394
FXUS63 KDMX 011948
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
248 PM CDT WED APR 1 2026
KEY MESSAGES
- SHOWERS WILL EXPAND ACROSS THE STATE THROUGH THIS AFTERNOON
INTO THE EVENING, CONTINUING OVERNIGHT INTO THURSDAY.
WIDESPREAD 1-2+" OF RAIN EXPECTED ACROSS IOWA BY THURSDAY
EVENING.
- STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE IN IOWA THURSDAY
AFTERNOON, MAINLY OVER SOUTHERN AND EASTERN IOWA. ALL SEVERE
HAZARDS ARE POSSIBLE.
- ADDITIONAL SEVERE STORMS ON FRIDAY. AN ENHANCED RISK (LEVEL 3
OF 5) IS IN PLACE FOR CENTRAL AND SOUTHERN IOWA. ALL SEVERE
HAZARDS ARE POSSIBLE.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 240 PM CDT WED APR 1 2026
RELATIVELY BENIGN CONDITIONS ARE NOTED ACROSS CENTRAL IOWA SO FAR
TODAY, WITH MOST AREAS SEEING MOSTLY CLOUDY SKIES AS A SHORTWAVE
PASSES OVERHEAD. TEMPERATURES HAVE WARMED INTO THE 40S ACROSS THE
STATE, WHICH MAY WARM A FEW DEGREES YET IN SOME SPOTS BUT WILL
OTHERWISE REMAIN ON THE COOLER SIDE FOR THE REST OF TODAY. PATCHY
AND LIGHT RETURNS ARE SEEN ON RADAR THIS AFTERNOON, THOUGH
CONDITIONS PER SURFACE OBSERVATIONS HAVE REMAINED DRY. COULD SEE
PERIODS OF RELATIVELY LIGHT RAIN AS THESE PATCHY WEAK SHOWERS LIFT
NORTHEAST THROUGH THE REMAINDER OF THE AFTERNOON. SURFACE
CYCLOGENESIS ON THE LEE SIDE OF THE ROCKIES IS EXPECTED TO OCCUR
THIS EVENING, DEVELOPING THE SYSTEM THAT WILL ULTIMATELY DRIVE THE
ACTIVE FORECAST THROUGH THURSDAY WITH THIS LOW PRESSURE MOVING
ACROSS THE MIDWEST. IN THE MEANTIME THOUGH, SHOWERS AHEAD OF THIS
SYSTEM ARE STILL EXPECTED TO EXPAND IN COVERAGE NORTHEASTWARD ACROSS
IOWA INTO THIS EVENING. LATEST CAM GUIDANCE CONTINUES TO SHOW THIS
SCATTERED SHOWER ACTIVITY WELL NORTH OF THE SURFACE WARM FRONT,
WHICH INTO LATE THIS EVENING IS ORIENTED WEST TO EAST OVER NORTHERN
MISSOURI. GIVEN THIS LOCATION OF THE SURFACE FEATURE, AND THE BULK
OF BETTER FORCING FROM THE INCREASING LOW LEVEL JET CONCENTRATED
OVER MISSOURI, THE OVERALL POTENTIAL FOR STORM COVERAGE INTO
SOUTHERN IOWA LOOKS FAIRLY LOW. A CLOSER LOOK AT SOUNDINGS SHOWS
DEEP LIFT ASSOCIATED WITH A STRONG LOW LEVEL JET AND SATURATION
THROUGH THE COLUMN AS MOISTURE SURGES NORTHWARD, BRINGING PWAT
VALUES AROUND 1.25-1.5 INTO THE STATE. RAINFALL THEREFORE WILL BE
QUITE EFFICIENT AND WIDESPREAD, WITH PERIODS OF HEAVY RAIN AS
THIS ACTIVITY LIFTS NORTH ACROSS THE STATE THROUGH THE MORNING,
WITH THE POTENTIAL FOR AREAS OF PONDING AND EVEN SOME MINOR
FLOODING, ESPECIALLY IN LOW-LYING AREAS. PLEASE SEE THE SPECIFIC
HYDROLOGY SECTION FURTHER BELOW FOR ADDITIONAL DETAILS. IN
TERMS OF STORM POTENTIAL INTO IOWA, CANNOT RULE OUT A FEW
ELEVATED WEAK STORMS INTO SOUTHERN IOWA TONIGHT INTO THURSDAY AS
A NOTABLE INVERSION SETS UP, PAIRED WITH RATHER LIMITED
INSTABILITY OVERHEAD. SHOWER AND STORMS ARE EXPECTED TO CONTINUE
THROUGH THURSDAY MORNING, WITH THIS BOUNDARY EXPECTED TO LIFT
INTO FAR SOUTHERN IOWA AROUND OR JUST AFTER SUNRISE, WITH MUCH
OF THE ACTIVITY EXPECTED TO REMAIN GENERALLY OVER CENTRAL TO
NORTHERN IOWA THROUGH THE REMAINDER OF THE MORNING, WITH
EMBEDDED NON-SEVERE STORMS POSSIBLE.
