716
FXUS63 KDVN 311924
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
224 PM CDT SAT MAY 31 2025
KEY MESSAGES
- SMOKE ALOFT FROM CANADIAN WILDFIRES WILL CONTINUE TO STREAM SOUTHWARD
THROUGH THE WEEKEND. SOME OF THE SMOKE COULD MIX DOWN TO THE
SURFACE AND LEAD TO REDUCED AIR QUALITY AT TIMES.
- ACTIVE PATTERN RETURNS TUESDAY THROUGH THURSDAY NEXT WEEK, BRINGING
HIGHER CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS. SOME
STORMS COULD BECOME STRONG TO SEVERE ON TUESDAY.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 217 PM CDT SAT MAY 31 2025
THE MAIN STORY FOR THE WEEKEND CONTINUES TO BE THE LINGERING SMOKE
ALOFT FROM CANADIAN WILDFIRES. THIS IS BEING SENT SOUTHWARD ON
NORTHERLY FLOW ALOFT AS WE REMAIN ON THE WESTERN SIDE OF A DEEP
LONGWAVE TROUGH THAT WILL LOITER OVER THE NORTHEASTERN CONUS THROUGH
SUNDAY NIGHT. THE HRRR'S VERTICALLY-INTEGRATED SMOKE OUTPUT
DEPICTS THE SMOKE JUST CONTINUING TO STREAM SOUTHWARD TODAY AND
SUNDAY, SO EXPECT TO SEE HAZY SKIES ACROSS THE AREA. VERTICAL
CROSS SECTIONS FROM THE HRRR NEAR OUR AREA CONTINUE TO SHOW THE
SMOKE AROUND THE 850-700 MB LAYER, SO IF THE BOUNDARY LAYER CAN
MIX THAT DEEPLY, WHICH IT MIGHT BE ABLE TO DO TODAY AND SUNDAY,
THEN SOME OF THE SMOKE COULD MIX DOWN TO THE SURFACE. THERE
CONTINUES TO BE SOME DIFFERENCES AMONG THE HRRR AND RAP SMOKE
MODELS ON THE EXACT CONCENTRATION OF SURFACE SMOKE, WITH THE
HRRR MORE AGGRESSIVE THAN THE RAP, BUT BOTH INDICATE AT LEAST A
SMALL DEGREE OF SMOKE ABLE TO REACH THE SURFACE, WHICH COULD
LEAD TO REDUCED AIR QUALITY.
MEANWHILE, A BACKDOOR COLD FRONT HAS MADE ITS WAY INTO THE REGION
THIS AFTERNOON FROM THE NORTHEAST, WHICH IS EVIDENT BY A WIND-SHIFT
LINE, WITH FLOW FROM THE NORTHEAST OVER OUR NORTHEASTERN CWA. SO
FAR, NO SHOWERS HAVE DEVELOPED ALONG THE BOUNDARY, BUT SBCAPE OF 500-
1000 J/KG PER THE 31.12Z HREF ENSEMBLE SUGGESTS AT LEAST MODEST
INSTABILITY TO GENERATE SOME SHOWERS. HOWEVER, CAMS ARE STILL
IN DISAGREEMENT ON IF ANYTHING WILL DEVELOP THIS AFTERNOON AND
EVENING, SO WE HAVE MAINTAINED VERY LOW POPS (<20%) FOR THIS
TIME FRAME.
CONDITIONS WILL REMAIN DRY ON SUNDAY AS AN AREA OF HIGH PRESSURE
DOMINATES THE REGION, WITH TEMPERATURES CONTINUING TO INCREASE, WITH
HIGHS IN THE LOWER TO MIDDLE 80S (WARMEST TO THE WEST).
