486
FXUS63 KDVN 202322
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
622 PM CDT MON APR 20 2026
KEY MESSAGES
- TEMPERATURES WILL BE NOTICEABLY WARMER TONIGHT THROUGH
THURSDAY WITH HIGH TEMPERATURES EACH DAY IN THE MID TO UPPER
70S.
- A WEAK STORM SYSTEM WILL BRING LOW CHANCES (10 TO 40%) FOR
SHOWERS AND STORMS LATE TUESDAY AFTERNOON AND EVENING SOUTH
OF INTERSTATE 80.
- WIDESPREAD SHOWERS AND STORMS RETURN THURSDAY INTO FRIDAY
MORNING. THERE IS THE POTENTIAL FOR STRONG STORMS.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED AT 226 PM CDT MON APR 20 2026
IT WILL BE TURNING WARMER DURING THE SHORT TERM AS HIGH PRESSURE
SHIFTS TO THE EAST AND WARM SOUTHERLY FLOW TAKES OVER. WINDS ARE
FORECAST TO REMAIN GUSTY THIS EVENING WITH GUSTS UP TO 25 MPH
ARE POSSIBLE. IT WILL BE NOTICEABLY WARMER ON TUESDAY WITH LOW
TEMPERATURES RANGING FROM THE UPPER 40S NORTH OF INTERSTATE 80
TO THE LOWER 50S SOUTH.
A WEAK SHORTWAVE IS FORECAST TO MOVE THROUGH THE NORTHWESTERLY FLOW
ALOFT TUESDAY INTO TUESDAY NIGHT. THIS WILL DRIVE A COOL FRONT
ACROSS THE REGION DURING THE AFTERNOON. THIS FRONT IS FORECAST
TO STALL NEAR THE HIGHWAY 34 CORRIDOR ON TUESDAY. HIGH
TEMPERATURES ON TUESDAY ARE FORECAST TO BE IN THE MID TO UPPER
70S ACROSS THE AREA. MOISTURE IS SHOWN POOLING ALONG THE FRONT
WITH FORECAST CAPE VALUES OF 500 TO 1500 WITH 0 TO 6 KM SHEAR
AROUND 30 KNOTS BUT THE ATMOSPHERE IS CAPPED IN THE LOWER LEVELS
AND WE ARE NOT OUTLOOKED FOR SEVERE STORMS DUE TO LOWER
MOISTURE AND THE CAPPING INVERSION. CHANCE OF PRECIPITATION ARE
10 TO 40 % MAINLY ALONG AND SOUTH OF HIGHWAY 30 LATE AFTERNOON
INTO THE EVENING. IF STORMS DO DEVELOP IN THIS ENVIRONMENT,
GUSTY THUNDERSTORM WINDS AND SMALL HAIL WILL BE THE MAIN
THREATS. LOW TEMPERATURES ON WEDNESDAY MORNING ARE FORECAST TO
RANGE FROM THE UPPER 40S NORTH OF HIGHWAY 30 TO THE UPPER 50S
SOUTH OF INTERSTATE 80.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 226 PM CDT MON APR 20 2026
RIDGING WILL BE IN PLACE AT THE SURFACE AND ALOFT WEDNESDAY WITH
WARM WEATHER CONTINUING ACROSS THE REGION AND DRY CONDITIONS.
HIGH TEMPERATURES ON WEDNESDAY WILL BE IN THE MID TO UPPER 70S.
THERE WILL BE GUSTY SOUTH WINDS ACROSS THE REGION WITH GUSTS UP
TO 20 MPH.
ATTENTION THEN TURNS TO THURSDAY INTO FRIDAY, AS A BROAD, UPPER-
LEVEL TROUGH DEVELOPS OVER THE WESTERN CONUS ON TUESDAY AND SLOWLY
MAKES ITS WAY EASTWARD, BECOMING MORE NEGATIVELY TILTED WITH TIME.
LIKELY CHANCES (70-90%) OF SHOWERS AND STORMS WILL INCREASE THURSDAY
AFTERNOON AND EVENING, AND CONTINUE INTO FRIDAY MORNING. THIS
SCENARIO HAS BEEN CONSISTENT WITH BRINGING A SURFACE COLD FRONT
ATTENDANT TO THE TROUGH, WITH A PRE-FRONTAL SHORTWAVE IMPULSE AHEAD
OF THE BOUNDARY. THE CONVECTIVE PARAMETER SPACE STILL SHOWS MORE
MODEST INSTABILITY AND SHEAR, WITH MLCAPE VALUES AROUND 500 TO 1000
J/KG AND DEEP-LAYER SHEAR AROUND 20 TO 30 KNOTS. THE VARIOUS MACHINE
LEARNING SEVERE WEATHER PROBABILITIES STILL SHOW NOTABLE VALUES FOR
OUR REGION (EQUIVALENT TO A SLIGHT RISK), LIKELY OWING TO THE
STRONGER LARGE-SCALE FORCING.
AS WE GO INTO NEXT WEEKEND, THE UPPER-LEVEL TROUGH DOES PASS THROUGH
THE AREA, BUT A LARGE UPPER-LEVEL LOW APPEARS TO TAKE SHAPE OVER
SOUTH-CENTRAL CANADA, PLACING OUR REGION UNDER BROAD CYCLONIC FLOW.
THIS WILL BRING GENERALLY COOLER CONDITIONS, WITH PERIODIC CHANCES
OF SHOWERS AND PERHAPS A FEW STORMS AS A COUPLE OF MID-LEVEL
SHORTWAVES REVOLVE AROUND THE UPPER LOW.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 619 PM CDT MON APR 20 2026
A PARTIAL DECOUPLING OF THE LOWER ATMOSPHERE WILL OCCUR WITH
SUNSET BUT SPORADIC GUSTS UP TO 18 KNOTS ARE POSSIBLE. AFTER
04Z/21 LLWS WILL DEVELOP AROUND 1.5 KFT AGL PLUS/MINUS 200 FEET WITH
WINDS UP TO 45 KNOTS. AFTER 14Z/21 THE NOCTURNAL INVERSION WILL
BREAK ALLOWING GUSTS UP TO 25 KNOTS IN LOW LEVEL MECHANICAL
TURBULENCE.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...COUSINS
LONG TERM...SCHULTZ
AVIATION...08
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page