939  
FXUS63 KDMX 210501  
AFDDMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DES MOINES IA  
1201 AM CDT WED MAY 21 2025  
 
...UPDATED FOR THE 06Z AVIATION DISCUSSION...  
   
KEY MESSAGES
 
 
- GENERALLY COOL OVER THE NEXT WEEK WITH VERY LOW CHANCES FOR  
SEVERE WEATHER THROUGH MOST OF THE PERIOD.  
 
- VERY COOL NORTH WITH HIGHS IN THE 40S AND A FEW SHOWERS ON  
WEDNESDAY.  
 
- NEXT MAIN CHANCE FOR PRECIPITATION ARRIVES THIS WEEKEND.  
 

 
   
DISCUSSION
 
 
ISSUED AT 236 PM CDT TUE MAY 20 2025  
 
LARGE AREA OF SURFACE LOW PRESSURE IS CENTERED OVER IOWA WITH A  
PRONOUNCED INVERTED TROUGH EXTENDING NORTHWEST THROUGH THE DAKOTAS. A  
SECONDARY VORTICITY LOBE IS ROTATING AROUND THE SOUTHERN PERIPHERY  
OF THE UPPER LEVEL LOW. THAT SHORT WAVE IS MOVING ACROSS KANSAS AND  
MISSOURI EARLY THIS AFTERNOON AND THIS SYSTEM IS HELPING FIRE A  
SHOWERS AND STORMS OVER PARTS OF SOUTHEAST IOWA/NORTHEAST MISSOURI  
AND INTO ILLINOIS. OTHER SHOWERS ARE OVER CENTRAL AND NORTH CENTRAL  
IOWA. AS THIS SURFACE LOW MOVES EAST INTO TONIGHT AND WEDNESDAY, THE  
INVERTED TROUGH WILL BE DRAGGED EAST, WHICH IN ITS CURRENTLY  
ORIENTATION, WILL ALSO RESULT IN IT MOVING NORTH AND EAST ACROSS THE  
STATE.  
 
THE NEXT SEVERAL DAYS WEATHER WILL HAVE THE UPPER LOW TO THE NORTH  
TO SHEAR OUT AND EVENTUALLY HAVE THE HUDSON BAY UPPER LOW TAKE OVER  
AND SETTLE SOUTH INTO THE GREAT LAKES REGION BY THURSDAY. FOR  
WEDNESDAY, WITH THE SURFACE INVERTED TROUGH NEARBY, IOWA WILL HAVE  
MOSTLY CLOUDY AND VERY COOL TEMPERATURES OVER NORTHERN IOWA AND MORE  
SUN AND WARMER ACROSS THE SOUTH. BY THURSDAY, THE UPPER LOW  
EVOLUTION WILL LEAD TO COOL CYCLONIC FLOW OVER IOWA. A FEW PERIODS  
OF LIGHT RAIN IS POSSIBLE OVER NORTHERN IOWA THROUGH WEDNESDAY NIGHT  
AND A FEW SPRINKLES COULD OCCUR INTO THURSDAY. ANOTHER UPPER LEVEL  
PATTERN TRANSITION WILL OCCUR LATE IN THE WEEK WITH A MORE MODIFIED  
ZONAL FLOW OCCURRING THOUGH OVERALL IOWA WILL BE ON THE COOLER SIDE  
OF THIS PATTERN. MOISTURE OVERRUNNING THIS COOLER AIR IS EXPECTED  
THIS WEEKEND AND THAT MAY BRING THE NEXT CHANCE FOR PRECIPITATION TO  
IOWA WITH THE GREATEST CHANCES OVER SOUTHERN IOWA. THESE  
PRECIPITATION CHANCES MAY LINGER INTO NEXT MONDAY. TEMPERATURES FOR  
LATE WEEK AND INTO EARLY NEXT WEEK WILL BE SEASONABLY COOL WITH  
HIGHS IN THE 60S TO LOW 70S. MORE SIGNIFICANT WARMING SHOULD ARRIVE  
BY MID NEXT WEEK WITH AN UPPER LEVEL RIDGE MOVING INTO THE  
REGION.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
 
 
ISSUED AT 1159 PM CDT TUE MAY 20 2025  
 
IFR/LIFR CIGS WITH VSBY RESTRICTIONS FROM DRIZZLE TO AFFECT KMCW  
AND KALO FOR AT LEAST THE NEXT 6 HOURS, EASING IN INTENSITY  
THROUGH THE MORNING AND IMPROVING TO MVFR CIGS. VFR WILL RETURN  
AFTER 18Z. NORTHWEST WINDS WILL HAVE GUSTS TO AROUND 20KTS UNTIL  
00Z.  
 

 
   
DMX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
DISCUSSION...DONAVON  
AVIATION...JIMENEZ  
 
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