602
FXUS63 KDMX 301722
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1222 PM CDT WED APR 30 2025
...UPDATED FOR THE 18Z AVIATION DISCUSSION...
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS EXPAND ACROSS THE AREA TODAY,
BECOMING WIDESPREAD BY THIS EVENING.
- ADDITIONAL SHOWERS AND THUNDERSTORMS ON THURSDAY AND FRIDAY.
- WARMER AND DRY FOR THE WEEKEND.
DISCUSSION
ISSUED AT 259 AM CDT WED APR 30 2025
THE SOUTHERN STREAM TROUGH HAS PUSHED INTO THE CENTRAL US WITH CLOUD
COVER SPREADING INTO IOWA THROUGH THE EARLY MORNING HOURS.
CONDITIONS AHEAD OF THE PRECIPITATION ARE PRETTY DRY WITH DEWPOINT
DEPRESSIONS OF 10-15 DEG F. MODEL SOUNDINGS ACROSS THE AREA ARE SLOW
TO SATURATE INTO THE LOW LEVELS THROUGH MIDDAY AND EARLY
PRECIPITATION ACROSS SOUTHERN TO CENTRAL IOWA IS EXPECTED TO BE
FAIRLY SPOTTY. BY THIS AFTERNOON PROFILES SATURATE AND CAMS
DEVELOP MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE AREA. THIS WILL LAST THROUGH THE OVERNIGHT BEFORE LIFTING
OFF TO THE EAST ON THURSDAY MORNING. THE NORTHERN STREAM
SHORTWAVE DOESN'T QUITE PHASE AND ENDS UP PASSING ACROSS THE
AREA LATER THURSDAY AFTERNOON, PROVIDING ANOTHER WINDOW FOR
SHOWERS AND THUNDERSTORMS. A FINAL LOBE OF VORTICITY ROTATES
ACROSS THE AREA ON FRIDAY WITH ANOTHER WINDOW FOR SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. THIS FINAL EMBEDDED SHORTWAVE IS
FINALLY ENOUGH TO SHIFT THE PARENT TROUGH EAST OF THE AREA IN
TIME FOR THE WEEKEND. THE ENTIRE PERIOD HAS MEAGER INSTABILITY
WITH UNDER 500 J/KG MLCAPE AND LITTLE IN THE WAY OF A WELL
DEFINED FORCING MECHANISM TO FOCUS CONVECTION. AS SUCH, SEVERE
CHANCES ARE QUITE LOW THOUGH RUMBLES OF THUNDER ARE CERTAINLY
ANTICIPATED. A WIDESPREAD 0.25" OF QPF IS FORECAST WITH HREF
LPMM PAINTING MUCH OF THE AREA AS SUCH WITH POCKETS OF LOCALLY
HIGHER AMOUNTS.
THE WESTERN US THERMAL RIDGE WILL BUILD ACROSS THE AREA FOR THE
WEEKEND, KEEPING THE AREA DRY AND SENDING TEMPERATURES BACK INTO THE
70S ACROSS IOWA. A RATHER ROBUST SYSTEM WILL DEVELOP OVER THE
WESTERN US DURING THIS TIME AND SHOULD MOVE INTO THE CENTRAL US
SOMETIME EARLY NEXT WEEK. THERE IS SIGNIFICANT SPREAD IN MODEL
GUIDANCE AT THIS RANGE, ESPECIALLY IN REGARD TO TIMING AND THIS
WILL NEED TO BE FINE TUNED LATER. AS IS OFTEN THE CASE WITH
UPPER LEVEL CUT OFF LOWS, A DELAY IN ARRIVAL NEXT WEEK IS
POSSIBLE.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1222 PM CDT WED APR 30 2025
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON WITH A FEW BRIEF
LIGHT SHOWERS EXPECTED TO HAVE LITTLE TO NO IMPACT. BY TONIGHT
LOWER CEILINGS WILL WORK IN, FIRST MVFR AND THEN LOWERING TO IFR
AT MOST TERMINALS ESPECIALLY AFTER MIDNIGHT. MORE SHOWERS AND
ISOLATED THUNDERSTORMS ARE ALSO FORECAST AND HAVE INCLUDED
PROB30 GROUPS AROUND THE RELATIVELY LIKELIER TIME FRAMES,
HOWEVER, CONFIDENCE IN TIMING AND COVERAGE IS LOW AND UPDATES
AND AMENDMENTS ARE LIKELY OVERNIGHT.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...HAGENHOFF
AVIATION...LEE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page