706
FXUS63 KDVN 310601
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
101 AM CDT FRI JUL 31 2026
KEY MESSAGES
- WIDESPREAD SOAKING RAINFALL FRIDAY THROUGH SATURDAY WITH AN
80-90% CHANCE OF RAINFALL AMOUNTS OVER 1 INCH AND A 40-70%
CHANCE OF RAINFALL AMOUNTS OVER 2 INCHES. SLIGHT RISK (LEVEL 2
OF 4) FOR LOCALIZED FLASH FLOODING.
- CONDITIONAL RISK (LEVEL 1 OF 5) FOR SEVERE THUNDERSTORMS
FRIDAY AFTERNOON INTO EVENING FOR PARTS OF SOUTHEAST IOWA,
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS.
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 1220 PM CDT THU JUL 30 2026
WIDESPREAD RAINFALL FRIDAY-SATURDAY
A MID/UPPER LEVEL SHORTWAVE CURRENTLY OVER THE DAKOTAS WILL
DEEPEN AND DIG SLOWLY SOUTHEAST ACROSS THE MIDWEST DURING
THE PERIOD. RAMPING LOW LEVEL MOISTURE TRANSPORT AND LIFT
WILL SUPPORT PERIODIC ROUNDS OF SHOWERS AND STORMS ARRIVING
AS EARLY AS LATE TONIGHT, AND CONTINUING INTO SATURDAY
AFTERNOON BEFORE TAPERING OFF AS THE SYSTEM BEGINS TO DEPART.
IT WON'T BE A COMPLETE WASHOUT WITH ALSO PERIODS WHERE IT
WON'T BE RAINING, BUT THE RAINFALL WILL BE A SOAKING ONE AND
GENERALLY MUCH NEEDED/BENEFICIAL WITH IT BEING DRY OF LATE AND
IN FACT SOME AREAS IN ABNORMALLY DRY (D0) CONDITIONS PER THE
LATEST DROUGHT MONITOR. NBM PROBABILITIES FOR OVER 1 INCH
OF RAIN ARE 80-90% FOR THE 48 HOUR PERIOD ENDING 00Z SUNDAY,
WITH THE PROBABILITIES FOR OVER 2 INCHES OF RAIN AT 40-70%.
DEEP ATMOSPHERIC MOISTURE (PWATS AROUND 2 INCHES) COMBINED WITH
SLOW STORM MOTIONS AND THE POTENTIAL FOR REPEATED ACTIVITY WILL
FOSTER THE POTENTIAL FOR LOCALIZED FLOODING. 12Z HREF 24 HR
LPMM (LOCALIZED PROBABILITY MATCHED MEAN) GUIDANCE SUGGESTS
POTENTIAL FOR 3+ INCH AMOUNTS WHICH IF WOULD OCCUR OVER AN
URBAN AREA ESPECIALLY COULD RESULT IN LOCALIZED FLOODING (LEVEL
2 OF 4 RISK FOR EXCESSIVE RAINFALL). 3-HOUR FLASH FLOOD GUIDANCE
IS GENERALLY OVER 2 TO 3 INCHES. CROPS IN RURAL AREAS BEING
WELL MATURED SHOULD AID IN INFILTRATION CAPACITY, THEREBY
HELPING TO MITIGATE THIS POTENTIAL SOME IN RURAL LOCATIONS.
BUT, THIS COULD CHANGE WITH ANY INTENSE RAINFALL RATES (2+"/
HOUR). OVERALL, THE HIGHEST RATES SHOULD BE WITH STORMS AND
GENERALLY 1-2"/HR AND OUTSIDE OF STORMS IN THE SHOWERS AND
AREAS OF MORE WIDESPREAD RAIN THE RATES SHOULD BE AN INCH OR
LESS.
