627
FXUS63 KDMX 020809
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
309 AM CDT THU APR 2 2026
KEY MESSAGES
- SHOWERS CONTINUE THROUGH THIS MORNING. SEVERE THUNDERSTORMS
IN CENTRAL TO EASTERN IOWA THIS AFTERNOON. ALL SEVERE HAZARDS
ARE POSSIBLE.
- SEVERE STORMS FRIDAY AFTERNOON AND EVENING IN SOUTHERN HALF
OF IOWA WITH A ENHANCED RISK (LEVEL 3 OF 5) FOR SEVERE STORMS.
ALL SEVERE HAZARDS ARE POSSIBLE.
- COOLER AND QUITE THIS WEEKEND, COULD BECOME ACTIVE AGAIN LATER
NEXT WEEK.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 309 AM CDT THU APR 2 2026
SURFACE LOW PRESSURE SITS ACROSS WESTERN KANSAS EARLY THIS MORNING
BROAD LIFT ACROSS IOWA AND THE 850 MB LLJ NOSING UP INTO SOUTHERN
IOWA. THIS HAS ALLOWED FOR WIDESPREAD SHOWERS TO PERSIST THROUGH THE
OVERNIGHT ALONG WITH A FEW EMBEDDED RUMBLES OF THUNDER. THAT LLJ
WILL INCREASE TO 50-60+ KTS AND PUSH INTO IOWA THROUGH THIS MORNING,
HELPING TO MAINTAIN SHOWERS ACROSS THE AREA, ENDING WEST TO EAST
MIDDAY AS THE SURFACE LOW LIFTS INTO IOWA. AS THE LOW TRACKS ACROSS
IOWA THIS AFTERNOON A DRY SLOT WILL DEVELOP, ALLOWING FOR DEEPER
MIXING AND DEEP INSTABILITY DEVELOPMENT WHERE WE GET CLEARING.
ENVIRONMENTAL WINDS INCREASE IN THIS SLOT WITH HREF MEAN GUSTS OF 35-
40+ MPH GUSTS IN SOUTHEAST IOWA. SOUNDINGS INDICATE PERIODS OF 40-
50+ KTS AT THE TOP OF THE MIXED LAYER IN SOUTHEAST IOWA, WHICH MAY
ALLOW FOR AN OCCASIONAL STRONGER GUST THIS AFTERNOON. CONDITIONS ARE
BETTER EAST OF THE AREA INTO THE QUAD CITIES CWA WHERE THE WIND
ADVISORY HAS BEEN ISSUED.
THE SURFACE LOW REACH SOUTH-CENTRAL IOWA BY AROUND 18Z AND
PUSHES TO EASTERN IOWA BY AROUND 23Z WHICH WILL DEFINE THE
NARROW WINDOW FOR SEVERE STORMS HERE. INSTABILITY IN THAT CLEAR
SLOT IS EXPECTED TO INCREASE TO 1000-1500 J/KG OF MLCAPE ALONG
WITH ~40 KTS OF 0-6 KM SHEAR WHICH IS MORE THAN SUFFICIENT FOR
CONVECTIVE INITIATION. MID LEVEL LAPSE RATES ARE AROUND 7 C/KM
ALONG WITH 150 M2/S2 0-1 KM SRH. EXPECT THAT STORMS WILL
INITIALIZE IN CENTRAL IOWA EARLY THIS AFTERNOON AND QUICKLY
MOVE EAST THROUGH THE AFTERNOON. INITIAL DISCRETE TO MULTICELL
CLUSTERS IN CENTRAL IOWA GROWING UPSCALE AS THEY MOVE INTO
EASTERN IOWA. ALL MODES OF SEVERE WEATHER ARE POSSIBLE INCLUDING
LARGE HAIL, DAMAGING WIND GUSTS, AND TORNADOES. THE TORNADO
THREAT SHOULD BE MAXIMIZED IN THE VICINITY OF THE SURFACE LOW
AND WITH INITIAL DISCRETE STORM MODE.
ANOTHER UPPER LEVEL WAVE WILL AMPLIFY AS IT IT MOVE FROM THE WESTERN
TO CENTRAL US ON FRIDAY. THE LOW TRACK REMAINS FAIR CONSISTENT
ACROSS GFS AND EC ENSEMBLE MEMBERS, MOVING SW TO NE ACROSS IOWA
THROUGH THE AFTERNOON, FED BY A 50+ KT LLJ. INSTABILITY BUILDS
THROUGH THE AFTERNOON WITH 2000+ J/KG MLCAPE AND 40-50 KTS OF
0-6 KM SHEAR TO ORGANIZE STORMS. AGAIN ANTICIPATE INITIAL
DISCRETE DEVELOPMENT, GROWING UPSCALE AS IT MOVES INTO EASTERN
IOWA. THESE CELLS MAY REMAIN DISCRETE LONGER THAN THE THURSDAY
STORMS, AND CAMS INDICATE A LINE OF SUPERCELLS ACROSS CENTRAL
IOWA BEFORE THE LINE-OUT INTO EASTERN IOWA. THIS EVOLUTION IS
SUPPORTED BY THE EXPECTED MESOSCALE ENVIRONMENT. LAPSE RATES
STEEPEN TO 8 C/KM IN THE MID LEVELS WITH 300+ M2/S2 OF 0-1 KM
SRH. AS SUCH, ONCE AGAIN EXPECT ALL MODES OF SEVERE STORMS ON
FRIDAY INCLUDING LARGE HAIL, DAMAGING WIND GUSTS, AND TORNADOES.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 309 AM CDT THU APR 2 2026
WRAP AROUND PRECIPITATION SKIMS FAR NORTHERN IOWA ON SATURDAY,
HOWEVER WILL BE OF LITTLE IMPACT WITH TEMPERATURES WARM ENOUGH
FOR THIS TO FALL AS LIGHT RAIN. COOLER BEHIND THE COLD FRONT
WITH HIGHS ON SATURDAY IN THE 40S. BY SUNDAY TEMPERATURES WARM
INTO THE 50S WITH DRY CONDITIONS. COOL AND BENIGN CONDITIONS
THROUGH THE FIRST PART OF NEXT WEEK, BECOMING MORE ACTIVE LATER
IN THE WEEK.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1125 PM CDT WED APR 1 2026
IFR OR LOWER CONDITIONS WILL PREVAIL OVERNIGHT AS SHOWERS, LIGHT
FOG, AND VERY LOW CLOUDS BLANKET THE AREA. SHOWERS WILL DECREASE
IN COVERAGE/FREQUENCY AROUND MIDDAY THURSDAY AND WE WILL SEE
SOME GRADUAL RISING OF CEILINGS, MAINLY AT DSM AND OTM. A BRIEF
PERIOD OF THUNDERSTORMS MAY IMPACT DSM/ALO/OTM AROUND 18-23Z,
FOLLOWED QUICKLY BY A COOL FRONT WITH TEMPERATURES TURNING TO
ROUGHLY NORTHWEST BY THE END OF THE TAF PERIOD. LOW CLOUDS AND
FOG MAY REDEVELOP THURSDAY NIGHT, BUT CONFIDENCE IS LOW AND THIS
WILL BE ADDRESSED IN LATER TAF ISSUANCES.
HYDROLOGY
ISSUED AT 130 PM CDT WED APR 1 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...HAGENHOFF
LONG TERM...HAGENHOFF
AVIATION...LEE
HYDROLOGY...ZOGG
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