818  
FXUS63 KDMX 032335  
AFDDMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DES MOINES IA  
635 PM CDT WED JUN 3 2026  
 
...UPDATED FOR THE 00Z AVIATION DISCUSSION...  
   
KEY MESSAGES
 
 
- DRY CONDITIONS CONTINUE THROUGH TONIGHT; THEN STORMS ARRIVE  
FAR NORTHWEST AFTER MIDNIGHT.  
 
- MARGINAL RISK (LEVEL 1 OUT OF 5) OF SEVERE WEATHER THURSDAY  
AFTERNOON/EVENING.  
 
- RAIN/STORM CHANCES CONTINUE INTO FRIDAY EVENING WITH THE  
POSSIBILITY OF SEVERE WEATHER AND HEAVY RAIN. SLIGHT RISK PER  
SPC.  
 
- TEMPERATURES RETURN TO THE UPPER 80'S OVER THE WEEKEND.  
 

 
   
SHORT TERM /THROUGH FRIDAY NIGHT/
 
 
ISSUED AT 257 PM CDT WED JUN 3 2026  
 
DRY, WARM, AND BREEZY CONDITIONS ARE COMMON ACROSS CENTRAL IOWA  
TODAY, WITH AFTERNOON TEMPERATURES AS OF 2PM IN THE UPPER 70S  
TO LOW 80S AND SOUTH/SOUTHEASTERLY WINDS GUSTING TO 20-25 MPH,  
WHILE AREAS ON NORTHERN IOWA HAVE SEEN HIGHER GUSTS AT TIMES UP  
TO 30-35 MPH. THE SYNOPTIC SETUP RESPONSIBLE FOR THIS WEATHER  
FEATURES A LARGE AREA OF RIDGING AND ASSOCIATED SURFACE HIGH  
PRESSURE THAT IS CENTERED OVER THE OHIO VALLEY, WITH ITS  
INFLUENCE REMAINING ACROSS IOWA, WHILE FURTHER WEST, A TROUGH IS  
MOVING ACROSS SOUTHERN SASKATCHEWAN/MANITOBA. THE HIGH PRESSURE  
AREA WILL CONTINUE TO ALLOW FOR DRY CONDITIONS THROUGH THE REST  
OF TODAY, THOUGH WILL CONTINUE TO DEPART EASTWARD INTO THE  
EVENING/THURSDAY MORNING. WILL SEE A NOTICEABLE CHANGE AS  
MOISTURE RETURN AS IT INCREASES ACROSS WESTERN IOWA TONIGHT,  
WHICH WILL CONTINUE TO TRANSLATE FURTHER NORTH AND EAST OVER THE  
NEXT FEW DAYS AND GENERALLY BRING A MORE ACTIVE PATTERN ACROSS  
IOWA INTO THE WEEKEND.  
 
THE FIRST CHANCE FOR SHOWERS AND STORMS IN THE SHORT TERM WILL  
COME FROM A BOUNDARY IN RELATION TO THE CANADIAN TROUGH  
MENTIONED ABOVE, WHICH IS SLATED TO ARRIVE INTO NORTHWEST IOWA  
AFTER MIDNIGHT TONIGHT AND DROP SOUTHEAST INTO THE STATE THROUGH  
THE MORNING. SHOWERS AND STORMS ARE EXPECTED TO ARRIVE IN  
RELATION TO THIS BOUNDARY, BUT WILL BE ON A WEAKENING TREND AS  
THEY TRACK OUT OF THE DAKOTAS/NEBRASKA. THE PARAMETER SPACE OVER  
IOWA FEATURES INSTABILITY VALUES LESS THAN 500 J/KG AND SHEAR  
VALUES UNDER 25 KNOTS, WHICH SHOULD KEEP ANY STORMS THAT LINGER  
INTO IOWA BELOW SEVERE LIMITS. WITH DRY AIR STILL OVER MUCH OF  
CENTRAL AND EASTERN IOWA, ANY SHOWERS AND STORMS WILL GENERALLY  
STRUGGLE TO MAINTAIN THEMSELVES AS WELL, BUT COULD HOLD THE  
POTENTIAL FOR GUSTY NON-SEVERE WINDS AS THEY COLLAPSE.  
 
