947
FXUS63 KDVN 010547
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1247 AM CDT WED JUL 1 2026
..06Z AVIATION UPDATE
KEY MESSAGES
- EXTREME HEAT WARNING CONTINUES THROUGH THURSDAY EVENING FOR
MUCH OF THE AREA WITH ONGOING PROLONGED PERIOD OF HOT AND VERY
HUMID CONDITIONS. DAILY PEAK HEAT INDEX VALUES OF 100 TO 110
AND NIGHTTIME LOW TEMPERATURES ONLY DROPPING INTO THE MID TO
UPPER 70S.
- HUMID CONDITIONS WILL CONTINUES INTO THE HOLIDAY WEEKEND.
CLOUD COVER AND SLOWLY INCREASING STORM CHANCES WILL HELP TO
LOWER TEMPERATURES. STORMS WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAINFALL
SHORT TERM /THROUGH THURSDAY/
ISSUED AT 158 PM CDT TUE JUN 30 2026
EXTREME HEAT AND HUMIDITY WILL CONTINUE BUT ALL MODELS ARE SHOWING
THE GRADUAL EASTWARD SHIFT TO THE HEAT DOME. AS IT DOES, THE
NOCTURNAL CONVECTION WILL MOVE CLOSER TO THE AREA.
CONVECTION IN THE PLAINS IS IN A CHANNEL OF MOISTURE THAN HAS A
TROPICAL CONNECTION THROUGH WEST TEXAS AND MEXICO. THUS THROUGH THE
LATE AFTERNOON AND EVENING HOURS NO RAIN IS EXPECTED.
AFTER MIDNIGHT THE QUESTION BECOMES WILL ANY NOCTURNAL CONVECTION
INVADE PARTS OF THE AREA. MOST VERY SHORT TERM MODELS SUGGEST NO
RAIN. THE EXCEPTION IS THE NAMNEST WHICH BRINGS SOME NOCTURNAL
SHOWERS INTO THE AREA AFTER MIDNIGHT. IF THIS SOLUTION IS CORRECT
THEN AREAS IN THE HIGHWAY 20 CORRIDOR WEST OF DUBUQUE 'MIGHT' SEE
SOME RAIN. HOWEVER, THE OVERALL PROBABILITY IS LOW AT 15-25 PERCENT.
WEDNESDAY WILL BE A REPEAT OF TUESDAY WITH EXTREME HEAT AND HUMIDITY
AREA-WIDE. HOWEVER, WITH THE PREVIOUS NIGHTS CONVECTION BEING A BIT
CLOSER, CLOUD COVER MAY HELP TO HOLD DOWN TEMPERATURES A LITTLE.
HEAT INDICES STILL LOOK TO BE IN THE 100 TO 110 RANGE WITH IT BEING
DAY THREE OF THE HEAT.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
ISSUED AT 158 PM CDT TUE JUN 30 2026
WHEN STORMS DO RETURN TO THE AREA, HIGH MOISTURE LEVELS IN THE
ATMOSPHERE BRINGS THE RISK OF HEAVY RAINFALL.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT
ASSESSMENT...A CERTAINTY (>98%) THAT HUMID CONDITIONS CONTINUE.
LOW (<25%) CONFIDENCE REGARDING THE TIMING OF EVENTUAL CONVECTION.
STARTING WEDNESDAY NIGHT AND CONTINUING THROUGH FRIDAY NIGHT THE
HEAT DOME WILL GRADUALLY MOVE TOWARD THE EAST COAST AND THE UPPER
RIDGE BEGINS TO FLATTEN. AS IT DOES, DISTURBANCES MOVING AROUND THE
EDGE OF THE HEAT DOME WILL BRING THE POTENTIAL FOR STORMS. HOWEVER,
EACH ROUND OF STORMS WILL INFLUENCE WHERE THE SUBSEQUENT ROUND OF
STORMS WILL INITIATE AND EVENTUALLY MOVE.
WEDNESDAY EVENING HAS A HIGH (>80%) PROBABILITY OF BEING DRY ACROSS
THE AREA. NOCTURNAL STORMS LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING LOOK TO IMPACT AREAS NORTH OF HIGHWAY 30. RESIDUAL CLOUD
COVER FROM THE NOCTURNAL CONVECTION AND EXPECTED NEW CONVECTION
THURSDAY AFTERNOON WILL LIKELY TEMPER TEMPERATURES AND MAY HOLD HEAT
INDICES IN THE 95 TO 100 RANGE. HOWEVER, IF THE CONVECTION IS
FURTHER NORTH THAN EXPECTED THEN HEAT INDICES MAY AGAIN EXCEED 100.