AS THE SURFACE LOW CONTINUES TO DEEPEN AS IT QUICKLY PIVOTS
NORTHEASTWARD ACROSS IOWA IN THE MORNING, THIS INITIAL ROUND OF
SHOWERS/STORMS WILL DECREASE IN COVERAGE BY LATE MORNING AS THE
WARM FRONT QUICKLY MOVES NORTHEASTWARD, ALLOWING FOR A PERIOD
OF SOME DRYING TO OCCUR FOR MUCH OF THE AREA. WARM AND MOIST AIR
IS PROGGED TO LIFT INTO THE STATE INTO THE AFTERNOON AS WELL,
ESPECIALLY OVER SOUTHERN AND EASTERN IOWA WHERE HIGHS ARE
EXPECTED TO TOP OUT INTO THE 60S TO LOW 70S. WHILE THERE ARE
SOME MINOR VARIATIONS IN GUIDANCE, THE GENERAL TRENDS SHOW A
COLD FRONT ARRIVING OVER THE WESTERN PORTION OF THE FORECAST
AREA, AS THE SYSTEM TRACKS DIRECTLY OVER CENTRAL IOWA, WITH THIS
FRONT SURGING EASTWARD ACROSS THE STATE THROUGH THE AFTERNOON
BEFORE DEPARTING EAST OUT OF THE AREA BY THE EARLY EVENING.
ADDITIONAL SHOWERS AND STORMS ARE EXPECTED TO DEVELOP AHEAD OF
THIS BOUNDARY ROUGHLY AFTER 12-1PM, WITH RELATIVE FAST STORM
MOTIONS AS THEY RACE NORTHEASTWARD THROUGH ABOUT 5-6PM. A DIVE
INTO THE MESOSCALE ENVIRONMENT DURING THE AFTERNOON SHOWS
INCREASING INSTABILITY VALUES AROUND 1000+ J/KG, ALONG WITH BULK
SHEAR VALUES AROUND 35+ KNOTS. THE INDICATION OF DRY AIR IN THE
LOW LEVELS AND STEEP LAPSE RATES WOULD POINT TO HAIL AND
DAMAGING WINDS FOR THREATS OVER SOUTHERN AND EASTERN IOWA,
THOUGH A FEW TORNADOES CANNOT BE RULED OUT WHERE CURVING
HODOGRAPHS ARE NOTED. A SLIGHT RISK AREA PER SPC NOW EXTENDS
INTO PARTS OF EAST CENTRAL TO EASTERN IOWA. SOME UNCERTAINTY IS
IN PLAY REGARDING THE EXTENT OF SEVERE STORMS DEVELOPMENT, SINCE
LINGERING CLOUD COVER FROM THE MORNING CONVECTION COULD LIMIT
CLEARING POTENTIAL THAT WOULD BE IDEAL FOR SUPERCELL POTENTIAL,
SO SOMETHING TO WATCH THROUGH THE DAY. REGARDLESS OF WHETHER
STRONG/SEVERE STORMS DEVELOP, INCREASING SYNOPTIC WINDS OVER
SOUTHERN AND EASTERN IOWA WILL OCCUR AHEAD OF THE COLD FRONT,
WITH GUSTS EXPECTED TO PUSH 35-40+ MPH AT TIMES, THOUGH SHOULD
DIMINISHING THROUGH THE EVENING.
