525
FXUS63 KDVN 080255
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
955 PM CDT THU AUG 7 2025
KEY MESSAGES
- CHANCE FOR SHOWERS AND STORMS OVERNIGHT.
- HOT AND HUMID WEATHER WILL REMAIN THROUGHOUT THE AREA THROUGH
SATURDAY, WITH SOME REACHING INTO THE LOW 90S. HEAT ADVISORY
IN EFFECT FOR FRIDAY AS WELL.
- BEST CHANCE FOR PRECIPITATION RETURNS TO THE AREA SATURDAY
NIGHT THROUGH MONDAY. SEVERE WEATHER CANNOT BE RULED OUT
EITHER.
UPDATE
ISSUED AT 942 PM CDT THU AUG 7 2025
HAVE KEPT SOME LOW POPS IN OVERNIGHT AS WATER VAPOR SHOWS AN
APPROACHING VORT LOBE. AS THIS APPROACHES IT WILL INDUCE SOME
INCREASE IN LOW LEVEL WARM/MOIST ADVECTION. MID LEVEL LAPSE
RATES AND DEEP LAYER SHEAR LOOK MARGINAL, AND SOUNDINGS SHOW
RATHER TALL, SKINNY CAPE PROFILES WITH WEAKER PARCEL
ACCELERATIONS PER NORMALIZED CAPE FROM SPC MESO PAGE. THUS, I
HAVE LOW CONFIDENCE ON THE RATHER AGGRESSIVE 00Z NAMNEST
SOLUTION, WHICH WOULD SUPPORT SOME MORE ROBUST UPDRAFTS WITH
A HAIL AND GUSTY WIND THREAT AND POTENTIAL FOR HEAVY RAIN.
LEANING TOWARD A LITTLE MORE MUTED SCENARIO AS SUGGESTED BY
THE HRRR, RAP AND NSSL WRF-ARW WITH SPOTTY SHOWERS AND POSSIBLY
A FEW STORMS (WEAKER).
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 252 PM CDT THU AUG 7 2025
SATELLITE IMAGERY DEPICTS THE MCS SOUTH OF US TODAY WITH EXTENSIVE
CLOUD COVER ACROSS THE REGION. SUBSIDENCE BEHIND THE MCS SHOWS A
LARGE AREA DEVOID OF ANY SURFACE BASED CLOUDS. THIS WILL KEEP MOST
OF THE AREA DRY TODAY AS TEMPERATURES ARE TEMPERED DOWN AND THUS
INSTABILITY IS LIMITED. LATER TODAY AND INTO THE EVENING ANOTHER
WEAK WAVE IS EXPECTED TO MOVE THROUGH THE AREA. AT THE SAME TIME
H85 MOISTURE TRANSPORT WILL INCREASE. ELEVATED SHOWERS AND
STORMS MAY STILL DEVELOP LATE ACROSS THE AREA. WITH THE MCV
TRACKING MUCH FURTHER SOUTH, THE SURFACE CONVERGENCE FLOW IS A
BIT FURTHER SOUTH THAN EARLIER MODELS HAD. AS A RESULT, ELEVATED
CONVECTION MAY START TO DEVELOP THIS EVENING AGAIN AS THE H85
FLOW INCREASES. WITH THE SLIGHTLY FURTHER SOUTH FLOW, HAVE
DECIDED TO PULL CHC POPS A LITTLE FURTHER SOUTH TO NEAR THE I80
CORRIDOR THIS EVENING. OVERALL CONFIDENCE ON CONVECTION THIS
AFTERNOON IS LOW. IF IT DOES OCCUR, HEAVY RAIN WOULD LIKELY BE
THE MAIN THREAT.
