491  
FXUS63 KPAH 151110  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
510 AM CST SUN DEC 15 2024  
   
KEY MESSAGES
 
 
- THE NEXT ROUND OF WIDESPREAD MODERATE TO HEAVY RAINFALL MOVES  
THROUGH LATE TONIGHT INTO MONDAY WITH ANOTHER 0.5 TO 1.5 INCHES  
OF RAINFALL. A STRONGER STORM WITH SMALL HAIL IS POSSIBLE  
MONDAY MORNING IN SOUTHEAST MISSOURI.  
 
- AFTER A DRY DAY ON TUESDAY, MORE RAIN MOVES THROUGH TUESDAY  
NIGHT INTO WEDNESDAY. ANOTHER 0.5 TO 1.0 INCHES OF RAINFALL  
IS POSSIBLE.  
 
- AN ARCTIC COLD FRONT MOVES THROUGH WEDNESDAY NIGHT.  
TEMPERATURES WILL PLUMMET AND REMAIN BELOW NORMAL THROUGH NEXT  
WEEKEND, WITH WIND CHILL VALUES FALLING INTO THE TEENS. A FEW  
SNOW FLURRIES MAY EVEN RETURN FRIDAY AS AN ALBERTA CLIPPER  
PASSES BY TO THE NORTH.  
 

 
   
DISCUSSION
 
 
ISSUED AT 243 AM CST SUN DEC 15 2024  
 
GOES-16 SATELLITE IMAGERY SHOWS A VERTICALLY STACKED LOW NOW LIFTING  
NORTHEAST ACROSS ILLINOIS THIS MORNING AS THE LAST BROKEN LINE OF  
SHOWERS IS NOW BEGINNING TO EXIT PORTIONS OF SOUTHWEST INDIANA AND  
WESTERN KENTUCKY. LINGERING AREAS OF DRIZZLE WILL CONTINUE TO REMAIN  
POSSIBLE ALONG AND EAST OF I-57 THROUGH THIS MORNING AS THE BOUNDARY  
LAYER REMAINS SATURATED. IN THE MID-LEVELS, WATER VAPOR SHOWS  
THE DRY-CONVEYOR BELT ADVECTING IN AS THE REST OF TODAY WILL END  
UP BEING A RELATIVELY DRY DAY WITH A WEAK RIDGE AXIS BUILDING  
ALOFT. HOWEVER, THERE WILL BE ENOUGH OF INVERSION TO KEEP A LOW  
STRATUS DECK IN PLACE FOR MOST OF THE DAY WITH THE EXCEPTION OF  
MAYBE THE FAR NW WHERE SOME BREAKS OF SUN ARE MORE LIKELY. HIGH  
TEMPS WILL BE MILDER IN THE UPPER 50S TO NEAR 60.  
 
A HIGHLY PROGRESSIVE SYNOPTIC FLOW ALOFT MEANS THE NEXT CHANCE OF  
UNSETTLED WEATHER QUICKLY ARRIVES TONIGHT AS ANOTHER SHORTWAVE  
TROUGH DIGS SOUTHEAST FROM THE NORTHERN PLAINS. WHILE THE BETTER  
LARGE- SCALE FORCING AT 500 MB WILL BE WELL TO THE NORTHEAST, A  
LEADING SUBTLE IMPULSE COMBINED WITH SOME BETTER FORCING AT 850 MB  
WILL CAUSE A CLUSTER OF SHOWERS AND EMBEDDED ELEVATED  
THUNDERSTORMS TO DEVELOP LATE TONIGHT INTO MONDAY MORNING FROM  
SOUTHWEST TO NORTHEAST. MEANWHILE, PWATS MAY NOW NEAR 1.5 INCHES,  
WHICH IS ABOUT 3 STANDARD DEVIATIONS ABOVE NORMAL. WHILE THE HREF  
IS SHOWING ABOUT A 60% PROBABILITY OF GREATER THAN 1 INCH OF  
RAINFALL OVER A 3 HOUR PERIOD, FFG REMAINS ABOVE 2 INCHES FOR MOST  
AREAS DESPITE THE POTENTIAL FOR TORRENTIAL DOWNPOURS. AT MOST,  
SOME RUNOFF WILL BE POSSIBLE IN MORE PRONE LOCATIONS, BUT OVERALL  
THE FLOODING RISK REMAINS LOW. ADDITIONAL TOTAL QPF BETWEEN 0.5 TO  
1.5 INCHES IS EXPECTED.  
 
AS FOR THE LOW CONDITIONAL SEVERE RISK THAT HAS PREVIOUSLY BEEN  
MENTIONED, THE THERMODYNAMICS LOOK ABOUT THE SAME WITH THE  
HRRR/RAP SUPPORTING ABOUT 400-700 J/KG OF MUCAPE, IN LINE WITH  
WHAT THE ECMWF HAS BEEN ADVERTISING THE LAST COUPLE OF DAYS.  
MID-LEVEL LAPSE RATES ARE STILL ABOUT 6.5-7.0 C/KM AT BEST AS  
MODEST HEIGHT FALLS CAUSES SOME COOLING ALOFT. WHILE THE SFC  
PARAMETERS ARE STILL LACKING DUE TO A CAPPING INVERSION JUST  
ABOVE THE SFC, 25 KTS OF EFFECTIVE BULK SHEAR IS ENOUGH TO  
SUPPORT AT LEAST ISOLATED SMALL HAIL IN SOUTHEAST MISSOURI. IF  
MOISTURE AND INSTABILITY WERE TO SLIGHTLY OVERACHIEVE, A  
STRONGER STORM WOULD NOT BE OUT OF THE QUESTION. FOR NOW, THE  
SEVERE RISK STILL REMAINS FAIRY MUTED WITH "GENERAL THUNDER"  
PROGGED BY THE SPC IN THEIR D1/D2 CONVECTIVE OUTLOOK.  
 
