726
FXUS63 KDVN 240635
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
135 AM CDT FRI JUL 24 2026
KEY MESSAGES
- HEAT AND HUMIDITY RETURNS THIS WEEKEND AND INTO EARLY NEXT
WEEK. HEAT INDICES AROUND OR EXCEEDING 100 DEGREES ARE
EXPECTED SUNDAY AND MONDAY. AN EXTREME HEAT WATCH HAS BEEN
ISSUED FOR SUNDAY INTO MONDAY.
- THUNDERSTORMS ARE POSSIBLE SUNDAY AND MONDAY THAT MAY BE
STRONG TO SEVERE.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 129 AM CDT FRI JUL 24 2026
FORCING ALOFT WILL BRING A BAND OF SPRINKLES AND SHOWERS
THROUGH THE CENTRAL PARTS OF THE AREA THROUGH MID-DAY. PROGGED
SOUNDINGS OF THE ATMOSPHERE CONTINUE TO SHOW RESPECTABLE AMOUNTS
OF DRY AIR. THE COMBINATION OF THE DRY AIR AND WEAKENING
FORCING WILL RESULT IN A GRADUAL DECAY OF THE LIGHT
PRECIPITATION THROUGH THE MORNING.
TONIGHT RETURN FLOW DEVELOPS WHICH WILL CAUSE DEW POINTS TO SLOWLY
RISE THROUGH THE NIGHT. ANOTHER PASSING UPPER LEVEL DISTURBANCE IN
THE WARM ADVECTION ALOFT MAY GENERATE SOME ISOLATED TO LOW END
SCATTERED (10-30%) SHOWERS DURING THE NIGHT. A ROGUE THUNDERSTORM
CANNOT BE RULED OUT.
LONG TERM /SATURDAY THROUGH THURSDAY/
ISSUED AT 129 AM CDT FRI JUL 24 2026
SATURDAY THROUGH MONDAY
ASSESSMENT...A CERTAINTY (>98%) OF HIGH HEAT AND HUMIDITY. LOW
(<20%) CONFIDENCE REGARDING POSSIBLE STORMS
HEAT AND HUMIDITY WILL SURGE INTO THE AREA AS THE HEAT DOME BUILDS
NORTH INTO THE PLAINS. TAKING INTO ACCOUNT THE WARM AND MOIST BIAS
OF THE MODEL CONSENSUS, DEW POINTS WILL SLOWLY CLIMB THROUGH THE 60S
ON SATURDAY WITH LOW AND MID 70S DEW POINTS SUNDAY AND MONDAY. WITH
PROGGED TEMPERATURES EVENTUALLY REACHING 90 TO 95 SUNDAY/MONDAY,
HEAT INDICES AT OR EXCEEDING 100 ARE EXPECTED SUNDAY INTO MONDAY.
THE WILD CARD IN ALL THIS WILL BE THE ORGANIZED NOCTURNAL STORMS
MOVING AROUND THE EDGE OF THE HEAT DOME. THE ACTIVITY WILL MOVE
ACROSS MINNESOTA INTO WISCONSIN AND EVENTUALLY TURN SOUTH TOWARD
ILLINOIS. WHEN/WHERE THEY TURN SOUTH WILL BE THE KEY TO WHETHER OR
NOT PARTS OF THE AREA GET SIDE-SWIPED BY THE STORM COMPLEXES AND
POTENTIAL DIURNAL DEVELOPMENT IN THE AFTERNOON. WE'LL BE DEALING
WITH NON-LINEAR PROCESSES WHICH ARE NOT HANDLED WELL BY THE MODELS.
STORM DEVELOPMENT FRIDAY NIGHT INTO SATURDAY WILL INFLUENCE THE
DEVELOPMENT OF STORMS THE FOLLOWING NIGHT ET CETERA.
THUS WHILE THE POTENTIAL FOR STORMS IS LOW, IF STORMS OCCUR THE
IMPACTS COULD BE SIGNIFICANT; ONE IS STRONG TO SEVERE STORMS, THE
OTHER IS POTENTIALLY MUCH LOWER TEMPERATURES FOR PARTS OF THE AREA
SUNDAY AND MONDAY.
GIVEN THIS WE WILL BE HOISTING AN EXCESSIVE HEAT WATCH FOR AREAS
ALONG AND WEST OF THE MISSISSIPPI AND WEST CENTRAL ILLINOIS. THESE
HEADLINES MAY OR MAY NOT NEED TO BE EXPANDED FURTHER EAST OF THE
MISSISSIPPI.
MONDAY NIGHT THROUGH THURSDAY
ASSESSMENT...HIGH (>80%) CONFIDENCE OF CONTINUED HEAT AND HUMIDITY
STARTING MONDAY NIGHT AND CONTINUING THE REMAINDER OF THE WEEK, THE
HEAT DOME AND ASSOCIATED UPPER LEVEL RIDGE SLOWLY DE-AMPLIFIES. A
WEAK SURFACE HIGH WILL BRIEFLY TURN WINDS AROUND TO THE NORTH AND
EAST MONDAY NIGHT THROUGH WEDNESDAY THAT WILL SLIGHTLY LOWER
TEMPERATURES. HOWEVER, HEAT INDICES IN THE MID AND UPPER 90S WILL
STILL BE COMMON.
WEDNESDAY NIGHT INTO THURSDAY THE VARIOUS MODELS BRING A VERY WEAK
DISTURBANCE THROUGH THE AREA. GIVEN THE WEAK FORCING THIS
DISTURBANCE MAY OR MAY NOT PRODUCE SOME CONVECTION. SEVERAL MODEL
SOLUTIONS ARE DRY BUT SOME OF THEIR ENSEMBLE MEMBERS GENERATE SOME
LIGHT QPF. THUS WHILE THE MODEL CONSENSUS HAS A 20 PERCENT CHANCE OF
RAIN, MOST OF THE AREA WILL REMAIN DRY.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1214 AM CDT FRI JUL 24 2026
PASSING UPPER LEVEL DISTURBANCE TO BRING SPRINKLES AND SOME
ISOLATED SHRA THROUGH 15Z/24. SOUTHERLY RETURN FLOW SLOWLY
DEVELOPS THIS AFTERNOON AND CONTINUES AFTER 00Z/25. AFTER 00Z/25
WARM ADVECTION MAY RESULT IN SOME MORE ISOLATED SHRA.
DVN WATCHES/WARNINGS/ADVISORIES
IA...EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR IAZ040>042-051>054-063>068-076>078-087>089-
098-099.
IL...EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR ILZ015-024>026-034-035.
MO...EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR MOZ009-010.
SHORT TERM...08
LONG TERM...08
AVIATION...08
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