660
FXUS63 KDVN 190558
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1258 AM CDT TUE MAY 19 2026
..06Z AVIATION UPDATE
KEY MESSAGES
- THUNDERSTORMS ARE EXPECTED TO HOLD OFF UNTIL MID TO LATE
EVENING TONIGHT AS THE MAIN SEVERE WEATHER THREAT REMAINS
TIED TO THE COLD FRONT POSITION WELL TO OUR WEST THIS
AFTERNOON.
- A MATURE TO DISSIPATING SQUALL LINE OF STORMS IS EXPECTED TO
MOVE TOWARDS OUR WESTERN COUNTIES LATER THIS EVENING, AND
BEGIN TO DISSIPATE/BREAK UP AS IT MOVES EASTWARD.
- COOLER WEATHER IS EXPECTED FOR THE MID TO LATE WEEK, WITH
INCREASING RAIN CHANCES THURSDAY NIGHT THROUGH FRIDAY.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 200 PM CDT MON MAY 18 2026
TWO AREAS OF SCATTERED STORMS AND RAIN MOVED THROUGH THE AREA EARLY
THIS MORNING, RESULTING IN SOME BENEFICIAL RAINFALL, AND EXTENSIVE
CLOUD COVER OVER THE AREA THROUGH THIS MORNING. THE CLOUD COVER HAS
RESULTED IN FAR LESS INSTABILITY AVAILABLE FOR ANY STORMS OVER
EASTERN IOWA THIS AFTERNOON, WHILE ILLINOIS AND MISSOURI CONTINUES
TO SEE OVER-RUNNING RAINS JUST SOUTH OF OUR COUNTIES FROM THE
EXPANSION OF THE EARLY MORNING STORM CLUSTER THAT IMPACTED OUR CWA
TODAY. THIS VAST AREA OF STABLE AIR SHOULD KEEP ANY PREFRONTAL
STORMS FROM FORMING IN OUR CWA THIS AFTERNOON AND EARLY EVENING.
FARTHER WEST, A DIFFERENT STORY EXISTS. STRONG HEAT AND CONVERGENCE
IS OVER EASTERN KS, FEEDING INTO A TRIPLE POINT JUST NORTH OF SALINA
KS. THIS RATHER OBVIOUS SPOT WITH STRONGLY BACKED WINDS, AMPLE CAPE,
AND FOCUSING MECHANISM SUPPORTS SUPERCELL GROWTH IN EASTERN KS,
SOUTHEAST NE, NORTHWEST MO, AND FAR SOUTHWEST IOWA THIS
AFTERNOON THROUGH MID EVENING, AS IS OUTLINED BY SPC FOR A
MODERATE AND ENHANCED RISK. THAT ENH RISK PREVIOUSLY INCLUDED
EASTERN IOWA, BUT HAS BEEN SHIFTED WEST DUE TO THE LATE ARRIVAL
TIME, AND EXPECTATION OF INSTABILITY WANING OVERNIGHT.
VARIOUS CAMS AGREE NEARLY ALL AGREE ON SUPERCELLS SPREADING EAST AND
NORTHEAST INTO SOUTHWEST IOWA THIS EVENING, MERGING INTO A LINE,
WITH BOWING SEGMENTS AND DAMAGING WINDS AS IS MOVES TOWARDS SOUTH
SOUTHWEST IOWA AND MO. FROM THIS POINT GOING FORWARD,
CONVECTION APPEARS TO SHOW THE HIGHEST POTENTIAL TO SPLIT NORTH
AND SOUTH, WITH THE NORTHERN SIDE MOVING TOWARDS WISCONSIN AND
MN FOLLOWING THE BEST SHEAR AND FORCING, WHILE THE MOST
SIGNIFICANT SEVERE WEATHER WILL DROP SOUTHEAST FROM ITS
INITIATION POINT IN EASTERN KS TO CENTRAL AND POSSIBLY NORTHERN
MO WITH A SIGNIFICANT WIND THREAT, AS WELL AS HEAVY RAIN IN MO.