NORTHWEST WINDS ARE EXPECTED TO PUSH THROUGH THE STATE THURSDAY
EVENING, WHICH WILL BRING COOLER AIR OVERHEAD INTO FRIDAY. OVERNIGHT
LOW ARE EXPECTED THROUGH THE 30S TO MID 40S, WARMEST SOUTH.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 240 PM CDT WED APR 1 2026
THE PATTERN REMAINS QUITE ACTIVE TO END THE WORK WEEK, AS ANOTHER
TROUGH MOVES ACROSS THE WESTERN CONUS AND LEE SIDE CYCLOGENESIS
OCCURS OFF THE ROCKIES ONCE AGAIN, PRODUCING AN EVEN MORE POTENT LOW
PRESSURE SYSTEM THAT IS FORECAST TO TRACK EASTWARD INTO THE CENTRAL
PLAINS. THIS SURFACE LOW IN RELATION TO THE PREVIOUS SYSTEM IS A BIT
FURTHER SOUTH IN COMPARISON, BUT IS EXPECTED TO SHARPLY PIVOT UP
THROUGH IOWA BY THE LATE AFTERNOON TO EVENING. WHILE DRY CONDITIONS
ARE EXPECTED AT LEAST THROUGH THE MORNING, WARM AND MOIST AIR
QUICKLY LIFTS INTO IOWA THROUGH THE AFTERNOON, ESPECIALLY SOUTHWARD
OF I-80, WITH FORECAST HIGHS EXPECTED TO TOP OUT INTO THE UPPER 40S
TO 50S OVER ROUGHLY THE NORTHERN HALF OF THE STATE, AND IN THE 60S
TO LOW 70S OVER THE SOUTHERN HALF. THE MAIN FOCUS AREA HOWEVER WILL
COME LATE AFTERNOON TO EVENING AS A RATHER STRONG COLD FRONT ARRIVES
INTO WESTERN IOWA, TRACKING EASTWARD ACROSS THE STATE. THE
ENVIRONMENTAL PARAMETER SPACE OVER THE WARM SECTOR LOOKS TO BE QUITE
CONDUCIVE FOR POTENTIAL SEVERE WEATHER, WITH VERY UNSTABLE
CONDITIONS GIVEN VALUES OF 2000+ J/KG OF CAPE, BULK SHEAR VALUES OF
40-45+ KNOTS, AND SRH VALUES OVER 300 M2/S2, WITH ALL MODES OF
SEVERE WEATHER POSSIBLE. THE ENHANCED RISK AREA PER SPC REMAINS
SOUTH OF I-80 GIVEN THE MORE FAVORABLE SETUP. DETAILS REGARDING
OVERALL EXPECTATIONS WILL BECOME MORE CLEAR OVER THE NEXT FEW DAYS.
THE DRY SLOT ARRIVES INTO SATURDAY FOLLOWING THE DEPARTING COLD
FRONT, WITH NORTHWEST SPREADING ACROSS IOWA THROUGH THE DAY THAT
WILL LEAD TO NOTABLY COOLER TEMPERATURES AND BREEZY CONDITIONS.
