367
FXUS63 KDVN 022329
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
629 PM CDT SAT MAY 2 2026
..00Z AVIATION UPDATE
KEY MESSAGES
- A BLOCKED PATTERN WILL MAINTAIN A GENERAL NORTHWEST FLOW
ACROSS THE REGION FOR THE FIRST HALF OF THE PERIOD, WITH
EMBEDDED WAVES AND FRONTS COMBINING WITH DIURNAL
INSTABILITY/HEATING TO PRODUCE ALMOST DAILY CHANCES OF PRECIP
IN OR NEAR THE FORECAST AREA.
- THERE IS A MARGINAL (LEVEL 1 OUT OF 5) RISK FOR SEVERE
WEATHER MONDAY AFTERNOON FOR AREAS ALONG AND SOUTH OF HIGHWAY
34. PRIMARY THREATS ARE DAMAGING WINDS AND HAIL.
- WARM UP FOR SUNDAY INTO MONDAY, BEFORE COOLING BACK DOWN INTO
MID NEXT WEEK.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 154 PM CDT SAT MAY 2 2026
ENJOY A COOL AND DRY AFTERNOON BEFORE THE NEXT SHORTWAVE DIVES
INTO THE NORTHERN PLAINS TONIGHT. THIS TROUGH WILL PROMPT A
WEAK COLD FRONT TO MOVE IN EARLY SUNDAY MORNING FROM THE
NORTHWEST, ADVECTING SOME MID-LEVEL MOISTURE IN FROM THE
PACIFIC AND SHIFTING WINDS OUT OF THE SOUTH. A SHORT PERIOD OF
SCATTERED (30-40%) RAIN SHOWERS IS POSSIBLE FOR THE ENTIRE CWA
BETWEEN 3AM AND 10AM WITH THE FRONTAL PASSAGE, AND THE LACK OF
DAYTIME HEATING SHOULD LIMIT THE INSTABILITY AND THUNDER
POTENTIAL WITH THESE SHOWERS. CURRENT QPF FORECASTS HAVE A TRACE
TO A FEW HUNDREDTHS ACROSS THE AREA. WITH CLOUDS CLEARING AND
WINDS BECOMING WESTERLY BY SUNDAY AFTERNOON, HIGHS WILL CLIMB
INTO THE LOW-TO-MID 70S BEFORE PLUMMETING OVERNIGHT INTO THE
MID-40S WITH LIGHT AND VARIABLE WINDS.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 154 PM CDT SAT MAY 2 2026
MONDAY...LOOK FOR A RINSE AND REPEAT FROM SATURDAY NIGHT AS
ANOTHER SHORTWAVE RIDING OVER A RIDGE IN THE GULF OF ALASKA WILL
CAUSE THE LONGWAVE TROUGH OVER THE GREAT LAKES TO RETROGRADE
WESTWARD. A JET STREAK DIVING INTO MINNESOTA WILL SUPPORT
SURFACE CYCLOGENESIS ACROSS SOUTHWEST ONTARIO MONDAY MORNING
WHICH FORCES ANOTHER COLD FRONT SOUTHEASTWARD ACROSS THE
NORTHERN PLAINS MONDAY AFTERNOON. AGAIN, OUR MAIN MOISTURE
SOURCE WILL BE IN THE MID-LEVELS AS SOUTHERLY FLOW NEAR THE
SURFACE IS CURRENTLY FORECASTED TO LAST FOR ONLY 12-18 HOURS
PRIOR TO FRONTAL PASSAGE. HIGHS WILL BE ABLE TO CLIMB INTO UPPER
70S AND LOW 80S THOUGH. WITH A STRONGER TROUGH AND DAYTIME
HEATING, MUCAPE VALUES WILL BE AROUND 500 J/KG ACROSS THE CWA
AHEAD OF THE FRONT, POTENTIALLY ABOVE 1500 J/KG SOUTH OF THE
I-80 CORRIDOR. THIS IS WHY THE SPC CURRENTLY HAS A MARGINAL (1
OUT OF 5) RISK FOR SEVERE WEATHER ALONG AND SOUTH OF HIGHWAY 34
MONDAY AFTERNOON INTO THE EVENING WHERE THERE IS THE GREATEST
OVERLAP IN 0- 6 KM EFFECTIVE BULK SHEAR OF 40 KNOTS. PRIMARY
THREATS, CURRENTLY, ARE DAMAGING WINDS AND HAIL AS THE
UNIDIRECTIONAL SHEAR PROFILE DOES NOT FAVOR LOW-LEVEL HELICITY
NEEDED FOR TORNADOGENESIS. THE SEVERE THREAT IS FORECASTED TO
END OVERNIGHT MONDAY AS THE FRONT PASSES THROUGH, SHIFTING THE
WINDS BACK TO NORTHERLY.