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED AT 217 PM CDT SAT MAY 31 2025
THE LONG-TERM FORECAST PERIOD STARTS OFF ON A DRY AND QUIET
NOTE MONDAY, THANKS TO AN UPPER-LEVEL RIDGE OVER THE PLAINS
REGION SUSTAINING A DRY AIR MASS IN PLACE. NORTHERLY FLOW ALOFT
DOES APPEAR TO CONTINUE INTO MONDAY, SO WE MIGHT STILL BE SEEING
SOME HAZY SKIES FROM THE WILDFIRE SMOKE. OTHERWISE, THE MAIN
STORY FOR MONDAY WILL BE EVEN HOTTER TEMPERATURES AS 850 MB
TEMPERATURES PER THE LATEST EC AND GEFS ENSEMBLES INCREASE TO
BETWEEN 15-18 DEGREES C, WHICH IS AROUND THE 90TH PERCENTILE PER
THE SPC SOUNDING CLIMATOLOGY. THE LATEST ECMWF EFI FOR HIGH
TEMPERATURES ON MONDAY IS ACTUALLY SHOWING A LARGER FOOTPRINT
FOR VALUES BETWEEN 0.7 TO 0.9 THAN PREVIOUS RUNS, EVEN WITH A
FEW ISOLATED SPOTS EXCEEDING 0.9. THIS SUGGESTS A PRETTY STRONG
SIGNAL FOR VERY WARM CONDITIONS MONDAY, WITH THE LATEST NBM
HIGH TEMPERATURES FOR MONDAY WARMING TO THE UPPER 80S TO LOWER
90S ACROSS THE AREA.
FOR TUESDAY THROUGH THURSDAY, A MORE ACTIVE PATTERN IS EXPECTED AS
AN UPPER-LEVEL TROUGH AND ATTENDANT COLD FRONT APPROACHES THE
REGION. ABUNDANT MOISTURE FROM THE GULF SHOULD ADVECT HIGHER PWAT
VALUES AROUND 1.7 TO 2.0 INCHES PER THE GEFS ENSEMBLE PLUMES BY
TUESDAY AFTERNOON. THIS FIRST TROUGH SHOULD PHASE IN WITH A SOUTHERN
STREAM TROUGH COMING FROM THE SOUTHWESTERN CONUS, ARRIVING ON
THURSDAY. COMBINED, THESE TWO WAVES WILL RESULT IN A PROLONGED
PERIOD OF RAINFALL CHANCES TUESDAY THROUGH THURSDAY (THOUGH NOT A
COMPLETE WASHOUT), WITH A SOAKING RAINFALL EXPECTED ACROSS THE
AREA. LOOKING AT A 72-HR PERIOD FROM TUESDAY THROUGH THURSDAY,
NBM EXCEEDANCE PROBABILITIES OF ONE INCH OR MORE OF TOTAL
RAINFALL IS BETWEEN 50 TO 80 PERCENT AND BETWEEN 20 TO 40
PERCENT FOR TWO INCHES OR MORE. IT'S STILL A LITTLE EARLY TO
ASSESS SPECIFIC DETAILS FOR THE SEVERE WEATHER POTENTIAL, WHICH
WILL DEPEND ON THE TIMING OF THE COLD FRONT TUESDAY. WITH THAT
SAID, MACHINE LEARNING GUIDANCE CONTINUES TO HIGHLIGHT THE AREA
WITH LOWER-END SEVERE WEATHER PROBABILITIES (~15%) ON TUESDAY
AND SPC HAS MAINTAINED A DAY 4 SLIGHT RISK (LEVEL 2 OF 5) OVER
NEARLY THE ENTIRE FORECAST AREA. EXPECT SOME ADJUSTMENTS TO
THESE COVERAGE DETAILS AS WE GET CLOSER TO THE EVENT AS NEW
MODELS BECOME AVAILABLE.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1230 AM CDT SAT MAY 31 2025
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD. A WEAK
COLD FRONT CONTINUES TO SWEEP INTO THE AREA FROM THE NORTHEAST,
LEADING TO A NORTHEASTERLY WIND SHIFT FOR DBQ AND LIKELY FOR
MLI LATER ON BEFORE ALL WINDS GO LIGHT AND VARIABLE TONIGHT.
CONFIDENCE IN DRY CONDITIONS ALONG THE FRONT HAS ACTUALLY
INCREASED THIS MORNING, GIVEN MORE MODELS NOW KEEPING OUR AREA
DRY, SO MAINTAINED A DRY FORECAST. WILDFIRE SMOKE ALOFT WILL
REMAIN OVER THE AREA THROUGH THE PERIOD AND COULD POTENTIALLY
MIX DOWN TO THE SURFACE AT TIMES IN LOW CONCENTRATIONS.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...SCHULTZ
LONG TERM...SCHULTZ/UTTECH
AVIATION...SCHULTZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page