GUIDANCE INDICATES WRAP AROUND PRECIPITATION ON THE COLD SIDE OF THE
DEEPENING LOW AS IT CONTINUES TO NORTHEASTWARD, THOUGH TRENDS KEEP
MOST IF NOT ALL OF THIS ACTIVITY GENERALLY ALONG AND NORTH OF THE
IA/MN BORDER. CERTAINLY SOMETHING TO WATCH AS A SOUTHERN TREND COULD
MEAN THE INTRODUCTION OF AT LEAST SOME WINTERY MIX TO EXTEND INTO
NORTHERN IOWA.
A BUILDING RIDGE INTO EARLY NEXT WEEK SUGGEST GENERALLY QUIETER
CONDITIONS OVER IOWA, WITH MAINLY QUIET WEATHER AND NORTHWEST
FLOW.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1241 PM CDT WED APR 1 2026
EXPECT AVIATION CONDITIONS TO DETERIORATE FROM SOUTH TO NORTH
THIS AFTERNOON INTO TONIGHT. CURRENT MVFR/IFR CEILINGS IN FAR
SOUTHERN IOWA WILL PUSH NWD, IMPACTING OTM/DSM FROM 21Z-00Z, AND
NORTHERN TERMINALS BETWEEN 03Z-06Z. IN ADDITION, RAIN SHOWERS
WILL INCREASE IN COVERAGE AND INTENSITY THIS EVENING INTO
TONIGHT WITH MVFR, TO OCCASIONAL IFR VSBYS. WHILE INSTABILITY
WILL BE MODEST OVERNIGHT, EMBEDDED THUNDERSTORMS ARE POSSIBLE AT
OTM/DSM, AND MAINTAINED THE PROB30 TO ACCOUNT FOR THIS THREAT.
WINDS DURING THIS PERIOD WILL REMAIN EASTERLY /15-30KTS/.
A SECOND ROUND OF THUNDERSTORMS IS POSSIBLE TOWARDS THE END OF
THE TAF PERIOD, AFTER 15Z, SOME OF THESE STORMS COULD BECOME
STRONG TO SEVERE. MORE DETAILS IN FUTURE UPDATES.
HYDROLOGY
ISSUED AT 130 PM CDT TUE MAR 31 2026
CONTINUED SHORT AND LONG TERM FLOODING CONSIDERATIONS EXIST DUE TO
THE IMMINENT MULTI-DAY SEASONALLY MODERATE TO HEAVY RAINFALL EVENT,
MAINLY ACROSS THE SOUTHEAST HALF OF THE CWA.
SHORT TERM CONSIDERATIONS INCLUDE POTENTIAL PONDING AND LOW-END
FLASH FLOODING. SOIL MOISTURE VALUES ARE GENERALLY RUNNING NEAR TO
BELOW NORMAL. THAT DATA COMBINED WITH THE QPF SUGGESTS ANY PONDING
AND FLASH FLOODING WILL BE MAINLY RATE VS. AMOUNT DRIVEN, WITH THE
GREATEST RISK IN URBAN AREAS.
LONGER TERM CONSIDERATIONS INCLUDE POTENTIAL RIVER FLOODING. GFS-
AND NBM-FORCED NATIONAL WATER MODEL, HEFS AND QPF ENSEMBLE
HYDROGRAPHS INDICATE THE MOST LIKELY SCENARIO WILL BE MODERATE TO
SIGNIFICANT WITHIN-BANK RISES. A FEW LOCATIONS MAY REACH FLOOD
STAGE, HOWEVER MINOR FLOODING WOULD BE EXPECTED AT MOST IF IT
OCCURS. THE PEAKS ON MOST RIVERS WILL OCCUR THIS WEEKEND INTO EARLY
NEXT WEEK. GREATER CONCERN IS THE NEXT FEW DAYS OF RAINFALL MAY SET
THE STAGE FOR MORE SIGNIFICANT IMPACTS GOING FORWARD IF THE WET
PATTERN CONTINUES.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...BURY
LONG TERM...BURY
AVIATION...FOWLE
HYDROLOGY...ZOGG
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