439
FXUS63 KDVN 170801
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
301 AM CDT SUN MAY 17 2026
KEY MESSAGES
- THE ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH MONDAY, WITH POTENTIAL
FOR STRONG TO SEVERE STORMS EACH CALENDAR DAY AND MAINLY AT
NIGHT. CONFIDENCE ON THE DAY BY DAY AREAL COVERAGE AND TIMING
REMAINS LOW.
- THE WARM AND MORE HUMID STRETCH WILL LAST THROUGH EARLY
TUESDAY, BEFORE A STRONG COLD FRONT SWEEPS THROUGH THE AREA
BRINGING COOLER CONDITIONS FOR THE MID-WEEK PERIOD.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 300 AM CDT SUN MAY 17 2026
REGIONAL RADAR LOOPS AND SATELLITE IMAGERY SUGGEST TWO "BOOKEND"
MCV'S ROLLING ACRS THE MIDWEST ATTM, ONE ACRS THE SOUTHWEST HALF OF
THE DVN CWA AND ANOTHER MORE UPSTREAM ACRS NE/KS/MO/IA QUAD STATE
REGION. NETWORK VWP'S SHOWING THESE WAVES BEING FED BY SOUTHWESTERLY
40-50+ KT LLJ FLOW IMPINGING ON THEIR SOUTHERN FLANKS. THE ONE
CLOSER TO HOME WILL CONTINUE TO MOVE NORTHEAST ACRS THE AREA THROUGH
6-7 AM WITH IT'S WEAKENING SHIELD OF RAIN WITH SOME EMBEDDED
THUNDER. THE OTHER ONE ACRS FAR NORTHWEST MO IS A LITTLE MORE
VIGOROUS AND MAY STILL HELP SOME STRONGER STORMS TO KEEP GOING WITH
IT'S SHEAR AS IT ROLLS ACRS THE NORTHWESTERN CWA THROUGH MID TO LATE
MORNING. SOME ADDITIONAL SWATHS OF HEAVY RAIN ALSO POSSIBLE THIS
MORNING WITH THESE TWO VORTEX'S.
THEN AS LONGER WAVE UPPER TROFFINESS ADJUSTS ACRS THE NORTHERN
ROCKIES, LEESIDE LLVL/SFC FRONTOGENESIS WILL LOOK TO ORGANIZE ACRS
THE CENTRAL PLAINS AND NORTHERN MO RVR VALLEY. AFTER THE MORNING TO
MIDDAY CONVECTIVE DEBRIS CLEARS, THE AREA TO BE ENGULFED IN THE WARM
BREEZY SECTOR TO THE LEE OF THE UPSTREAM FRONT. THIS SHOULD MAKE FOR
WIDESPREAD HIGHS IN THE LOW TO MID 80S TODAY AND SOME HUMIDITY WITH
SFC DPTS IN THE LOW TO MID 60S. TEMPORARY UPPER RIDGE BULGE IN
BETWEEN WAVES AND AN EML SHOULD MAKE FOR A DRY AFTERNOON AND
EVENING, AS MCS INITIATION TOOLS ALL SUGGEST THIS EVENING'S NEW
CONVECTION TO TAKE OFF ACRS THE MO RVR VALLEY AND MN. A ROBUST
SOUTHWESTERLY 50 KT H85 MB JET IS PROGGED TO MAINTAIN ACRS THE AREA,
AND THE UPSTREAM STORMS WILL LOOK TO PROPAGATE EAST-SOUTHEASTWRAD
INTO THE CWA NOT UNTIL WELL AFTER MIDNIGHT INTO EARLY MONDAY
MORNING. DEPENDING ON COLD POOL PROPAGATION MECHANICS AND OTHER
SUPPORT, THESE BANDED LINES OF STORMS WILL PROBABLY BE GENERALLY IN
A WEAKENING MODE AS THEY MAKE THEIR WAY ACRS THE AREA TOWARD SUNRISE
MONDAY, BUT STILL SOME THREAT FOR DAMAGING WINDS WITH SOME OF THE
LINES AS THEY ENTER THE WESTERN CWA. THEY PROBABLY WILL ALSO BE
