472
FXUS63 KDMX 091156
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
656 AM CDT THU APR 9 2026
...UPDATED FOR THE 12Z AVIATION DISCUSSION...
KEY MESSAGES
- COOLER OVER MUCH OF IOWA TODAY. SHOWER AND STORM CHANCES
INCREASING THROUGH THE DAY, ESPECIALLY THIS AFTERNOON INTO
TONIGHT OVER SOUTHERN AND CENTRAL IOWA. A STRONGER STORM AND
ISOLATED HEAVY RAINFALL IS POSSIBLE.
- MAINLY DRY PERIOD FROM FRIDAY MORNING INTO SOME PART OF
SATURDAY MORNING.
- ACTIVE PATTERN REMAINS ON TRACK FROM THIS WEEKEND INTO ABOUT
THE MIDDLE OF NEXT WEEK WITH SEVERAL ROUNDS OF STORMS
EXPECTED, WHICH COULD LEAD TO ONE OR MORE EPISODES OF SEVERE
STORMS AND HEAVY RAINFALL. TRENDS WILL CONTINUED TO BE
MONITORED.
- TEMPERATURES MAINLY ABOVE NORMAL SATURDAY INTO THE MIDDLE OF NEXT
WEEK.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 253 AM CDT THU APR 9 2026
GOES-EAST UPPER LEVEL WATER VAPOR IMAGERY IS QUITE STUNNING
EARLY THIS MORNING SHOWING A VERY WOUND UP, CYCLONIC SPIN THAT
HAS BEEN TREKKING ALONG THE US/CANADIAN BORDER AND IS JUST PAST
THE ARROWHEAD OF MINNESOTA. AT THE SURFACE, A COLD FRONT HAS
CLEARED ALL OF IOWA WITH LOW LEVEL COLD AIR ADVECTION ONGOING
BEHIND THE FRONT. THIS BOUNDARY WILL NOT MOVE MUCH FROM WHERE IT
IS NOW NEAR THE IOWA MISSOURI BORDER AND WILL SERVE AS A FOCUS
FOR RENEWED SHOWER AND LATER STORM DEVELOPMENT AS STRONG THETA-E
ADVECTION INTERACTS WITH THIS STALLED BOUNDARY. THESE CHANCES
WILL BE HIGHEST OVER SOUTHERN AND CENTRAL IOWA, ESPECIALLY THIS
AFTERNOON INTO TONIGHT. FORECAST SOUNDINGS CONTINUE TO POINT TO
STORMS BEING ELEVATED AND AM STRUGGLING TO SEE MUCH SEVERE RISK
WITH THIS SETUP. THE HRRR AND RRFS SOUNDINGS SHOW A BIT OF
DRIER SUBCLOUD LAYER WITH SATURATION ALOFT INITIALLY, WHICH
QUICKLY SATURATES WITH THE NAM, GFS, AND RAP SOUNDINGS JUST
SATURATED. MUCAPE VALUES PUSH TO 500 TO MAYBE 750 J/KG AND THE
EFFECTIVE SHEAR IS MORE MESSY THAN PREVIOUS RUNS. MID-LEVEL
LAPSE RATES MAY ALSO NOT BE QUITE AS GOOD AND WITH THE SATURATED
PROFILE, WOULD GENERALLY EXPECT HAIL SIZE TO BE NO LARGER THAN
QUARTER SIZED AND GENERALLY SMALLER. AS FOR WIND GUST POTENTIAL,
DESPITE MEAGER DOWNDRAFT CAPE VALUES AND THE SATURATED PROFILE,
THE 0Z HRRR DID PRODUCE TWO, SUB-SEVERE WIND GUST AREAS OF 35
TO 45 KNOTS OVER SOUTHERN IOWA, WHICH IS NOT REFLECTED IN THE 6Z
RUN. SO WHILE I CANNOT COMPLETELY DISCOUNT AN ISOLATED SEVERE
STORM OR TWO, THINK THE BULK IF NOT ALL OF THE ACTIVITY WILL BE
SUB-SEVERE. WILL ALSO BE KEEPING AN EYE ON HEAVY RAINFALL
POTENTIAL TONIGHT AS PRECIPITABLE WATER VALUES WILL BE WELL
ABOVE NORMAL AND WARM CLOUD DEPTHS WILL BE SEASONAL. WHILE
DETERMINISTIC MODELS PRODUCE AMOUNTS OF 1 TO 1.5 INCHES OVER
PORTIONS OF CENTRAL AND SOUTHERN IOWA, THE LATEST HREF LOCALIZED
PROBABILITY MATCHED MEAN SHOWS SWATHS OF 2 TO 3 INCHES BETWEEN
I-80 AND US 34. RAIN RATES OF A QUARTER TO HALF AN INCH PER HOUR
MAY MITIGATE LARGER CONCERNS, BUT IF THESE HIGHER TOTALS FALL
OVER AN URBAN AREA, THEY COULD SPELL WATER ISSUES. OTHERWISE,
SOILS OVER IOWA HAVE RECOVERED FROM LAST WEEK WITH 0-10 AND
0-40CM SOIL MOISTURE PERCENTILES NORMAL (30-70TH) OR LOWER
POINTING TO CAPACITY TO HANDLE THIS ROUND OF RAINFALL. RFC
CONTINGENCY FORECASTS BASED ON EXPECTED RAINFALL SHOW MAINLY WITHIN
BANK RISES IN SOUTHERN IOWA.