INTO TOMORROW, WE SHOULD START TO SEE CLOUDS CLEARING ACROSS THE
AREA. TEMPERATURES INTO THE 90S ARE EXPECTED. THE NBM IS TOO
HIGH ON DEWPOINTS AS OF LATE, LIKELY DUE TO A BIAS THAT WAS
DEVELOPED WHEN CROPS WERE AT PEAK ET, WHICH IS NOT THE CASE
ANYMORE AS CORN AS TASSELED OUT ACROSS THE AREA. AS A RESULT F
THIS, CAPPED TDS TOMORROW IN THE MID 70S. THIS WITH THE TEMPS
YIELDS AFTERNOON HEAT INDICES IN THE LOWER 100 DEGREES. WITH NO
REAL THREAT OF OVERNIGHT CONVECTION, WENT WITH A HEAT ADVISORY
THROUGH 00Z SATURDAY.
LONG TERM /FRIDAY THROUGH THURSDAY/
ISSUED AT 252 PM CDT THU AUG 7 2025
LONG TERM DISCUSSION REMAINS VALID AS LITTLE LARGESCALE CHANGES
HAVE OCCURRED. THE MAIN THING IS THAT THE 12Z NAMNEST CAME IN
THROUGH 00Z SUNDAY. THIS GUIDANCE SHOWS A LINE OF SUPERCELLS
MOVING IN AS A MCS MOVES FROM SOUTH TO NORTH ALONG THIS LINE
INTO OUR AREA. IF THIS WERE TO COME TRUE, WE WOULD BE LOOKING AT
A TORNADO THREAT WITH STRONG WINDS AND FLASH FLOODING SATURDAY
NIGHT.
PREVIOUS DISCUSSION
ISSUED AT 235 AM CDT THU AUG 7 2025
THERMAL RIDGE CONTINUES TO SLOWLY PUSH EASTERLY THROUGH FRIDAY
AND SATURDAY, WITH UPPER LEVEL SOUTHWESTERLY FLOW KICKING IN
LATE SATURDAY THROUGH AT LEAST MONDAY. THIS FLOW WOULD FAVOR THE
CONTINUATION OF HOT AND HUMID WEATHER. WHILE WE ARE NOT
EXPECTING THE 90S TO CONTINUE BEYOND FRIDAY/SATURDAY, MID 80S
WILL REMAIN POSSIBLE INTO NEXT WEEK, WITH DEWPOINTS LARGELY
REMAINING AROUND 70. THUS, THE HUMIDITY WILL REMAIN, MAKING IT
FEEL RATHER UNPLEASANT ON THE WARMER DAYS. WITH SOUTHWESTERLY
FLOW TAKING SHAPE, ANY SYSTEM THAT DEVELOPS IN THE LEE OF THE
ROCKIES WILL TRACK RIGHT THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY. THIS PATTERN WOULD RESULT IN PERSISTENT CHANCES FOR
PRECIPITATION AS WELL. THE CONTINUOUS CHANCES FOR PRECIPITATION
IS WHAT SHOULD KEEP US IN THE 80S, BUT MAY LEAD TO FURTHER
TEMPERATURE FORECAST CHALLENGES.
