913
FXUS63 KDMX 091953
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
253 PM CDT THU APR 9 2026
KEY MESSAGES
- WIDESPREAD LIGHT TO MODERATE RAIN THIS EVENING WITH A FEW
SCATTERED STORMS POSSIBLE SOUTH. A FEW STORMS MAY HAVE SMALL
HAIL AND GUSTY WINDS. PROLONGED RAINFALL TONIGHT COULD LEAD TO
RISES ON SMALLER RIVERS AND BASINS.
- MORE SHOWER AND THUNDERSTORM CHANCES EXPECTED LATER SATURDAY
INTO SUNDAY. SEVERE WEATHER THREAT LOOKS LOW, BUT MORE
RAINFALL WILL CONTINUE TO ADD WATER TO RIVERS.
- ACTIVE WEATHER CONTINUES WITH SEVERAL ROUNDS OF RAIN AND
STORMS LATER SUNDAY INTO NEXT WEEK. SEVERE WEATHER AND HEAVY
RAINFALL WILL BE POSSIBLE AT TIMES WITH THESE STORMS.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 246 PM CDT THU APR 9 2026
RAIN AND SOME ISOLATED THUNDER HAS ALREADY STARTED TO IMPACT
PORTIONS OF SOUTH CENTRAL IOWA EARLY THIS AFTERNOON, AS WARM, MOIST
AIR OVERRUNS THE COOLER LOW LEVEL AIR MASS OVER IOWA. THE SURFACE
BOUNDARY IS CURRENTLY DRAPED OVER NORTHERN MISSOURI INTO CENTRAL
ILLINOIS, AND SHOULD GENERALLY REMAIN SOUTH OF THE STATE THROUGH THE
ENTIRETY OF THE AFTERNOON AND EVENING. THE 850 MB BOUNDARY, HOWEVER,
WILL INTRUDE FARTHER INTO THE STATE OVERNIGHT AHEAD OF A SHORTWAVE
PASSING TO OUR NORTH. THIS WILL ALLOW FOR A HEALTHY PUSH OF LOW- TO
MID-LEVEL THETA-E ADVECTION AND BROAD SCALE ASCENT OVER THE STALLED
SURFACE BOUNDARY TO OUR SOUTH. WIDESPREAD RAIN AND OCCASIONAL
THUNDERSTORMS WILL BE THE NET RESULT FROM THIS SETUP, IMPACTING MUCH
OF CENTRAL AND SOUTHERN IOWA THROUGH THE AFTERNOON AND INTO THE
EVENING HOURS. WEAK ELEVATED INSTABILITY WILL BE PRESENT WITH THIS
ACTIVITY, PRIMARILY OVER SOUTHERN IOWA AND SOUTHWESTERN IOWA WHERE
THUNDER WILL BE MORE LIKELY. BASED ON RECENT DATA, AGREE WITH THE
OVERNIGHT SHIFTS SYNOPSIS THAT THE SEVERE WEATHER THREAT LOOKS LOW,
BUT A STRONGER STORM CAN'T BE COMPLETELY RULED OUT. THE LIMITING
FACTOR TO STRONG STORMS THIS AFTERNOON AND EVENING WILL BE THE LACK
OF INSTABILITY. WITH THE SURFACE BOUNDARY GENERALLY REMAINING TO OUR
SOUTH, ANY STORMS WILL BE ELEVATED AND ONLY HAVE ACCESS TO
ROUGHLY 500 J/KG OF MOST UNSTABLE CAPE, WHICH WILL BE PRIMARILY
OVER SOUTHWEST AND SOUTHERN IOWA. WIND SHEAR WILL BE SUFFICIENT
FOR ORGANIZED CONVECTION, ASSUMING STRONGER UPDRAFTS CAN
DEVELOP. HOWEVER, WITH THE BROAD SYNOPTIC LIFT, WARM AIR
ADVECTION ALOFT AND A HEALTHY SURGE OF MOISTURE, SOUNDINGS SHOW
VERY SATURATED PROFILES WITH POOR MID-LEVEL LAPSE RATES,
IMPLYING THAT UPDRAFTS WOULD LIKELY BE WEAK AND SHORT-LIVED AS
THEY STRUGGLE TO FIND A SOURCE OF INFLOW. IF ANY STRONGER STORMS
DO DEVELOP, LIKELY IN SOUTHERN IOWA, GUSTY WINDS AND HAIL WOULD
BE THE PRIMARY CONCERNS. EVEN THEN, WITH SUCH WEAK CAPE, AND
WARM, SATURATED PROFILES, LARGE HAIL WILL BE DIFFICULT TO COME
BY.
