553
FXUS63 KDVN 180544
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1244 AM CDT SAT APR 18 2026
KEY MESSAGES
- MUCH COOLER CONDITIONS ARE EXPECTED THIS WEEKEND. UNSEASONABLY COOL
TEMPERATURES IN THE 30S SATURDAY NIGHT AND SUNDAY NIGHT WILL
BRING THE POTENTIAL FOR FROST/FREEZE, ESPECIALLY IN OUR NORTH.
- AREA RIVERS ARE ON THE RISE FROM THE RECENT ROUNDS OF HEAVY
RAIN, AND HEAVY RAINFALL LATER TODAY MAY PUSH THEM EVEN
HIGHER. REFER TO THE HYDRO SECTION BELOW FOR MORE DETAILS.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 1252 PM CDT FRI APR 17 2026
CONVECTIVE INITIATION HAS OCCURRED ACROSS EASTERN IOWA. THE
INDIVIDUAL DISCRETE CELLS WILL RAPIDLY GROW UPSCALE INTO ONE OR
MORE BROKEN LINES AHEAD OF THE COLD FRONT.
THE ATMOSPHERE IS BECOMING INCREASINGLY MOIST SO THE STORMS WILL
HAVE PLENTY OF FUEL TO PRODUCE HEAVY RAINFALL. THE AXIS FOR THE
HEAVIER RAIN IS SOMEWHAT NARROW BUT RAINFALL AMOUNTS OF AN INCH
IN AN HOUR WILL BE POSSIBLE WITH THE STRONGER STORMS. WHERE
STORMS LINGER OR REPEAT OVER THE SAME AREAS, RAINFALL AMOUNTS
OF 2 TO 3 INCHES IN A SHORT TIME WILL BE POSSIBLE.
THE PRE-FRONTAL LINE(S) OF STORMS LOOK TO PUSH EAST OF THE
MISSISSIPPI IN THE 6-8 PM TIME FRAME WITH THE COLD FRONT
ARRIVING DURING THE MID TO LATE EVENING HOURS. VERY SHORT RANGE
MODELS WHICH HAD BEEN POINTING TO A SOLID LINE OF STORMS WITH
THE FRONT ARE NOW TRENDING TOWARD A SCATTERED TO BROKEN LINE
WITH NOT MUCH THUNDER ASSOCIATED WITH IT. THIS 'MAY' BE AN
INDICATION THE CONVECTIVE ALLOWING MODELS ARE STRUGGLING WITH
THE OVERALL FORCING FROM THE UPPER LEVEL SYSTEM.
THE BULK OF THE RAIN LOOKS TO END ACROSS THE AREA BY MIDNIGHT
BUT SCATTERED RAIN SHOWERS ALONG AND IMMEDIATELY BEHIND THE
FRONT WILL LINGER PAST MIDNIGHT. HOWEVER, THE OVERALL TREND WILL
BE DECREASING AREAL COVERAGE FROM WEST TO EAST AFTER MIDNIGHT.
LONG TERM /SUNDAY THROUGH FRIDAY/
ISSUED AT 306 AM CDT FRI APR 17 2026
MUCH COLDER AIR WILL CONTINUE TO MOVE INTO THE AREA FOR THE WEEKEND
AS A NORTHWEST FLOW PATTERN DEVELOPS ALOFT. AN AREA OF HIGH PRESSURE
WILL BUILD INTO THE AREA SATURDAY NIGHT, WHICH COULD SET UP OUR
FIRST BOUT OF FROST/FREEZE CONDITIONS DURING THE GROWING SEASON.
THERE DOES APPEAR TO BE A MID-LEVEL TROUGH SWEEPING THROUGH THE AREA
SATURDAY NIGHT, WHICH COULD RESULT IN SOME CLOUD COVER THAT COULD
KEEP OUR TEMPERATURES FROM FALLING TOO MUCH, LIMITING OUR
FROST/FREEZE POTENTIAL. DESPITE THIS, THE NBM PROBABILITIES OF
FREEZING TEMPERATURES SATURDAY NIGHT ARE STILL AROUND 50-80% ALONG
AND NORTH OF INTERSTATE 80. ANOTHER NIGHT OF FROST/FREEZE CONDITIONS
ARE POSSIBLE SUNDAY NIGHT AS WELL, WITH SIMILAR EXCEEDANCE
PROBABILITIES FOR FREEZING TEMPERATURES.