DUMPING RAIN AT HIGH RAINFALL RATES, BUT A PROGRESSIVE NATURE TO THE
STORMS SHOULD LIMIT A FLASH FLOOD THREAT. LOW TEMPS IN THE MID TO
UPPER 60S.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 300 AM CDT SUN MAY 17 2026
MONDAY AND TUESDAY...A STRONGER COLD FRONT WILL LOOK TO ORGANIZE
UPSTREAM ACRS THE PLAINS AND UPPER MO RVR VALLEY ON MONDAY. IT WILL
BE ANOTHER DAY OF HAVING SOME CONVECTIVE DEBRIS AND OUTFLOW
BOUNDARIES TO WASH OUT AND RECOVER WITH SOUTHERLY FLOW AS THE DAY
PROGRESSES. HIGHS BACK IN THE 80S AND MID TO UPPER 60 DPTS WILL MAKE
FOR A NICE CAPE POOL LOCALLY WITH VALUES OVER 3000 J/KG POSSIBLE. A
STRONGER DIGGING UPPER TROF ON THE COLD FRONT OFF TO THE WEST WILL
LOOK TO LIGHT UP STRONG CONVECTION ACRS THE FAR EAST CENTRAL PLAINS
AND MID MO RVR VALLEY BY LATE MONDAY AFTERNOON. ANOTHER SCENARIO
WHERE THIS CONVECTION GROWS UPSCALE INTO A LINEAR MCS, AND MAY HAVE
BETTER SUPPORT TO MAINTAIN AS A SEVERE SQUALL LINE AS IT PROPAGATES
EASTWARD ACRS IA AND TOWARD THE LOCAL AREA LATER MONDAY NIGHT. A
SITUATION THAT WILL HAVE TO BE MONITORED OVER THE NEXT DAY AND A
HALF. ENSEMBLE TIMING HAS THE COLD FRONT SWEEPING THROUGH THE AREA
TUESDAY MORNING, TAKING THE CONVECTION WITH IT OFF TO THE EATS AND
SOUTHEAST OF THE AREA. A COOLER BLUSTERY POST FRONTAL DAY BY TUESDAY
AFTERNOON.
WEDNESDAY THROUGH SATURDAY...THE LATEST ENSEMBLES SUGGEST HIGH
PRESSURE REGIME TO SHUNT THE MAIN STORM TRACK TO THE SOUTH OF THE
REGION FOR MUSH OF THE MID TO LATE WEEK PERIOD. COOLER TEMPS IN THE
60S MODERATING BACK TO THE 70S BY FRIDAY. THE NEXT MAIN CHANCE FOR
PRECIP MAY NOT COME UNTIL FRIDAY IF THE LATEST WAVE HANDLING BY THE
ENSEMBLES IS CORRECT.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1255 AM CDT SUN MAY 17 2026
MCV AND IT'S ASSOCIATED SHIELD OF SHOWERS WITH EMBEDDED STORMS
WILL MOVE ACRS MOST OF THE TAF SITES THROUGH MID MORNING BEFORE
EXITING OFF TO THE NORTHEAST. THERE WILL BE BOUTS OF MVFR TO IFR
VSBYS AND CIGS THIS MORNING ALONG WITH VARIABLE SFC WINDS UNTIL
THIS FEATURE EXITS. THEN WITH A DEBRIS CLOUD CLEAR OFF,
SOUTHERLY WINDS WILL BECOME GUSTY UP TO 25-30 KTS BY AFTERNOON.
THE WINDS TO REMAIN BLUSTERY INTO THE EVENING, AND WITH SOME SFC
GUST DIMINISH THERE MAY BE A MARGINAL LLVL WIND SHEAR SCENARIO
SETTING UP FOR SUNDAY NIGHT AS A SOUTHWESTERLY LLJ REALLY CRANKS
UP TO AT LEAST 50 KTS. ANOTHER ROUND OF NOCTURNAL STORMS SHOULD
HOLD OFF AND NOT MOVE IN FROM THE WEST/NORTHWEST UNTIL AFTER
06Z MONDAY.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...12
LONG TERM...12
AVIATION...12
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