SURFACE HIGH PRESSURE WILL PUSH INTO IOWA LATER THURSDAY NIGHT INTO
FRIDAY PUSHING THE FRONT AND RAINFALL AWAY FROM THE STATE, WHICH
SHOULD LAST ANYWHERE FROM 24 TO 36 HOURS DEPENDING ON WHERE ONE
IS LOCATED IN THE STATE.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 253 AM CDT THU APR 9 2026
AN ACTIVE PATTERN WITH MULTIPLE ROUNDS OF THUNDERSTORMS ARE FORECAST
FROM THIS WEEKEND TO ABOUT THE MIDDLE OF NEXT WEEK. THIS PATTERN
WILL BE DRIVEN BY A WESTERN CONUS TROUGH THAT WILL PROMOTE
SOUTHWESTERLY FLOW OVER THE REGION. THE FIRST CHANCE FOR STORMS
TO RETURN WILL BE SATURDAY AS STRONG THETA-E ADVECTION PUSHES
ACROSS THE STATE WITH RICH GULF MOISTURE STREAMING INTO THE
AREA. THERE IS NO STRONG SIGNAL FOR SEVERE WEATHER ON SATURDAY
GIVEN OVERALL MEAGER INSTABILITY AND NAM AND GFS SOUNDINGS THAT
LOOK RATHER SATURATED. THESE SATURATED PROFILES DO PRODUCE
PRECIPITABLE WATER VALUES NEAR THE 99TH PERCENTILE, THOUGH
DETERMINISTIC MODELS ONLY SHOW 24 HOUR TOTALS OF AROUND AN INCH
WITH NBM 90TH PERCENTILE TOTALS NEARING 1.5 INCHES. THESE TOTALS
MAY BE DUE TO RATHER FAST 850-300MB FLOW OF 30 KNOTS. SUNDAY
WILL BE BREEZY AND WARM WITH HIGHS WELL ABOVE NORMAL AND LIKELY
IN THE 70S. THE NEXT ROUND OF STORMS IS ALSO POSSIBLE ON THIS
DAY AS HIGHER KINEMATICS MOVE INTO THE REGION WITH A LEAD
SHORTWAVE TROUGH AHEAD OF THE MAIN TROUGH PASSES NORTHWEST OF
THE STATE. THERE IS THE POSSIBILITIY OF STRONG TO PERHAPS SEVERE
WEATHER AS THERE WILL BE HIGHER INSTABILITY WITH MORE MODEST
DEEP LAYER SHEAR. AS THE WESTERN CONUS TROUGH BEGINS TO MOVE
TOWARD THE REGION EARLY NEXT WEEK, MONDAY AND TUESDAY MAY
PRODUCE STRONG TO SEVERE STORMS AND HEAVY RAINFALL AND TRENDS IN
BOTH WILL HAVE TO BE MONITORED.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 649 AM CDT THU APR 9 2026
VFR CONDITIONS PREVAIL FOR THE NEXT SEVERAL HOURS BEFORE SHOWERS AND
THUNDERSTORMS MOVE ACROSS THE REGION. SHOWERS FORM LATE MORNING IN
CENTRAL AND SOUTHERN IOWA AND MOVE TOWARDS THE NORTHERN SITES BY
EARLY AFTERNOON, EVENTUALLY USHERING IN MVFR CIGS. SHOWERS INTENSIFY
THROUGH THE DAY AND BECOME STORMS BY EVENING AT KDSM/KALO/KOTM, AND
PERHAPS KFOD IF CONFIDENCE IMPROVES. THESE STORMS ARE EXPECTED TO BE
WIDESPREAD, AND FUTURE UPDATES MAY NEED PREVAILING TSRA. STORMS WILL
BRING IN LOWERED VISIBILITY AND LIKELY CROSS IFR CIG THRESHOLDS AT
KDSM/KOTM SITES. CIGS IMPROVE NEAR THE END OF THE TAF PERIOD.
HYDROLOGY
ISSUED AT 1130 AM CDT WED APR 8 2026
RAINFALL UP TO 1-2" IS EXPECTED IN SOUTHERN IOWA WITH THE
BOUNDARY HUNG UP ACROSS CENTRAL AND SOUTHERN IOWA THURSDAY INTO
EARLY FRIDAY MORNING. SOUTHERN IOWA HAS CAPACITY FOR MOISTURE
GIVEN EARLIER PRECIPITATION THAT LARGELY MISSED THAT PART OF THE
STATE, BUT IT WILL SET THE STAGE FOR POSSIBLE IMPACTS FROM
LATER ROUNDS OF RAIN. BY SATURDAY AND SUNDAY ANOTHER WIDESPREAD
1+" WILL FALL ACROSS THE STATE WITH HIGHER 2+" POCKETS POSSIBLE.
THE FIRST HALF OF NEXT WEEK REMAINS ACTIVE WITH ADDITIONAL RAIN
POSSIBLE. HEFS 10 DAY PROBABILITY OF EXCEEDANCE NOTES THAT MANY
SITES HAVE 50% CHANCES FOR REACHING ACTION. GOING UP TO THE 10%
CHANCE OF EXCEEDANCE BRINGS A HANDFUL OF SITES REACHING MINOR
FLOOD. EXACT QPF AMOUNTS AND PLACEMENT WILL HAVE NOTABLE
DIFFERENCES TO IMPACT AND THE FORECAST WILL CONTINUE TO BE FINE
TUNED OVER THE NEXT SEVERAL DAYS.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...ANSORGE
LONG TERM...ANSORGE
AVIATION...ANSORGE/DE BRUIN
HYDROLOGY...HAGENHOFF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page