SATURDAY, WE WILL SEE STRONGER SOUTHWESTERLY FLOW DEVELOP OVER THE
AREA AHEAD OF A POTENT SHORTWAVE EXPECTED TO PASS THROUGH THE AREA
THAT NIGHT THROUGH SUNDAY. AHEAD OF THAT WAVE, WE WILL SEE A
WEAK WAVES LEADING THE PARENT WAVE, WHICH WILL PROMOTE CHANCES
FOR SHOWERS AND STORMS THAT AFTERNOON AND NIGHT. OVERALL, THIS
WILL OCCUR WHEN WE HAVE RELATIVELY LOW STEERING FLOW OVER THE
AREA, WHICH SHOULD RESULT IN SLOWER STORM MOTION. THUS, SLOW
MOVING STORMS MAY BE SEEN ON SATURDAY, WHICH CAN LEAD TO LOCALLY
HEAVY RAINFALL FOR SOME. PWATS WILL APPROACH 1.75-2.00" THROUGH
THE AFTERNOON ON SATURDAY, FURTHER FAVORING HEAVY RAINFALL
WHERE THE STORMS DEVELOP. THUS, THIS WOULD RESULT IN A LOCALIZED
FLASH FLOOD THREAT. CONFIDENCE REMAINS LOW ON THE COVERAGE, AS
WE ARE NOT EXPECTING A WIDESPREAD WASHOUT. THUS, A MARGINAL RISK
(LEVEL 1/4) FOR EXCESSIVE RAINFALL AND FLASH FLOODING IS
OUTLOOKED FOR THE AREA. STRONG TO SEVERE STORMS CANNOT BE RULED
OUT EITHER, WITH CIPS ANALOG GUIDANCE CONTINUING TO INDICATE THE
POTENTIAL. SPC HAS ALSO OUTLOOKED THE AREA IN A MARGINAL RISK
(LEVEL 1/5) FOR SATURDAY. THIS SEEMS TO LARGELY BE FOCUSED WITH
THE BETTER FORCING ASSOCIATED WITH THE STRONGER WAVE SATURDAY
NIGHT. WE WILL ALSO SEE BETTER MOISTURE MOVING IN SATURDAY NIGHT
INTO SUNDAY, WITH PWATS BETWEEN 2.00-2.25". THIS IS
UNSEASONABLY HIGH AND WOULD FAVOR HEAVY RAINFALL RATES WITH ANY
STORM. THUS, THERE WILL BE THE POTENTIAL FOR SEVERAL HAZARDS
SATURDAY THROUGH SUNDAY WHICH WE WILL CONTINUE TO MONITOR AND
UPDATE ACCORDINGLY AS MORE GUIDANCE COMES IN.
SUNDAY AND BEYOND, WE WILL CONTINUE TO SEE SHORTWAVES PASSING
THROUGH THE AREA NEAR-DAILY. THUS, WE ARE LOOKING AT THE POTENTIAL
FOR DAILY CHANCES OF PRECIPITATION OVER MUCH OF THE AREA THROUGH AT
LEAST TUESDAY. AT THIS TIME, IT DOESN'T SEEM TO BE A COMPLETE
WASHOUT THROUGH THAT TIMEFRAME. RATHER, THERE SHOULD BE PLENTY OF
DRY TIME BETWEEN PASSING SYSTEMS. WITH THIS PATTERN IN PLACE, WE
WILL REMAIN WARM AND HUMID THROUGH THE FIRST HALF OF NEXT WEEK. TOO
SOON TO DETERMINE ANY SEVERE THREAT WITH THESE PASSING WAVES.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 645 PM CDT THU AUG 7 2025
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE TAF CYCLE. THERE
IS A LOW CHANCE (<20%) FOR A SHRA/TSRA 06Z-12Z, BUT BOTH COVERAGE
AND CONFIDENCE ON IMPACTS AT TERMINALS IS TOO LOW FOR ANY MENTION
AT THIS TIME ALTHOUGH THIS POTENTIAL WILL CONTINUE TO BE MONITORED.
S/SE WINDS REMAIN AT OR BELOW 10 KTS TONIGHT, BUT THEN TURN GUSTY
AT 15-25 KTS ON FRIDAY.
DVN WATCHES/WARNINGS/ADVISORIES
IA...HEAT ADVISORY FROM 1 PM TO 7 PM CDT FRIDAY FOR IAZ051>054-
063>068-076>078-087>089-098-099.
IL...HEAT ADVISORY FROM 1 PM TO 7 PM CDT FRIDAY FOR ILZ001-002-007-
009-015>018-024>026-034-035.
MO...HEAT ADVISORY FROM 1 PM TO 7 PM CDT FRIDAY FOR MOZ009-010.
UPDATE...MCCLURE
SHORT TERM...GIBBS
LONG TERM...GUNKEL
AVIATION...MCCLURE
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