WHILE THIS ENVIRONMENTAL SETUP DOESN'T NECESSARILY FAVOR SEVERE
WEATHER FOR OUR AREA, THE STOUT LOW LEVEL JET AND MOISTURE TRANSPORT
INTO THE AREA DOES RISES SOME CONCERN FOR HEAVY RAINFALL AS IT
MOVES THROUGH. PRECIPITABLE WATER (PWAT) VALUES WILL BE NEARING
THE CLIMATOLOGICAL MAX OF 1.19" FOR APRIL. MODELED PWATS FROM
THE GFS AND RAP RANGE FROM 1.00" TO 1.15", EMPHASIZING THE
MOISTURE AVAILABLE. THIS MOISTURE WILL BE FUELED BY THE
INCREASING LLJ THIS EVENING, BEFORE THE SHORTWAVE PUSHES THE
MOISTURE SOUTHEASTWARD EARLY FRIDAY MORNING. FORECAST RAINFALL
AMOUNTS ARE GENERALLY AROUND AN INCH TO INCH AND HALF FOR MUCH
OF THE AREA AND RATES DON'T APPEAR OVERLY HIGH (GENERALLY AROUND
0.25" TO 0.50" PER HOUR) WHICH SHOULD HELP MINIMIZE FLASH
FLOODING CONCERNS. HOWEVER, AS SUGGESTED IN THE PRIOR
DISCUSSION, HIGH RESOLUTION MODELS DO SUGGEST THERE COULD BE A
NARROW CORRIDOR OF HIGHER RAINFALL AMOUNTS JUST FROM THE
PROLONGED NATURE OF THE RAINFALL. HREF PROBABILITY MATCHED MEAN
QPF OUTPUT THROUGH FRIDAY MORNING PAINTS THIS SWATH ROUGHLY
AROUND THE INTERSTATE 80 TO US HIGHWAY 30 CORRIDORS, WITH A
BULLSEYE OF 3"+ RAINFALL. IF THIS FALLS IN THE WRONG BASINS,
THIS MAY LEAD TO SOME LOCALIZED STREAM FLOODING. MORE ON THE
HYDROLOGICAL/RIVER CONCERNS IN THE HYDRO SECTION.
BY FRIDAY MORNING, THE SHORTWAVE WILL HAVE PUSHED THE SURFACE AND
ELEVATED BOUNDARIES TO OUR SOUTH AND EAST, LEAVING IOWA WITH A
PERIOD OF HIGH PRESSURE AND DRIER CONDITIONS THROUGH FRIDAY.
TEMPERATURES WILL REMAIN MILD WITH SKIES CLEARING OUT IN THE
AFTERNOON.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 246 PM CDT THU APR 9 2026
FRIDAY'S DRY SPELL WILL BE RELATIVELY SHORT-LIVED, AS THE UPPER
LEVEL PATTERN TRANSITIONS TO A SOUTHWESTERLY FLOW REGIME. THIS WILL
OPEN THE MIDWEST UP TO A STRONG GULF MOISTURE STREAM, LEADING TO
MULTIPLE DAYS OF RAIN AND THUNDERSTORM CHANCES. THE FIRST, AND MOST
IMMEDIATE, OF THESE CHANCES WILL BEGIN LATER SATURDAY AS THE GULF
MOISTURE INITIALLY ARRIVES. RECALL THE CLIMATOLOGICAL MAX PWAT
VALUES FOR OF AROUND 1.18", AS THIS GULF MOISTURE STREAM
ARRIVES, THE GFS FORECAST PWAT VALUES WILL SKYROCKET UP TO NEAR
1.50" SATURDAY INTO SUNDAY, WHICH IS MORE COMPARABLE TO VALUES
WE WOULD TYPICALLY SEE IN THE SUMMER MONTHS. FORTUNATELY, THERE
WON'T BE ANY ROBUST LARGE-SCALE FEATURES ACCOMPANYING THIS
MOISTURE PLUME SATURDAY INTO SUNDAY, MEANING MOST OF THIS
PRECIPITATION WILL BE DRIVEN BY LOW LEVEL THETA-E ADVECTION AND
A RATHER STRONG LOW-LEVEL JET. WITH THE WEAKER FORCING, QPF
AMOUNTS AT THIS TIME RANGE DON'T LOOK OVERLY CONCERNING,
GENERALLY AROUND A HALF INCH TO AN INCH. LIKEWISE, THERE WILL BE
MINIMAL SEVERE WEATHER THREAT, GIVEN THE LACK OF ANY STRONG
KINEMATICS OR EVEN THERMODYNAMICS. THEREFORE, ASIDE FROM
OCCASIONAL THUNDER, THE MAIN CONCERN THIS WEEKEND LOOKS LIKE IT
WILL BE YET ANOTHER WIDESPREAD HEAVY RAIN EVENT AND MORE LIQUID
ROUTING INTO OUR RIVERS AND STREAMS.
