AGAIN INTO  
THE MID 20S NORTH OF THE PARKWAYS AND TO AROUND AND JUST ABOVE  
FREEZING THE CLOSER ONE GETS TO THE KY/TN BORDER.  
 
ON MONDAY, A WEAK SHORTWAVE WILL MOVE THROUGH THE ZONAL PATTERN  
ALOFT BRINGING RAIN CHANCES BACK TO THE AREA AS SOUTHERLY FLOW PULLS  
MOIST GULF AIR INTO THE REGION WITH PWATS BREACHING THE 90TH  
PERCENTILE ACCORDING TO SPC SOUNDING CLIMATOLOGY. THOUGH THERE IS  
GOOD AGREEMENT AMONG LATEST HI-RES MODELS ON RAIN ENTERING THE AREA  
MONDAY, TIMING DISCREPANCIES EXIST. MOST MODELS KEEP MUCH OF THE  
AREA DRY THROUGH THE MORNING, BUT A FEW ADVERTISE ONSET AS EARLY AS  
05/12Z NEAR BWG AND AREAS SW. WITH THAT BEING SAID, SOUTHERN KY, SAY  
SOUTH OF THE PARKWAYS, STANDS THE BEST CHANCE AT SEEING LIGHT  
RAINFALL MONDAY MORNING; OTHERWISE, RAIN SHOULD HOLD OFF UNTIL LATER  
MONDAY AFTERNOON. INCREASING CLOUD COVER AND RAINFALL WILL DECREASE  
THE EFFECTIVENESS OF WAA ASSOCIATED WITH SOUTHERLY FLOW, WITH  
AFTERNOON MAX TEMPERATURES REACHING 45-50F ACROSS SOUTHERN INDIANA  
AND NORTH CENTRAL KY AND 50-54F ROUGHLY SOUTH OF I-64. RAIN AND A  
GENERAL WET PATTERN WILL CONTINUE INTO THE LONG TERM PERIOD...MORE  
ON THAT BELOW.  
 

 
   
LONG TERM
 
(MONDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 226 PM EST SUN DEC 4 2022  
 
*********************************************************************  
 
KEY MESSAGES FOR NEXT WEEK:  
 
1) MULTIPLE ROUNDS OF RAINFALL EXPECTED THROUGH MUCH OF NEXT WEEK.  
LATEST TREND IN MODELS HAS BEEN TO SHIFT THE HEAVIEST AXIS OF RAIN  
FROM CENTRAL TENNESSEE INTO CENTRAL KENTUCKY.  
 
2) SEVERAL INCHES OF RAINFALL WILL BE POSSIBLE BY THE END OF THE  
WEEK. SOME OF THIS COULD RESULT IN HYDRO ISSUES, ESPECIALLY IF THE  
HEAVY RAINFALL AXIS SETS UP OVER OUR REGION.  
 
3) A THREAT FOR STRONG OR SEVERE STORMS, CONDITIONAL ON LOW TRACK  
AND ANY AVAILABLE INSTABILITY, WILL BE POSSIBLE THURSDAY INTO EARLY  
FRIDAY.  
 
*********************************************************************  
 
AN UNSETTLED PATTERN LOOKS TO DEVELOP IN THE LONG TERM WITH MULTIPLE  
ROUNDS OF PRECIPITATION LEADING TO POTENTIALLY SEVERAL INCHES OF  
ACCUMULATED RAINFALL BY THE END OF THE WEEK. A FRONTAL BOUNDARY OVER  
THE SOUTHERN U.S. WILL LIFT NORTHWARD NEAR OUR REGION AND WAVER  
THROUGH MIDWEEK, ALL WHILE SEVERAL PERTURBATIONS/WAVES WITHIN A  
SUBTROPICAL JET AT THE MID/UPPER LEVELS PASS OVERHEAD. COMBINE THIS  
WITH A NEAR CONSTANT, ENHANCED LOW/MID LEVEL MOISTURE FLUX OFF OF  
THE GULF OF MEXICO ALONG WITH SOME PACIFIC INFLUENCES... WIDESPREAD  
RAINS ARE A NEAR CERTAINTY FOR MOST.  
 
