037  
FXUS63 KPAH 171136  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
636 AM CDT FRI JUL 17 2026  
   
KEY MESSAGES
 
 
- DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL PERSIST INTO  
THE WEEKEND. A STRONGER GUSTY STORM CANNOT BE RULED OUT ON  
SATURDAY, ESPECIALLY IN THE NORTHEAST ACROSS SOUTHWEST  
INDIANA.  
 
- HOT AND HUMID CONDITIONS WILL CONTINUE INTO NEXT WEEK WITH  
HEAT INDEX VALUES PEAKING NEARING 105 DEGREES ON TUESDAY, WITH  
RELIEF FROM THE HEAT ARRIVING WEDNESDAY.  
 
- ANY SUSTAINED NORTHERLY FLOW (THE BEST CHANCE OF WHICH IS  
WEDNESDAY BEHIND THE COLD FRONT) COULD BRING IN UNHEALTHY AIR  
QUALITY CONDITIONS DUE TO THE NORTHWESTERN ONTARIO WILDFIRE  
SMOKE.  
 

 
   
UPDATE
 
 
ISSUED AT 637 AM CDT FRI JUL 17 2026  
 
UPDATED THE AVIATION SECTION FOR THE 12Z TAF ISSUANCE.  
 

 
   
DISCUSSION
 
 
ISSUED AT 242 AM CDT FRI JUL 17 2026  
 
BROAD UPPER-LEVEL RIDGING REMAINS ACROSS MOST OF THE COUNTRY  
TODAY. CALM WINDS AND YESTERDAY'S RAIN WILL RESULT IN SOME FOG  
FORMATION EARLY THIS MORNING. REMNANTS OF A WEAK DISTURBANCE,  
ALONG WITH PLENTY OF MOISTURE (PWS NEAR 2 INCHES) WILL HELP  
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS TODAY, MAINLY IN THE  
AFTERNOON. SOME NUISANCE FLOODING IS POSSIBLE WITH SLOW MOVING  
STORMS. HIGHER CHANCES ARE LOCATED NEAR THE EVANSVILLE TRI-STATE  
AS A FRONT IS POSITIONED NW TO SE ACROSS INDIANA. MLCAPE VALUES  
PEAK AROUND 2000-2500J/KG, WITH SHEAR OF 15-20KTS HOLDING BACK  
SEVERE WEATHER.  
 
TOMORROW, IN ADDITION TO THE PEAK HEATING AFTERNOON CONVECTIVE  
POTENTIAL, THERE IS ALSO A LATE EVENING-OVERNIGHT FRONTAL  
PASSAGE. AN SPC SLIGHT RISK EXTENDS THROUGH CENTRAL INDIANA FOR  
THIS FRONT BUT, WITH AN UNFAVORABLE OVERNIGHT TIMING, AND BEING  
FAR FROM THE LOW PRESSURE CENTER SPEEDING FROM THE GREAT LAKES  
TO QUEBEC, SEVERE WEATHER POTENTIAL IS LIMITED TO A MARGINAL  
RISK FOR STRAIGHT-LINE WINDS FOR THE EVANSVILLE TRI-STATE. SHEAR  
AND LAPSE RATES WILL BE A LITTLE MORE FAVORABLE THAN TODAY.  
TROUGHING DIGS INTO THE NORTHEAST AS THIS SYSTEM MOVES THROUGH,  
BRINGING NORTHWESTERLY FLOW ALOFT THROUGH THE QUAD STATE.  
PRECIP CHANCES ARE TRENDING HIGHER SUNDAY AS A DISTURBANCE MOVES  
AROUND THE WESTERN RIDGE.  
 
THE NBM TRENDS DRIER EARLY NEXT WEEK WITH DRY TO SLIGHT CHANCE  
POPS MONDAY AND TUESDAY. THIS MIGHT BE AN UNDERESTIMATE TUESDAY  
AS LOW PRESSURE MOVES THROUGH THE GREAT LAKES. REGARDLESS OF  
POSITIONING, NORTHEASTERN PORTIONS WOULD BE MORE FAVORED FOR  
RAIN TUESDAY VS SOUTHWESTERN AREAS. TODAY THROUGH TUESDAY, HIGHS  
SLOWLY TICK UPWARD WITH 90S BECOMING WIDESPREAD EARLY NEXT WEEK.  
HEAT INDICES AROUND 100 RISE TO 105 ON TUESDAY. COOLER AIR  
ARRIVES WEDNESDAY FOLLOWING THE TUESDAY/TUESDAY NIGHT COLD  
FRONT.  
 
ONE POTENTIAL ISSUE WOULD BE WITH ANY SUSTAINED NORTHERLY  
FLOW AS MASSIVE ACTIVE WILDFIRES IN CANADA HAVE PRODUCED  
EXTREMELY HIGH PM2.5 CONCENTRATIONS. CURRENTLY, PM2.5 READINGS  
OF 400+UG/M3 ARE LOCATED IN NORTHEASTERN MINNESOTA, 250-400 IN  
MICHIGAN/CHICAGO, AND 150-300 IN OH/PA/NJ, FOR CONTEXT, THE  
NAAQS AIR QUALITY STANDARD FOR PM2.5 IS 35.5 UG/M3 (THE  
THRESHOLD LEVEL FOR THE UNHEALTHY FOR SENSITIVE GROUPS  
CATEGORY), WHILE UNHEALTHY IS 55.5-150.4, VERY UNHEALTHY IS  
150.5-250.4, AND HAZARDOUS IS 250.5+. THOSE TRAVELING  
NORTH/NORTHEAST OF THE QUAD STATE SHOULD CHECK AIR QUALITY  
INFORMATION AND TAKE PRECAUTIONS, ESPECIALLY IF YOU HAVE A  
HEALTH CONDITION THAT PUTS YOU AT HIGHER RISK.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
 
 
ISSUED AT 637 AM CDT FRI JUL 17 2026  
 
LOCALIZED VSBY DROPS SHOULD CLEAR UP WITHIN AN HOUR. WINDS  
BECOME WESTERLY TODAY AT 5-8KTS. AFTERNOON SHOWERS AND STORMS  
ARE FORECAST, MAINLY IN THE EAST, WITH MVFR CIGS/VSBYS  
ACCOMPANYING STORMS. WINDS CALM IN THE EVENING WITH RAIN  
TAPERING OFF.  
 

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

 
 

 
 
UPDATE...ATL  
DISCUSSION...ATL  
AVIATION...ATL  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab KY Page
The Nexlab IL Page
The Nexlab IN Page
The Nexlab MO Page Main Text Page