THE EXPECTED CONVECTION THURSDAY NIGHT INTO FRIDAY HAS THE POTENTIAL
TO BE MORE INTERESTING.
THE HEAT DOME WILL HAVE MOVED FURTHER TO THE EAST AND THERE IS A
RESPECTABLE UPPER LEVEL DISTURBANCE PROGGED TO MOVE OUT OF THE
ROCKIES AND TOWARD THE MIDWEST. THE SIGNALS ARE THERE FOR A STORM
COMPLEX TO DEVELOP IN THE PLAINS THAT MOVES EAST OVERNIGHT. THE
COMPLEX WILL BE IN A WEAKENING PHASE AS IT ARRIVES IN EASTERN IOWA
IN THE PRE-DAWN HOURS BUT MAY BE CAPABLE OF SOME ISOLATED SEVERE
STORMS. IF SEVERE STORMS WOULD OCCUR, DAMAGING WINDS WOULD BE THE
PRIMARY RISK.
BOUNDARIES AND CLOUD COVER LEFT OVER FROM THE THURSDAY NIGHT STORMS
WILL HELP TO HOLD DOWN TEMPERATURES AND ALSO PROVIDE BOUNDARIES FOR
DIURNAL CONVECTION FRIDAY AFTERNOON THAT WILL CONTINUE INTO FRIDAY
NIGHT.
PRIOR TO FRIDAY, AREAL COVERAGE OF ANY STORMS WILL BE LOW (15-30%).
STARTING FRIDAY, CHANCES WILL INCREASE TO 30-50% BUT NOT ALL AREAS
WILL SEE RAIN.
SATURDAY THROUGH TUESDAY
ASSESSMENT...A CERTAINTY (>95%) THAT HUMID CONDITIONS WILL CONTINUE.
LOW (20-30%) CONFIDENCE ON STORM TIMING AND AREAL COVERAGE.
ANOTHER DISTURBANCE MOVING THROUGH THE MIDWEST SATURDAY AND SATURDAY
NIGHT CURRENTLY LOOKS TO HAVE THE BETTER CHANCES TO PRODUCE RAIN.
THIS MAY OR MAY NOT BE IN THE FORM OF AN ORGANIZED STORM COMPLEX.
RIGHT NOW, THE MODEL CONSENSUS HAS RAIN CHANCES AT 30-55% WITH THE
BETTER CHANCES ALONG/NORTH OF I-80.
STARTING SUNDAY, THERE ARE ADDITIONAL UPPER LEVEL DISTURBANCE
PROGGED TO MOVE THROUGH THE AREA EACH DAY. HOWEVER, THERE ARE TIMING
DIFFERENCES. THE MAIN MESSAGE IS THAT WHILE THERE ARE RAIN CHANCES
EACH DAY, NOT EVERYONE WILL SEE RAIN. ADDITIONALLY, AREAL COVERAGE
OF ANY RAIN IS LOW AT 15 TO 25 PERCENT.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1240 AM CDT WED JUL 1 2026
GENERALLY A VFR TAF FCST AS LONG AS THE STORMS STAY WEST AND
NORTH OF THE TAF SITES, WHICH THE MAJORITY OF CAMS AND
DETERMINISTICS SUGGEST. BUT THEY MAY GET INTO THE VCNTY OF DBQ
AND POSSIBLY CID TOWARD THE END OF THE TAF CYCLE. OTHERWISE,
DON'T EXPECT MVFR BKN CU TO DEVELOP ACRS THE CID AND DBQ SITES
LIKE YESTERDAY, ALTHOUGH THERE STILL MAY BE SOME SCT COVERAGE.
SOUTH TO SOUTHWESTERLY SFC WINDS TO CONTINUE BUT MAY NOT BE AS
QUITE GUSTY ON WED AS THE PAST FEW DAYS. WITH THE LIGHTER WINDS
CURRENTLY ONGOING OVERNIGHT, HAVE ADDED BACK THE LLVL WIND SHEAR
WITH SOUTHWESTERLY 2K FT AGL LLJ OF 35-40 KTS INTO WED MORNING.
DVN WATCHES/WARNINGS/ADVISORIES
IA...EXTREME HEAT WARNING UNTIL 10 PM CDT THIS EVENING FOR
IAZ040>042-051>054.
EXTREME HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR IAZ063>068-
076>078-087>089-098-099.
IL...EXTREME HEAT WARNING UNTIL 10 PM CDT THIS EVENING FOR ILZ001-
002-007.
EXTREME HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR ILZ009-
015>018-024>026-034-035.
MO...EXTREME HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR MOZ009-010.
SHORT TERM...08
LONG TERM...08
AVIATION...12
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