170
FXUS63 KDMX 232331
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
631 PM CDT THU APR 23 2026
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- A LINE OF SEVERE STORMS WILL MOVE ACROSS IOWA LATE AFTERNOON
AND EVENING. A FEW NON-SEVERE SHOWERS AND STORMS POSSIBLE
AHEAD OF THE MAIN LINE. THE LINE OF STORMS WILL HAVE WIND AS
THE PRIMARY HAZARD, THOUGH TORNADOES AND HAIL ARE POSSIBLE.
- COOLER FRIDAY THROUGH THE WEEKEND. MULTIPLE ROUNDS OF SHOWERS
AND THUNDERSTORMS POSSIBLE THIS WEEKEND AND EARLY NEXT WEEK.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 207 PM CDT THU APR 23 2026
A FEW SPOTTY SHOWERS HAVE DEVELOPED IN THE MOIST PLUME EXTENDING
INTO IOWA, THOUGH HAVE BEEN FAIRLY SORT LIVED WITH LITTLE MECHANISM
TO SUSTAIN DEVELOPMENT. MEANWHILE, CONVECTION HAS FIRED ALONG AND
JUST AHEAD OF THE COLD FRONT PUSHING ACROSS NEBRASKA AND INTO
WESTERN IOWA. THIS WILL PUSH ACROSS IOWA THIS EVENING, REACHING THE
I-35 CORRIDOR AROUND 7-9PM AND PUSHING EAST AFTER MIDNIGHT. THERE
WAS SOME CONCERN THAT PREFRONTAL CONVECTION WOULD PREVENT MORE
ROBUST DEVELOPMENT WITH THE MAIN LINE OF STORMS. WHILE THIS HAS NOT
YET MATERIALIZED, THE WIDESPREAD STRATUS HAS PUT A BIT OF A DAMPER
ON INSTABILITY. THERE IS LITTLE DCAPE OUT THERE AND WITH MOIST
SOUNDINGS THROUGH THE LOW LEVELS, THAT MAY PREVENT BETTER COLD POOL
DEVELOPMENT EXCEPT IN NORTHERN IOWA WHERE THERE IS DRIER AIR IN
PLACE. THIS WOULD IMPACT WIND POTENTIAL WITH THE LINE AS IT BLOWS
THROUGH. A POOL OF 2500+ J/KG SBCAPE IS IN PLACE ACROSS WESTERN TO
CENTRAL IOWA WITH THE CRESTON SOUNDING SHOWING 1900+ ECAPE AS SOME
MAY NOT BE REALIZED DUE TO ENTRAINMENT. SHEAR IS LARGELY PARALLEL TO
THE BOUNDARY. THIS COULD LIMIT SOME OF THE TORNADO THREAT UNLESS A
BOWING SECTION CAN TAKE BETTER ADVANTAGE OF LINE NORMAL SHEAR.
TORNADO THREAT WOULD BE HIGHEST WITH INITIAL CONVECTION THAT IS
MORE LIKELY TO BE SURFACE BASED, ALONG WITH THE LOW LCLS AROUND
500M. HAIL CONCERNS WILL ALSO BE GREATEST WITH INITIAL DISCRETE
CONVECTION WHEN LAPSE RATES ARE STEEPER AROUND 7-8 C/KM. AS THE
LINE GROWS UPSCALE WITH COLUMN MOISTENING AND PUSHES EAST LATER
THIS EVENING THREATS WILL START TO DIMINISH.
LONG TERM /FRIDAY THROUGH THURSDAY/
ISSUED AT 207 PM CDT THU APR 23 2026
RELATIVELY COOLER CONDITIONS SETTLE IN FRIDAY THROUGH THE WEEKEND
AND MUCH OF THE UPCOMING WEEK. WHILE COOLER THAT RECENT DAYS,
AVERAGE HIGHS THIS TIE OF YEAR ARE IN THE MID 60S, SO TEMPERATURES
WILL BE CLOSER TO WHAT IS "TYPICAL" FOR THIS TIME OF YEAR. THE
PATTERN REMAINS ACTIVE THIS WEEKEND AND NEXT WEEK AS SEVERAL
EMBEDDED SHORTWAVE EJECT EAST FROM A LONGWAVE TROUGH PARKED ACROSS
ALBERTA AND SASKATCHEWAN. THE FIRST IS RATHER WEAK AND MAY SKIM THE
AREA ON SATURDAY. THEN A MORE ROBUST WAVE LIFTS OUT OF MISSOURI
TOWARDS THE AREA ON SUNDAY. THIS WILL INTERACT WITH THE MAIN
LONGWAVE TROUGH FINALLY DIGGING EAST SUNDAY INTO MONDAY. AS THIS
INTERACTS WITH THE SYSTEM LIFTING OUT OF MISSOURI THUNDERSTORMS
ARE EXPECTED INTO IOWA. PLACEMENT OF THE WARM SECTOR WILL
IMPACT SEVERE THREATS INTO IOWA AND WILL BE BETTER DETERMINED IN
THE NEXT FEW DAYS.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 623 PM CDT THU APR 23 2026
MAIN AVIATION CONCERN IN THE SHORT TERM WILL FOCUS ON
PROGRESSION OF LINE OF STRONG TO SEVERE THUNDERSTORMS THROUGH
CENTRAL IOWA.
THUNDERSTORMS WITH HEAVY RAIN WILL IMPACT ALL TERMINALS WITH
LOW-END MVFR TO IFR CONDITIONS LIKELY. CANNOT RULE OUT BRIEF
LIFR, BUT WILL MONITOR TRENDS FOR THIS THREAT. HAVE MAINTAINED
GREATEST IMPACTS AT DSM/FOD/MCW AS INTENSITY SHOULD BE HIGHEST
AT THESE SITES BEFORE SLIGHT DECREASES EAST OF I-35. CAN'T RULE
OUT BRIEF 40+ KNOT GUSTS AS LEADING EDGE OF STORMS MOVE IN BUT
WILL PINPOINT TIMING BETTER BEFORE INSERTING MENTION AT DSM WITH
LATER AMENDMENTS.
TONIGHT, SKIES SHOULD CLEAR QUICKLY ONCE TSRA DEPART. WILL
MAINTAIN SOME LOWER COVERAGE OF LOW/MID CLOUDS FOR THE EARLY
MORNING FRIDAY BEFORE SUNNY TO MOSTLY SUNNY SKIES PREVAIL
ACROSS THE AREA FOR THE BULK OF THE DAYTIME FRIDAY. WINDS MAY
INCREASE EARLY IN THE MORNING, POTENTIALLY AROUND 20-25 KNOTS
OUR OF THE NORTHWEST, WITH A GRADUAL DECREASE TOWARDS THE END
OF THE PERIOD.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...HAGENHOFF
LONG TERM...HAGENHOFF
AVIATION...NMJ/WFO LBF
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