360
FXUS63 KDVN 280522
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1222 AM CDT TUE JUL 28 2026
KEY MESSAGES
- OPPRESSIVELY HOT AND HUMID THROUGH THIS EVENING, WITH HEAT
INDICES IN MANY LOCATIONS PEAKING AROUND 105-115 DEGREES.
- THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON INTO THE EVENING,
THOUGH THERE REMAINS SOME UNCERTAINTY DUE TO CAPPING
INVERSIONS. SOME OF THESE STORMS MAY BE STRONG TO SEVERE WITH
DAMAGING WINDS THE MAIN HAZARD IF WELL-ORGANIZED CONVECTION
DEVELOPS. A SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE WEATHER
REMAINS FOR AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER.
- SOME MID-WEEK RELIEF FROM THE HEAT AND HUMIDITY COMES BEHIND
A COLD FRONT TONIGHT, ALTHOUGH SMOKE FROM NORTHWEST U.S. AND
CANADIAN FIRES MAY SPREAD OVER THE AREA THAT COULD CONTINUE
THROUGH TUESDAY.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 207 PM CDT MON JUL 27 2026
MID-DAY UPPER AIR FLIGHT SHOWS SEVERAL SMALL CAPPING INVERSIONS
ALOFT. THESE CAPS, ALONG WITH LIKELY SUBSIDENCE BEHIND THE MCS
ALONG LAKE MICHIGAN, ARE ACTING TO SUPPRESS CONVECTIVE
DEVELOPMENT ACROSS THE AREA SO FAR.
PEAK HEATING ALONG ANY BOUNDARIES OR THETA-E GRADIENTS SHOULD
FORCE ISOLATED TO LOW-END SCATTERED (20-40%) COVERAGE OF
DIURNAL STORMS ALONG/AHEAD OF THE COLD FRONT. THESE STORMS WILL
QUICKLY DISSIPATE WITH SUNSET, LEAVING THE REMAINDER OF THE
OVERNIGHT HOURS MUGGY BUT DRY.
THE QUESTION AFTER MIDNIGHT IS WILL ANY SMOKE APPROACH THE SURFACE
DUE TO POST-FRONTAL MIXING OR REMAIN ALOFT. SOME SOLUTIONS
SUGGEST YES WHILE OTHERS SAY NO. SO, WE WILL DO A MIDDLE OF THE
ROAD SOLUTION AND DO A PARTIAL MIX-DOWN WITH THE IDEA SOME
AREAS MAY EXPERIENCE SOME SMOKE FOR A FEW HOURS BUT A MAJORITY
OF IT REMAINS ALOFT.
TUESDAY WILL BE A BIT COOLER AND DEFINITELY LESS HUMID, WITH
DEW POINTS IN THE UPPER 60S TO LOWER 70S. NET RESULT WILL BE
PEAK AFTERNOON HEAT INDICES IN THE UPPER 80S TO LOWER 90S.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
ISSUED AT 202 PM CDT MON JUL 27 2026
TUESDAY NIGHT THROUGH THURSDAY WILL CONTINUE TO BE ON THE DRY SIDE,
THANKS TO AN AREA OF HIGH PRESSURE/SUBSIDENCE THAT'S PROGGED TO
DEVELOP OVER THE WESTERN GREAT LAKES, ALONG WITH AN UPPER-LEVEL
RIDGE OVER THE GREAT PLAINS REGION. TEMPERATURES WILL REMAIN
SEASONABLY WARM, WITH HIGH TEMPERATURES FORECAST FOR WEDNESDAY AND
THURSDAY IN THE MIDDLE TO UPPER 80S, AND NIGHTTIME LOWS IN THE
MIDDLE 60S.
AS WE GO THROUGH THE DAY THURSDAY, THE AFOREMENTIONED UPPER RIDGE
BEGINS TO BREAK DOWN, WITH A MID-LEVEL SHORTWAVE TROUGH EMBEDDED IN
THE ZONAL FLOW. A QUASI VERTICALLY-STACKED UPPER LOW WILL ACCOMPANY
THE TROUGH, WHICH WILL HELP FURTHER SUPPORT LARGE-SCALE FORCING OVER
OUR REGION. LIKELY CHANCES OF SHOWERS AND THUNDERSTORMS (50-70%)
LOOK TO INCREASE LATE THURSDAY NIGHT INTO FRIDAY. AT THIS TIME,
STRONG TO SEVERE STORM POTENTIAL FOR THIS PERIOD APPEARS TO BE
PRETTY LOW, GIVEN MEAGER INSTABILITY AND DEEP-LAYER SHEAR MAGNITUDES
(20-30 KNOTS). THE LATEST MACHINE-LEARNING SEVERE PROBS FROM NSSL,
NCAR, AND CSU ALL SHOW VERY SMALL VALUES, IF ANYTHING. MORE LIKELY,
THIS BOUT OF PRECIPITATION APPEARS TO BRING BENEFICIAL RAINFALL TO
THE AREA, WITH THE LATEST NBM EXCEEDANCE PROBABILITIES OF A HALF
INCH OF TOTAL RAINFALL THROUGH 12Z/7 AM SATURDAY AROUND 40 TO 60%
ACROSS THE AREA. WITH THE PRECIPITATION AND COOLER AIR MASS BUILDING
IN, TEMPERATURES LOOK TO BE COOL EVEN FURTHER FOR THE END OF THE
WEEK, WITH HIGHS WARMING TO AROUND 80 DEGREES FOR FRIDAY AND
SATURDAY - A WELCOMED SIGN FOR THOSE LOOKING FOR RELIEF FROM THE
HEAT.
SATURDAY AND SUNDAY: THERE COULD BE SOME LINGERING CHANCES OF
SHOWERS/STORMS SATURDAY MORNING BEFORE THE AFOREMENTIONED STACKED
UPPER LOW MOVES OUT AND ANOTHER HIGH PRESSURE SYSTEM BUILDS IN,
BRINGING DRIER CONDITIONS TO THE AREA.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1217 AM CDT TUE JUL 28 2026
VFR CONDITIONS ARE EXPECTED FOR THE DURATION OF THE TAF PERIOD.
METAR OBSERVATIONS SHOW THAT THE COLD FRONT HAS PASSED THROUGH ALL
TERMINALS, TURNING WINDS NORTHWESTERLY TO NORTHERLY. WITH
INCOMING MID AND HIGH CLOUDS, RADIATIONAL COOLING SHOULD SLOW
ENOUGH TO LIMIT ANY PATCHY AREAS OF FOG THROUGH THIS MORNING.
WHILE THERE WILL BE HIGH CONCENTRATIONS OF SMOKE ALOFT, IT IS
UNLIKELY THAT THIS SMOKE WILL MIX DOWN TO THE SURFACE AND LIMIT
VISIBILITY.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...08
LONG TERM...SCHULTZ
AVIATION...ELLINGWORTH
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