CONDITIONAL RISK FOR SEVERE STORMS FRIDAY AFTERNOON/EVENING
THERE IS A LEVEL 1 OUT OF 4 RISK FOR SEVERE STORMS FRIDAY PM,
MAINLY IN PARTS OF THE AREA SOUTH OF I-80. CONFIDENCE IS
LOW RIGHT NOW DUE TO UNCERTAINTY IN CLOUD COVER/INSTABILITY.
IF WE CAN SEE SOME CLEARING AND SURFACE HEATING TAKE PLACE
FRIDAY AFTERNOON AHEAD OF THE SURFACE LOW AND COLD FRONT THEN
WE COULD SEE SOME POTENTIAL FOR ISOLATED/FEW STRONG TO SEVERE
THUNDERSTORMS. THE PRIMARY CONCERN WOULD BE BRIEF TORNADOES
WITH ANY LOW TOPPED SUPERCELLS, OR LANDSPOUTS WITH ANY WEAKER
CONVECTION SHOULD ANY SURFACE STRETCHING OCCUR AMIDST
FAVORABLY LOW LCLS IN THE PRESENCE OF ANY LOW LEVEL HELICITY
AND CAPE. TIMING APPEARS TO BE ROUGHLY 3 PM TO 9 PM.
WHILE HAIL AND WINDS ARE ALSO POSSIBLE, THESE THREATS WOULD
APPEAR TO BE SECONDARY AND LOWER WITH HIGH MOISTURE AND WARM
TEMPS ALOFT LIMITING HAIL PRODUCTION WHILE WIND THREAT WOULD
LIKELY REQUIRE SOME ORGANIZED CONVECTION.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ISSUED AT 1220 PM CDT THU JUL 30 2026
AS THE SHORTWAVE DEPARTS SATURDAY, A TIGHT PRESSURE GRADIENT
WILL CAUSE GUSTY WINDS UP TO 30 MPH FROM THE N/NE THROUGH THE
EVENING.
SUNDAY THROUGH THURSDAY, FOLLOWING THE PASSAGE OF THE
SHORTWAVE, A RIDGE WILL BRIEFLY TAKE HOLD OVER THE REGION BEFORE
THE FLOW ALOFT BECOMES MORE ZONAL. OF NOTE IS A DEEP TROUGH
OVER SOUTHERN CANADA THROUGH MUCH OF NEXT WEEK, WHICH WILL SEND
IMPULSES THROUGH THE FLOW AND PROVIDE PERIODIC CHANCES FOR RAINFALL.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1258 AM CDT FRI JUL 31 2026
GRADUALLY DECREASING FLIGHT CONDITIONS FROM VFR TO PREVAILING MVFR
ARE EXPECTED THROUGH THE TAF PERIOD AS A STORM SYSTEM MOVES THROUGH
THE AREA WITH SCATTERED SHOWERS AND STORMS. CIGS WILL LOWER OVER THE
NEXT SEVERAL HOURS FROM WEST TO EAST, REACHING MVFR AS EARLY AS
31/07Z AT CID TO 31/16Z AT DBQ. IFR CIGS ARE LIKELY (60-80%) AFTER
31/18Z AND WILL CONTINUE PAST THE END OF THE TAF PERIOD. AN INITIAL
CLUSTER OF SHOWERS WILL MOVE THROUGH CID IN THE 31/07-10Z WINDOW
WITH OBSERVED DROPS TO 2SM OR LOWER IN CENTRAL IOWA. BY 31/12Z, THE
MAIN LINE OF SHOWERS AND STORMS WILL REACH WESTERN TERMINALS AND
MAKE ITS WAY EASTWARD THROUGH 31/17Z, AFTER WHICH SCATTERED SHOWERS
(MLI/DBQ) AND THUNDERSTORMS (CID/BRL) WILL BE POSSIBLE WITH IFR
CIGS. WINDS WILL BE SOUTHEASTERLY 8-12 KTS WITH GUSTS TO 25 KTS
POSSIBLE FOR MLI/BRL AS THE STORM SYSTEM STRENGTHENS.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...MCCLURE
LONG TERM...ELLINGWORTH/MCCLURE
AVIATION...ELLINGWORTH
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