TUESDAY... DESPITE THE COLD AIR ADVECTION IN THE LOW-LEVELS, A
FRONTOGENESIS BAND BETWEEN 700-500 MB WILL KEEP CLOUDS AROUND AND
THE POTENTIAL FOR A STRATIFORM RAIN SHIELD ALONG AND SOUTH OF I-80.
THERE IS MODEL UNCERTAINTY WITH THE NORTHERN EXTENT OF THIS RAIN
WITH THE 25TH PERCENTILE OF THE LREF HAVING NO QPF FOR THE ENTIRE
CWA WHILE THE 75TH PERCENTILE HAS 0.1-0.2 INCHES OF RAINFALL SOUTH
OF AND ALONG HIGHWAY 34. REGARDLESS THOUGH, THUNDER PROBABILITY
ON TUESDAY REMAINS LESS THAN 10%, AND HIGHS WILL BE COOL IN THE
MID-TO- UPPER 50S ACROSS MUCH OF THE AREA. THINGS WILL DRY OUT
TUESDAY NIGHT WITH PARTIAL CLEARING AND LOWS SLIGHTLY BELOW
AVERAGE IN THE LOW 40S.
WEDNESDAY-THURSDAY... THE LONGWAVE TROUGH OVER THE NORTHERN
PLAINS FINALLY EJECTS TO THE EAST WEDNESDAY INTO THURSDAY AS IT
PICKS UP A TROUGH IN THE SUBTROPICAL JET OVER THE DESERT
SOUTHWEST, SETTING UP A 110+ KNOT JET STREAK FROM NORTHERN
TEXAS UP TO MAINE. WHILE THIS JET STREAK WILL NOT BE PROVIDING
ANY DYNAMICAL SUPPORT ALOFT OVER IOWA, A VORTICITY MAXIMUM OVER
WISCONSIN AND SOME LINGERING MID-LEVEL MOISTURE WILL PROVIDE
THE CHANCE FOR SOME LIGHT SHOWERS THURSDAY AFTERNOON INTO THE
EVENING BEFORE DRY AIR IS FINALLY ADVECTED IN THURSDAY NIGHT.
FRIDAY-SATURDAY AFTERNOON... NORTHWEST FLOW ALOFT AND A HIGH
PRESSURE OVER THE GREAT LAKES IS EXPECTED TO BRING BACK THE SUNNY
SKIES AND HIGHS WILL REBOUND INTO THE UPPER 60S AND LOW 70S AND
LIGHT WINDS.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 625 PM CDT SAT MAY 2 2026
SFC WINDS WILL BACK MORE TO THE SOUTHWEST AND SOUTH TONIGHT AND
MAINTAIN 8-12 KTS AHEAD OF AN INCOMING FRONTAL SYSTEM THAT IS
CURRENTLY OFF TO THE NORTHWEST OF THE REGION. WITH THIS FRONT
THERE WILL BE AN INCREASE IN MID CLOUDS AND A CHANCE FOR SOME
SCTRD HIGH BASED SHOWERS TOWARD SUNDAY MORNING, BUT WITH THE DRY
LLVLS IT MAY BE HARD TO PRECIP-REDUCE VSBYS TO MVFR LEVELS. THE
PRE-FRONTAL SOUTH TO SOUTHWESTERLY SFC WINDS WILL BECOME GUSTY
UP OVER 20 KTS SUNDAY MORNING, THEN VEER TO THE WEST AS THE
AFTERNOON PROGRESSES AND THE FRONT SLIPS THROUGH THE AREA.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...DELAUNE
LONG TERM...DELAUNE
AVIATION...12
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