RAINFALL WILL LIKELY BE ONGOING FOR PORTIONS OF THE REGION MONDAY  
NIGHT AS THE FIRST WAVE ARRIVES. WE MAY SEE BREAKS IN SUBSEQUENT  
WAVES OF MOISTURE, BUT THEY WILL LIKELY BE SHORT-LIVED UNTIL ABOUT  
THURSDAY NIGHT OR FRIDAY WHEN A SHORTWAVE TROUGH AND ASSOCIATED COLD  
FRONT KICKS THROUGH THE REGION AND UPPER LEVEL RIDGING BUILDS IN  
BEHIND IT TO CHANGE UP THE PATTERN A BIT. A CONCERNING TREND IN  
MODELS OVER THE LAST 24 HOURS HAS BEEN TO SHIFT THE HEAVY RAIN AXIS  
FARTHER NORTH INTO CENTRAL KENTUCKY (WHEREAS PREVIOUSLY IT WAS OVER  
CENTRAL TENNESSEE). WE'VE SEEN MODELS WAVER WITH THE HEAVY RAIN AXIS  
OVER THE LAST SEVERAL DAYS, SO NOTHING IS SET IN STONE YET, BUT IT'S  
WORTH MONITORING BECAUSE ENSEMBLE MEAN/AVERAGES IN THE HEAVIEST RAIN  
AXIS TEND TO EXCEED 3", AND LOCALLY HIGHER AMOUNTS ARE A NEAR  
CERTAINTY GIVEN POTENTIAL FOR CONVECTIVELY ENHANCED RAINFALL (WHICH  
COARSER MODELS WON'T RESOLVE).  
 
GIVEN DRY ANTECEDENT CONDITIONS, WE SHOULD BE ABLE TO HANDLE A LOT  
OF THE RAIN FAIRLY WELL THROUGH THE FIRST PART OF THE WEEK, BARRING  
ANY SIGNIFICANT LOCALIZED/PERSISTENT HEAVY RAINS. AS WE GET CLOSER  
TO THE END OF THE WEEK, DEPENDING ON WHERE THE HEAVY RAIN AXIS HAS  
SET UP, WE MAY BEGIN TO SEE SOME HYDRO ISSUES ARISE AS SOGGY SOILS  
WILL BE LESS INCLINED TO ABSORB MODERATE TO HEAVY RAINFALL AHEAD OF  
THE SHORTWAVE TROUGH AND SURFACE COLD FRONT FOR THURSDAY/EARLY  
FRIDAY. WE MIGHT ALSO HAVE TO KEEP AN EYE OUT ON A LOW-END SEVERE  
THREAT THURSDAY INTO EARLY FRIDAY, DEPENDING ON THE TRACK OF THE LOW  
AND HOW FAR NORTH RICH LOW-LEVEL MOISTURE ADVECTS POLEWARD. THERE  
WILL BE PLENTY OF SHEAR IN PLACE AHEAD OF THE COLD FRONT, BUT  
INSTABILITY REMAINS VERY UNCERTAIN FOR ANY SEVERE POTENTIAL.  
 
THE SHORTWAVE TROUGH AND FRONT SHOULD CLEAR THE REGION SOMETIME  
FRIDAY. DRY CONDITIONS ARE EXPECTED IN ITS WAKE AS UPPER LEVEL  
RIDGING BUILDS IN, BUT IT MIGHT BE SHORT-LIVED AS YET ANOTHER SYSTEM  
MAY BE ON THE HEELS OF THE RIDGE AND IMPACT US LATE SATURDAY INTO  
SUNDAY.  
 

 
   
AVIATION
 
(18Z TAF ISSUANCE)  
ISSUED AT 1235 PM EST SUN DEC 4 2022  
 
IMPACTS: POTENTIAL MVFR CIGS IN LIGHT RAIN DURING SDF PLANNING  
PERIOD.  
 
DISCUSSION: EXPANSIVE SURFACE HIGH PRESSURE EXISTS ACROSS THE OH  
VALLEY TODAY AS HIGH CLOUDS STREAM OVERHEAD. LIGHT VARIABLE WINDS  
WILL CONTINUE THIS AFTERNOON BEFORE TAKING ON A MORE PREDOMINATELY  
SE DIRECTION OVERNIGHT AND INTO TOMORROW MORNING. CEILINGS WILL  
BEGIN TO DROP BY TUESDAY LATE MORNING WITH A CHANCE OF LIGHT RAIN  
ENTERING INTO BWG BY AS EARLY AS 05/15Z AND A FEW HOURS LATER AT THE  
OTHER TAF SITES (HNB AND LEX PROBABLY AROUND 20Z, JUST OUTSIDE OF  
THIS TAF CYCLE). CIGS WILL LIKELY DROP TO MVFR SHORTLY AFTER RAIN  
BEGINS WITH IFR CIGS LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING.  
 
CONFIDENCE: MEDIUM TO HIGH ON TIMING OF RAIN AND MVFR CIGS. HIGH ON  
ALL OTHER FORECAST ELEMENTS.  
 

 
   
LMK WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
KY...NONE.  

 
 

 
 
SHORT TERM...CG  
LONG TERM...DM  
AVIATION...CG  
 
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