FOR OUR CWA, THAT COULD LEAVE US OUT OF THE THREAT FOR SEVERE
WEATHER, HOWEVER GIVEN SOME THREAT FOR AN ORGANIZED LINE OF
STORMS ON THE NORTHERN FLANK OF THE MISSOURI ACTIVITY, WE COULD
SEE A GUSTY SQUALL LINE MOVE FROM WEST TO EAST OVER THE AREA, AS
SHEAR VALUES WILL BE SUFFICIENT FOR THIS TO HAPPEN. IN FACT, IF
IT DOES HAPPEN, 0-1KM SHEAR VECTORS COULD ALLOW FOR SOME QLCS
TORNADO POTENTIAL AS DAMAGING MESO VORTS ALONG THE LINE. (IF WE
GET A COHERENT LINE OVERNIGHT).
ACTIVITY WILL BE DECAYING REGARDING QPF OVERNIGHT, WITH MOST
RAINFALL EXPECTED IN OUR SOUTHERN COUNTIES ONCE AGAIN. BY EARLY
TUESDAY MORNING, ANY RAIN WILL BE QUICKLY EXITING OUR SOUTHEAST CWA
WITH A CLOUDY COOL MORNING IN PLACE. NORTHWEST WINDS WILL BRING IN
PLENTY CAA TUESDAY AND TUESDAY EVENING, AS TEMPERATURES FALL FROM
HIGHS IN THE LOW 60S WEST TO MID 70S EAST TO THE 40S BY MID EVENING
TUESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
ISSUED AT 200 PM CDT MON MAY 18 2026
COOL HIGH PRESSURE LOOKS TO MOVE IN FOR TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT, RESULTING IN LOWS IN THE 40S, BUT HIGHS IN THE MID
TO UPPER 60S. THIS RATHER NICE WEATHER WILL GIVE WAY TO POTENTIAL
RAIN AND CLOUDS FOR THURSDAY AFTERNOON THROUGH FRIDAY AS THERE IS A
GROWING SIGNAL FOR AN UPPER LOW/DEEP TROF PASSING THROUGH THE
MIDWEST IN THAT TIME FRAME. POPS ARE NOW INCREASED TO LIKELY (55-
70%) FOR THURSDAY NIGHT AND FRIDAY, WITH SOME THUNDER POSSIBLE. THE
CLOUDS AND SHOWERS WILL HOLD TEMPERATURES DOWN INTO THE 60S BOTH
DAYS, BEFORE A WARM UP INTO THE 70S AND 80S SPREADS IN FOR THE
WEEKEND.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1250 AM CDT TUE MAY 19 2026
ANOTHER NIGHT OF STRONG LLVL WINDS AND A LINEAR MCS MOVING
THROUGH THE TAF SITES. AFTER THE MAIN LINE PUSHES THROUGH,
BEHIND IT MORE STRATIFORM RAIN WITH SOME EMBEDDED THUNDER AND
PATCHES OF WAKE LOW WIND FIELDS GUSTING UP TO 40-50 KTS OUT OF
THE BACKSIDE OF THE DEPARTING PRECIP SHIELD. THE MAIN UPSTREAM
COLD FRONT WILL SLIP THROUGH TUESDAY MORNING FROM WEST-TO-EAST
WITH A SFC WIND VEER TO THE WEST AND EVENTUALLY NORTHWEST AS
TUESDAY MORNING PROGRESSES. THE NORTHWEST WINDS MAY GUST 25-30
KTS. ALONG AND POST-FRONTAL THERE IS A SUBSTANTIAL FIELD OF MVFR
STRATOCU THAT WILL MOVE ACRS MOST OF THE AREA THROUGH EVENING,
BEFORE SOME EROSION AND CLEARING OCCURS TUESDAY EVENING.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...ERVIN
LONG TERM...ERVIN
AVIATION...12
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