MORE RAIN AND THUNDERSTORM CHANCES CONTINUE INTERMITTENTLY SUNDAY
THROUGH THE BEGINNING OF NEXT WEEK WITH SEVERE POTENTIAL THROUGHOUT
THAT PERIOD. THERE HAS BEEN QUITE A BIT OF VARIABILITY FROM SUNDAY
AND BEYOND GIVEN THE LACK OF ANY PROMINENT SYNOPTIC FEATURES UNTIL
AROUND THE TUESDAY INTO WEDNESDAY TIMEFRAME. THEREFORE, THE BROAD
TAKEAWAY AT THIS TIME IS AN ACTIVE PATTERN WITH SOME SEVERE WEATHER
POTENTIAL CONTINUING INTO NEXT WEEK. ASIDE FROM THE PRECIPITATION,
TEMPERATURES ALSO WARM QUITE A BIT INTO EARLY NEXT WEEK AS THIS
PATTERN ADVECTS WARMER, MOIST AIR UP INTO THE STATE.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1224 PM CDT THU APR 9 2026
RAIN HAS STARTED TO SPREAD ACROSS SOUTHERN IOWA EARLY THIS
AFTERNOON, IMPACTING KOTM AND KDSM WITHIN THE NEXT FEW HOURS.
THIS RAINFALL IS EXPECTED TO PERSIST AND EXPAND THROUGH THE REST
OF THE AFTERNOON AND EVENING, IMPACTING ALL SITES AT SOME POINT
THROUGH THE NEXT 12 HOURS. A FEW THUNDERSTORMS ARE ALSO
POSSIBLE, MAINLY OVER SOUTHERN INTO CENTRAL IOWA, BUT AREN'T
EXPECTED TO BE WIDESPREAD OR PERSISTENT. THEREFORE, HAVE ONLY
INCLUDED PROB30 MENTION FOR THE MOST LIKELY PERIOD AT KDSM AND
KOTM. MVFR TO IFR VISIBILITIES WILL ACCOMPANY THIS ACTIVITY
THROUGH THE EVENING AND EARLY MORNING HOURS BEFORE DRIER AIR
BEGINS TO IMPROVE CEILINGS THROUGH FRIDAY MORNING.
HYDROLOGY
ISSUED AT 248 PM CDT WED APR 8 2026
RAINFALL TONIGHT INTO EARLY FRIDAY MORNING WILL GENERALLY BE IN THE
0.5" TO 1.5" RANGE, WITH SOME LOCALLY HIGHER AMOUNTS OF 2 TO 3"
RAINFALL POSSIBLE. THE BULK OF THE RAINFALL WILL BE OVER SOUTHERN
INTO CENTRAL IOWA, WHICH IS WHERE CAPACITY IS THE BEST. WHILE FLASH
FLOODING IS NOT ANTICIPATED, LOCAL RIVER RISES ARE POSSIBLE,
ESPECIALLY IF THIS HEAVIER SWATH FALLS OVER ANY SMALLER CREEK
BASINS. THEREFORE, WHILE THE RISK FOR FLOODING ISN'T HIGH, THE
LOCATION OF THE HEAVIEST RAINFALL WILL NEED TO BE MONITORED THIS
EVENING. AS WE GET INTO THE WEEKEND, MORE WIDESPREAD RAINFALL IS
POSSIBLE SATURDAY INTO SUNDAY, WITH FORECAST AMOUNTS GENERALLY
AROUND AN INCH OR LESS. THE CURRENT LOCATION FOR THE HIGHEST QPF IS
CURRENTLY OVER WESTERN IOWA WHERE RIVERS AND SOILS HAVE MORE
CAPACITY, BUT WILL WANT TO WATCH FOR AN EASTERLY SHIFT CLOSER TO
AREAS THAT HAVE LESS CAPACITY. EITHER WAY, RAIN ON SATURDAY INTO
SUNDAY WILL SET THE STAGE FOR WHAT'S EXPECTED TO BE AN ACTIVE WEEK
NEXT WEEK. QPF AMOUNTS AND LOCATIONS NEXT WEEK ARE STILL UNCERTAIN,
BUT THE WETTER TREND WITH SUCCESSIVE RAIN EVENTS CERTAINLY RAISES
CONCERNS FOR INCREASED RIVER LEVELS NEXT WEEK.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...DODSON
LONG TERM...DODSON
AVIATION...DODSON
HYDROLOGY...DODSON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page