BY LATE THURSDAY MORNING AND ESPECIALLY THE AFTERNOON,  
DESTABILIZATION BECOMES WIDESPREAD OVERHEAD, WITH INSTABILITY  
VALUES AROUND 1000-2000 J/KG, PAIRED WITH SHEAR VALUES AROUND  
25-30 KNOTS AS TEMPERATURES RISE THROUGH THE 80S. THESE  
CONDITIONS, PAIRED WITH THE ARRIVAL OF A SHORTWAVE MOVING  
NORTHEAST ACROSS IOWA AND FURTHER FORCING FOR LIFT INTO THE  
EVENING BY THE STRENGTHENING LOW LEVEL JET WILL ALLOW FOR  
SCATTERED SHOWERS AND STORM CHANCES TO RETURN ACROSS WESTERN AND  
SOUTHERN IOWA, INCREASING IN COVERAGE THROUGH THE EVENING AS  
THIS ACTIVITY TRACKS NORTHEASTWARD. THE PRIMARY HAZARDS OF  
CONCERN WILL BE HAIL AND GUSTY WINDS, THOUGH HEAVY RAIN  
CONTINUES TO BE INCREASINGLY LIKELY AS WELL WHERE STORMS PASS  
THROUGH, GIVEN VERY FAVORABLE PWATS OF 1.6-1.7 INCHES MOVING  
OVER MUCH OF THE AREA. THOUGH SOILS OVER MUCH OF THE STATE ARE  
DRY, QUICK ACCUMULATIONS OF 1-2+ INCHES COULD EASILY OCCUR WHERE  
STRONGER STORMS SETUP. A SLIGHT RISK PER WPC HAS BEEN  
INTRODUCED OVER PORTIONS OF SOUTHWEST/WESTERN IOWA TO ACCOUNT  
FOR THIS POTENTIAL.  
 
HIGHEST DEWPOINTS IN THE MID TO UPPER 60S ARRIVE OVER MUCH OF  
IOWA INTO FRIDAY AS MOISTURE ADVECTION FROM THE GULF BECOMES  
MAXIMIZED. SHOWERS AND STORM COVERAGE LOOK TO REMAIN THROUGH THE  
MAJORITY OF FRIDAY MORNING AS THE LOW LEVEL JET SLOWLY FADES,  
ESPECIALLY OVER SOUTHERN IOWA. WHILE THE SEVERE RISK IS LESSENED  
DURING THE MORNING HOURS GIVEN MORE LIMITED INSTABILITY  
OVERHEAD, STORMS ARE STILL EXPECTED TO OCCUR. DRYING CONDITIONS  
RETURN BRIEFLY, BUT WILL SEE STORM CHANCES RETURN ONCE AGAIN  
FRIDAY AFTERNOON AND ESPECIALLY THE EVENING AS ANOTHER MID-LEVEL  
SHORTWAVE IS EXPECTED TO PASS ACROSS THE UPPER MIDWEST, WITH AN  
ASSOCIATED DEFINED COLD FRONT ARRIVING INTO IOWA. THIS WEST TO  
EAST BOUNDARY WILL BE THE FEATURE RESPONSIBLE FOR YET ANOTHER  
PERIOD OF SHOWERS AND THUNDERSTORMS, WHICH WILL GRADUALLY TRACK  
SOUTH/SOUTHEAST WITH THE PASSING BOUNDARY THROUGH FRIDAY NIGHT.  
HIGHER INSTABILITY VALUES AHEAD OF THIS FEATURE AROUND 2000+  
J/KG, SHEAR VALUES UP TO 30-35 KNOTS AND STEEP LAPSE RATES OF  
7-8 C/KM OVERHEAD WILL LEAD TO THE HIGHEST POTENTIAL FOR STRONG  
TO SEVERE STORMS. A SLIGHT RISK FOR SEVERE WEATHER REMAINS  
ACROSS MUCH OF THE FORECAST AREA PER SPC GIVEN THIS PARAMETER  
SPACE, WHERE ALL HAZARDS ARE POSSIBLE. HEAVY RAIN GIVEN SIMILAR  
PWAT VALUES AND SLOWER STORM MOVEMENT WILL INTRODUCE ADDITIONAL  
CONCERNS FOR 1+ INCH AMOUNTS WHERE STRONGER AND REPEATED STORMS  
MOVE THROUGH.  
 