A QUIETER WEATHER PATTERN WILL PERSIST INTO EARLY NEXT WEEK AS A
BROAD UPPER RIDGE REMAINS IN PLACE THROUGH THE CENTRAL US. A LARGER
TROUGH BEGINS TO TAKE SHAPE ACROSS THE WESTERN US INTO THE LATTER
PORTION OF THE WEEK. THEREFORE, SOME WARMING AND A MOVE TOWARD SOME
SMALLER PRECIPITATION CHANCES (20-40%) START TO RETURN TO THE AREA
BY THURSDAY WITH A LARGER STORM SYSTEM POTENTIALLY NEARING THE
REGION FOR FRIDAY.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1244 AM CDT SAT APR 18 2026
A COLD FRONT HAS SWEPT THROUGH THE AREA EARLIER THIS EVENING,
HELPING TO SCOUR OUT SHOWERS AND STORMS TO THE EAST, AND
TURNING OUR WINDS OUT OF THE NORTHWEST. VFR CONDITIONS WILL
CONTINUE THROUGHOUT THE TAF PERIOD, WITH GUSTY NORTHWEST WINDS
TO AROUND 20 TO 25 KNOTS THROUGH SATURDAY EVENING BEFORE
WEAKENING SATURDAY EVENING.
HYDROLOGY
ISSUED AT 1136 AM CDT THU APR 16 2026
DISCUSSION...
OVER THE PAST FIVE DAYS, MULTIPLE ROUNDS OF HEAVY RAIN HAVE
IMPACTED EASTERN IOWA, NORTHERN ILLINOIS AND SOUTHERN WISCONSIN.
RAINFALL AMOUNTS HAVE RUN FROM 2 TO 5 INCHES OF RAIN; MUCH OF
THIS RAIN HAS BEEN NORTH OF HIGHWAY 30.
ANOTHER ROUND OF HEAVY RAIN IS FORECAST THIS AFTERNOON AND
EVENING WITH AMOUNTS RUNNING FROM A HALF INCH TO AROUND 1.5
INCHES. WITH AREA SOILS RUNNING FROM MOIST TO NEAR SATURATION,
THIS ADDITIONAL RAINFALL WILL QUICKLY RUN OFF INTO AREA
WATERWAYS RESULTING IN NEW OR INCREASED RIVER FLOODING ALONG
WITH THE POTENTIAL FOR FLASH FLOODING.
MUCH OF THIS RAIN IS FORECAST TO FALL ACROSS SOUTHEAST IOWA,
WEST CENTRAL ILLINOIS AND INTO NORTHERN ILLINOIS. RIVER BASINS
IMPACTED WOULD BE THE ROCK, LOWER IOWA, SKUNK, DES MOINES AND LA
MOINE.
ROCK RIVER...
BASED ON OVERALL RIVER FORECASTS AND ANOTHER ROUND OF HEAVY RAIN
EXPECTED TODAY, CONFIDENCE IS HIGH (>80%) THAT THE ENTIRE
LENGTH OF THE ROCK RIVER WILL REACH FLOOD STAGE BY THE WEEKEND
AND REMAIN ABOVE FLOOD STAGE INTO MUCH OF NEXT WEEK.
MISSISSIPPI RIVER...
ROUTED FLOW COMING DOWN FROM THE UPPER MISSISSIPPI, WISCONSIN,
ROCK, IOWA AND OTHER TRIBUTARY RIVERS WILL CAUSE GENERAL RISES
ALONG THE LENGTH OF THE MISSISSIPPI. BASED ON THE CURRENT ROUTED
FLOW AND ANOTHER ROUND OF HEAVY RAIN, CONFIDENCE IS HIGH (>80%)
THAT THE MISSISSIPPI WILL REACH FLOOD STAGE FROM MUSCATINE DOWN
THROUGH KEITHSBURG AND AT GREGORY LANDING. GLADSTONE AND
BURLINGTON ARE ALREADY ABOVE FLOOD STAGE AND WILL SEE ADDITIONAL
RISES AS THE ADDITIONAL ROUTED FLOW ARRIVES OVER THE WEEKEND
AND INTO NEXT WEEK.
IOWA TRIBUTARY RIVERS...
RIVERS IN EASTERN IOWA ARE RUNNING HIGH FROM THE ROUNDS OF HEAVY
RAIN. FLOOD WARNINGS CONTINUE FOR THE LOWER WAPSIPINICON RIVER
NEAR DEWITT AND THE IOWA RIVER ABOVE CORALVILLE NEAR MARENGO.
BASED ON ROUTED FLOW, THE LOWER CEDAR RIVER NEAR CONESVILLE WILL
GO ABOVE FLOOD STAGE OVER THE WEEKEND.
THE NORTH SKUNK RIVER NEAR SIGOURNEY IS FORECAST TO GO ABOVE
FLOOD STAGE TONIGHT WITH GENERAL RISES EXPECTED FARTHER
DOWNSTREAM AND ON THE SKUNK RIVER.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...08
LONG TERM...SCHULTZ
AVIATION...SCHULTZ
HYDROLOGY...08
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