WHILE INSTABILITY WANES BY MONDAY AFTERNOON, A LINE OF SHOWERS  
WITH EMBEDDED RUMBLES OF THUNDER WILL CONTINUE EAST OF THE  
MISSISSIPPI BEFORE EXITING MONDAY EVENING. IN THE WAKE OF A  
COLD FRONT MONDAY NIGHT, HIGH TEMPS WILL BE UNSEASONABLY WARM IN  
THE LOW TO MID 60S. COOLER AND DRIER CONDITIONS CAN BE EXPECTED  
TUESDAY WITH HIGHS IN THE LOW TO MID 50S AS HIGH PRESSURE  
BUILDS OVER THE REGION. ANOTHER TROUGH THEN DIGS ACROSS THE  
PLAINS TUESDAY NIGHT AS WAA AND ISENTROPIC LIFT ALLOWS FOR  
ANOTHER ROUND OF RAIN TO DEVELOP INTO THE DAY WEDNESDAY. AT THE  
MOMENT, PCPN WILL BE QUICK TO EXIT WEDNESDAY AFTERNOON BEFORE  
MUCH COLDER AIR ARRIVES AS A MORE POTENT COLD FRONT WILL BE  
QUICK TO MOVE THROUGH. ADDITIONAL QPF IS PROGGED BETWEEN 0.5 TO  
1.0 INCHES OF RAINFALL. HIGHS AGAIN WILL BE IN THE LOW TO MID  
50S, FOLLOWED BY THE FIRST OF MANY FREEZING NIGHTS WITH LOW  
TEMPS PLUMMETING INTO THE 20S DUE TO STRONG CAA.  
 
THE PATTERN REMAINS HIGHLY TRANSIENT AS RISING HEIGHTS THURSDAY  
QUICKLY GIVE WAY TO ANOTHER TROUGH THURSDAY NIGHT INTO FRIDAY.  
BOTH THE GFS/ECMWF SHOW AN ALBERTA CLIPPER MOVING ACROSS THE  
GREAT LAKES REGION FRIDAY MORNING THAT WILL REINFORCE TRUE  
ARCTIC COLD AIR FOR THE UPCOMING WEEKEND. ALTHOUGH THE CLIPPER  
MAY BE TOO FAR NORTH, THE NBM IS NOT PICKING UP ON THE  
POTENTIAL FOR FLURRIES OR LIGHT SNOW SHOWERS FRIDAY INTO FRIDAY  
EVENING. A TRAILING VORT MAX SHOULD SUPPORT SOME PRETTY STEEP  
LOW-LEVEL LAPSE RATES WITH THE 1000-500MB THICKNESS LINES  
FALLING BELOW 540. WITH THAT SAID, THE COLD BLAST STILL LOOKS  
FAIRLY SIGNIFICANT WITH 850 MB TEMPS AROUND -5 TO -10C OVER THE  
WEEKEND. HIGHS TEMPS IN THE 40S THURSDAY AND FRIDAY MAY STRUGGLE  
TO REACH 40 OVER THE WEEKEND FOR THIS REASON, WITH LOW TEMPS  
REMAINING WELL INTO THE 20S. WIND CHILL VALUES STILL LOOK TO  
FALL INTO THE TEENS, AND POSSIBLY THE SINGLE DIGITS.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
 
 
ISSUED AT 510 AM CST SUN DEC 15 2024  
 
IFR/LIFR CIGS WILL IMPROVE TO MVFR LATER TODAY AS THE LOW-LEVELS  
OF THE COLUMN REMAIN SATURATED. THE EXCEPTION IS KMVN, WHICH  
SHOULD REMAIN MVFR, POSSIBLY SCATTERING OUT THIS AFTERNOON.  
LINGERING AREAS OF DZ ALSO REMAIN POSSIBLE THIS MORNING, MAINLY  
THE EASTERN TERMINALS. WINDS WILL BE SOUTH BETWEEN 5-10 KTS.  
 
THE NEXT WEATHER DISTURBANCE BEGINS TO APPROACH TONIGHT WITH  
IFR/LIFR CIGS AND MVFR/IFR VSBY REDUCTIONS. NUMEROUS SHRA WILL  
SPREAD ACROSS ALL TERMINALS DURING THE OVERNIGHT HOURS INTO  
EARLY MONDAY MORNING. HAVE INCLUDED PROB30S FOR TSRA AT  
KCGI/KPAH WHERE CONDITIONS WILL BE MORE FAVORABLE. WINDS WILL BE  
SOUTH BETWEEN 8-12 KTS WITH ISOLATED GUSTS NEAR 20 KTS.  
 

 
   
PAH WATCHES/WARNINGS/ADVISORIES
 
 
IL...NONE.  
MO...NONE.  
IN...NONE.  
KY...NONE.  
 

 
 

 
 
DISCUSSION...DW  
AVIATION...DW  
 
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