 
   
LONG TERM /SATURDAY THROUGH WEDNESDAY/
 
 
ISSUED AT 257 PM CDT WED JUN 3 2026  
 
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO  
SATURDAY MORNING, MAINLY OVER SOUTHERN IOWA IN RELATION TO WHERE  
THE FRONTAL BOUNDARY IS PROGGED TO GENERALLY STALL FOR THE DAY.  
WHILE MOST AREAS LOOK TO BE DRY FOR MUCH OF THE DAY, ADDITIONAL  
SHOWERS AND STORMS LOOK TO REDEVELOP OVER PARTS OF SOUTHERN  
IOWA IN RELATION TO THE LINGERING AFOREMENTIONED FRONT BY THE  
EVENING. CONFIDENCE HOWEVER ON EXACT PLACEMENT IS ON THE LOW END  
AT THIS TIME, AS MODELS SUCH AS THE GFS PUSH THIS BOUNDARY NEAR  
THE IA/MO BORDER INTO NORTHERN MISSOURI BY SATURDAY EVENING.  
CERTAINLY SOME PLACEMENT DIFFERENCES TO KEEP AN EYE ON OVER THE  
COMING DAYS. THE PATTERN SUNDAY AND BEYOND LOOKS TO REMAIN ON  
THE MORE ACTIVE SIDE AS ADDITIONAL WAVE PASS THROUGH THE AREA,  
ALONG WITH SLIGHTLY WARMER TEMPERATURES OVERHEAD. MORE SPECIFIC  
DETAILS HOWEVER ON TIMING AND LOCATION OF SHOWERS AND STORMS  
WILL BE BETTER KNOWN IN THE COMING DAYS AS MODELS BETTER CAPTURE  
THESE FEATURES.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
 
 
ISSUED AT 635 PM CDT WED JUN 3 2026  
 
PREVAILING VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD,  
HOWEVER, THERE WILL BE CHANCES FOR SHRA/TSRA AT TIMES.  
INITIALLY, WEAKENING CONVECTION IS ANTICIPATED LATE TONIGHT INTO  
EARLY THURSDAY MORNING IN THE NORTHWESTERN HALF OF IOWA, WHERE  
FOD AND MCW MAY BE AFFECTED BRIEFLY AROUND SUNRISE. EVEN IN THIS  
FIRST ROUND OF SHOWERS/STORMS, ANY RESTRICTIONS BELOW VFR WOULD  
BE SPOTTY AND BRIEF. THURSDAY AFTERNOON AND EVENING, TOWARD THE  
END OF THE 00Z TAF PERIOD, MORE WIDESPREAD STORMS ARE  
ANTICIPATED WITH A HIGHER PROBABILITY OF MVFR OR LOWER  
VISIBILITIES, BUT GIVEN LOW CONFIDENCE IN TIMING OF LOCATION,  
COVERAGE, AND TIMING, HAVE LIMITED MENTION TO PROB30 GROUPS FOR  
NOW.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 631 PM CDT WED JUN 3 2026  
 
FLASH FLOOD CONCERNS EXIST OVER AT LEAST THE NEXT FEW DAYS,  
PRIMARILY BETWEEN THURSDAY AFTERNOON AND FRIDAY NIGHT. WPC  
INTRODUCED A SLIGHT RISK FOR THE WESTERN CWA IN THEIR DAY 2  
EXCESSIVE RAINFALL OUTLOOK UPDATE THIS AFTERNOON. (SEE THE WPC  
EXCESSIVE RAINFALL DISCUSSION FOR DETAILS.) FLASH FLOODING MAY  
OCCUR FROM HEAVY RAINFALL AMOUNTS OR THE SHEER RAINFALL  
INTENSITIES SINCE THE ACTIVITY HAS THE POTENTIAL TO BE EFFICIENT  
RAINFALL PRODUCERS. THE GREATEST RISK OF ANY FLASH FLOODING  
WOULD BE IN CITIES AND TOWNS.  
 
THE RISK OF RIVER FLOODING OVER THE NEXT 10 DAYS IS MINIMAL  
(GENERALLY LESS THAN 10-20%), HOWEVER MINOR TO MODERATE WITHIN-  
BANK RISES ARE POSSIBLE IN BASINS THAT RECEIVE HEAVIER RAINFALL.  
 

 
   
DMX WATCHES/WARNINGS/ADVISORIES
 
NONE.  
 

 
 

 
 
SHORT TERM...BURY  
LONG TERM...BURY  
AVIATION...LEE  
HYDROLOGY...ZOGG  
 
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