765  
FXUS63 KPAH 201745  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
1245 PM CDT MON JUL 20 2026  
   
KEY MESSAGES
 
 
- DAILY CHANCES OF SHOWERS AND THUNDERSTORMS CONTINUE INTO  
TUESDAY. A FEW ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE  
BETWEEN 12-7PM WHEN RAIN CHANCES PEAK AT 40-60%. LOCALIZED  
FLASH FLOODING ISSUES ARE ALSO POSSIBLE WITH HEAVY RAINFALL  
RATES.  
 
- A HEAT ADVISORY AND EXTREME HEAT WARNING ARE BOTH NOW IN  
EFFECT THROUGH TUESDAY EVENING. HEAT INDEX VALUES OF 100 TO  
106 ARE EXPECTED TODAY AND 110 TO 116 ON TUESDAY.  
 
- UNHEALTHY AIR QUALITY CONDITIONS FROM THE ONTARIO WILDFIRE  
SMOKE WILL CONTINUE THROUGH TUESDAY MAINLY ACROSS PORTIONS OF  
SOUTHERN ILLINOIS AND SOUTHWEST INDIANA.  
 

 
   
DISCUSSION
 
 
ISSUED AT 1244 PM CDT MON JUL 20 2026  
 
WEAK NORTHWEST FLOW ALOFT AND A SFC BOUNDARY WILL ALLOW FOR ISOLATED  
RAIN CHANCES THIS AFTERNOON, ESPECIALLY ACROSS SOUTHEAST MISSOURI.  
THE BOUNDARY LIFTS NORTH OVERNIGHT WITH SOME IMPROVEMENT TO THE  
UNHEALTHY AIR QUALITY CONDITIONS ACROSS PORTIONS OF SOUTHERN  
ILLINOIS AND SOUTHWEST INDIANA ON TUESDAY. HOWEVER, A STRONG  
COLD FRONT WILL BEGIN TO APPROACH THE FA FROM THE NORTHWEST WITH  
INCREASING SHEAR FROM A 40-50 KT JET AT 700-500 MB. WHILE MOST  
OF THE CAMS SHOW THE BULK OF SCATTERED CONVECTION OCCURRING  
DURING THE AFTERNOON HOURS, THE FV3/ARW HAVE A DECAYING COMPLEX  
OF STORMS MOVING ACROSS SOUTHWEST INDIANA AFTER 12Z. MEANWHILE,  
THE HRRR/NSSL SHOW SCATTERED DEVELOPMENT MAINLY SOUTH OF THE  
OHIO CONFINED TO THE AFTERNOON HOURS. DESPITE THE UNCERTAINTY,  
THE RISK FOR ISOLATED STRONG TO SEVERE STORMS WILL BE THE  
GREATEST BETWEEN 12-7PM WHEN 4000 TO 5000 J/KG OF MLCAPE IS  
PROGGED BY THE RAP13 ALONG WITH 7.0 C/KM SFC-3KM LAPSE RATE.  
ALTHOUGH THE BEST SHEAR WILL BE LAGGING BEHIND THE FRONT, A  
ROBUST THETA-E DIFFERENCE OF 30-40K WILL FAVOR 60-70 MPH  
DAMAGING WIND GUSTS AS THE MAIN HAZARD OF CONCERN. TORRENTIAL  
DOWNPOURS WILL ALSO BE CAPABLE OF CAUSING LOCALIZED FLASH  
FLOODING ISSUES WITH RUNOFF ON ROADWAYS.  
 
A HEAT ADVISORY AND EXTREME HEAT WARNING ARE NOW IN EFFECT THROUGH  
TUESDAY AS HEAT INDEX VALUES BETWEEN 110 TO 116 ARE PROGGED FOR  
TOMORROW. HOWEVER, LOCATIONS ALONG I-64 ARE ONLY UNDER A HEAT  
ADVISORY AS THE EARLIER TIMING OF STORMS WILL HELP TO KEEP HEAT  
INDICES A BIT COOLER IN THE 105 TO 109 RANGE. HIGH TEMPERATURES  
IN THE LOW TO MID 90S ARE EXPECTED OVER MOST OF THE FA SETTING  
THE STAGE FOR THE HOTTEST DAY OF THE WEEK. THE AIR QUALITY WILL  
ALSO STILL BE UNHEALTHY ACROSS PORTIONS OF SOUTHERN ILLINOIS AND  
SOUTHWEST INDIANA DUE TO THE WILDFIRES IN CANADA. TEMPERATURES  
WILL THEN BE 10 DEGREES COOLER BEHIND THE FRONT ON WEDNESDAY  
WITH HIGHS ONLY IN THE LOW TO MID 80S. HUMIDITY LEVELS WILL  
ALSO BE SIGNIFICANTLY LOWER WITH DEWPOINTS DIPPING DOWN INTO THE  
60S AND 50S. RAIN CHANCES RETURN ON FRIDAY AS A SHORTWAVE MOVES  
THROUGH, FOLLOWED BY A SIGNIFICANT WARMING TREND WITH AN  
INCREASE IN HUMIDITY OVER THE WEEKEND AS THE EASTERN EXTENT OF A  
597 DM RIDGE OVER THE SOUTHERN PLAINS BUILDS IN. TEMPERATURES BY  
EARLY NEXT WEEK WILL ONCE AGAIN REACH THE 90S.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
 
 
ISSUED AT 1244 PM CDT MON JUL 20 2026  
 
LINGERING POCKETS OF MVFR CIGS WILL SCATTER OUT TO VFR THIS  
AFTERNOON ACROSS THE ENTIRE REGION. THERE IS A 20% CHANCE OF AN  
ISOLATED THUNDERSHOWER, ESPECIALLY AT KCGI, BUT COVERAGE IS TOO  
LOW TO INCLUDE TAF MENTION. RAIN CHANCES INCREASE TO 30% AT  
KEVV/KOWB TUESDAY MORNING AS THERE IS UNCERTAINTY IN A DECAYING  
COMPLEX OF STORMS. LIGHT WINDS TONIGHT TURN WEST-SOUTHWEST  
BETWEEN 6-11 KTS TUESDAY MORNING WITH ISOLATED GUSTS AROUND 20  
KTS.  
 

 
   
PAH WATCHES/WARNINGS/ADVISORIES
 
 
IL...HEAT ADVISORY UNTIL 11 AM CDT TUESDAY FOR ILZ075-080>082-  
084>094.  
EXTREME HEAT WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR ILZ075-  
080>094.  
HEAT ADVISORY FROM 11 AM TO 7 PM CDT TUESDAY FOR ILZ076>078.  
MO...HEAT ADVISORY UNTIL 11 AM CDT TUESDAY FOR MOZ076-086-087-100-  
107>112-114.  
EXTREME HEAT WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR MOZ076-  
086-087-100-107>112-114.  
IN...EXTREME HEAT WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR  
INZ085>088.  
HEAT ADVISORY FROM 11 AM CDT /NOON EDT/ TO 7 PM CDT /8 PM EDT/  
TUESDAY FOR INZ081-082.  
AIR QUALITY ALERT UNTIL 11 PM CDT /MIDNIGHT EDT/ THIS EVENING  
FOR INZ081-082-085>088.  
KY...HEAT ADVISORY UNTIL 11 AM CDT TUESDAY FOR KYZ001>017-021-022.  
EXTREME HEAT WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR  
KYZ001>022.  
 

 
 

 
 
DISCUSSION...DW  
AVIATION...DW  
 
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