193  
FXUS63 KDMX 291949  
AFDDMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DES MOINES IA  
249 PM CDT TUE APR 29 2025  
   
KEY MESSAGES  
 
- LOWS WILL DROP INTO THE MID 30S NORTH TONIGHT.  
 
- RAIN AND A FEW THUNDERSTORMS POSSIBLE WEDNESDAY. NO SEVERE  
WEATHER EXPECTED, AT THIS TIME.  
 
- LIGHT RAIN AND SOME RUMBLES OF THUNDER THROUGH FRIDAY, WARMING  
BACK UP OVER THE WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 246 PM CDT TUE APR 29 2025  
 
HEIGHT RISES AND A SURFACE HIGH KEPT WEATHER FAIR TODAY. WINDS  
WILL CONTINUE TO SLOW THROUGH THE AFTERNOON AS THE HIGH'S  
INFLUENCE INCREASES. HIGHS WILL BE IN THE LOW TO MID 60S WITH  
SOME PLACES IN THE NORTH REMAINING IN THE UPPER 50S. MAIN CHANGE  
THIS FORECAST WAS LEANING ON THE LOWER END OF GUIDANCE  
SOLUTIONS FOR TEMPERATURES ACROSS THE NORTH TONIGHT. A MIXTURE  
OF SUBSIDENCE, CALM WINDS AND MOSTLY CLEAR SKIES WILL ALREADY  
ALLOW LOWS TO UNDERPERFORM, BUT ADD TO IT THE DRY LOW-LEVELS  
(SURFACE DEW POINT DEPRESSIONS ARE ON AVERAGE AROUND 15  
DEGREES) FROM THE HIGH PRESSURE AND TEMPERATURES WILL BE ABLE TO  
SINK INTO THE MID 30S. HAVE LOWERED TEMPERATURES ONLY AS FAR  
SOUTH AS THE HIGHWAY 20 CORRIDOR AS MIDLEVEL CLOUDS WILL BEGIN  
THEIR SNOW NORTHWARD PROGRESSION AFTER MIDNIGHT, KEEPING  
SOUTHERN IOWA WARMER, IN COMPARISON.  
 
SOME NOTABLE CHANGES IN THE SYNOPTIC PATTERN FOR THE REST OF THE  
WORK WEEK. THE CLOSED LOW IN THE SW US WILL NOW ARRIVE IN THE REGION  
BEFORE THE NORTHERN STREAM TROUGH DOES, DEEPENING AS IT DOES. THIS  
FEATURE WILL LOCK IN MOST OF THE LOW-LEVEL MOISTURE FETCH AND  
REDIRECT IT INTO THE OHIO RIVER VALLEY. THE MORE SOUTHERLY TREND OF  
THE SYSTEM HAS TAKEN THE INSTABILITY GRADIENT WITH IT, WITH MUCAPE  
VALUES REMAINING UNDER 500 J/KG IN THE FAR SOUTH. THERE WILL BE SOME  
POSSIBLE THUNDERSTORMS WITH THIS MUCH INSTABILITY, BUT ACTIVITY  
WON'T BE SEVERE. RAINFALL AMOUNTS WILL BE LARGELY UNDER AN INCH, BUT  
CONVECTION IN THE FAR SOUTHEAST COULD LEAD TO LOCALLY HIGHER  
AMOUNTS. HAVE LOWERED TEMPERATURES TO REFLECT THE CLOUDY, WET  
CONDITIONS. THE NORTHERN STREAM SYSTEM DIVES IN FOR THURSDAY,  
BRINGING WITH IT AN REINFORCING SHOT OF PACIFIC MOISTURE TO KEEP  
PRECIPITATION GOING. FINALLY, ANOTHER SHORTWAVE PIVOTS FROM THE  
NORTHWEST FOR ADDITIONAL LIGHT RAIN CHANCES ON FRIDAY.  
 
AN OMEGA BLOCK PATTERN TAKES SHAPE OVER THE WEEKEND WITH IOWA BEING  
IN PROXIMITY OF THE INFLUENCE OF THE RIDGE. TEMPERATURES WILL  
RESPOND BY RETURNING INTO THE 70S. ACTIVE SPRING WEATHER WON'T BE  
FAR AWAY AS THE INFLUENCE FROM THE CLOSED LOW IN THE SW US WILL  
CHURN IN PVA AND GULF MOISTURE, HENCE THE RAIN CHANCES IN THE WEST  
TOWARDS THE END OF THE PERIOD  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/  
 
ISSUED AT 1218 PM CDT TUE APR 29 2025  
 
HAVE ADDED IN SHRA MENTIONS FOR KDSM AND KOTM AFTER 12Z TO  
REFLECT RAIN ARRIVING FROM THE SOUTH. CANNOT RULE OUT  
THUNDERSTORMS FOR KOTM, BUT THESE WOULD BE NON-SEVERE. CIGS  
SHOULD REMAIN VFR UNTIL RIGHT AT 18Z. WINDS WILL BECOME  
SOUTHERLY THROUGH THE NIGHT.  
 
 
   
DMX WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION...JIMENEZ  
AVIATION...JIMENEZ  
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