755
FXUS63 KDMX 011953
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
253 PM CDT MON JUN 1 2026
KEY MESSAGES
- ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE (20 TO 30%) THIS
AFTERNOON OVER WESTERN IOWA. A STRONGER STORM COULD PRODUCE
GUSTY WINDS, SMALL HAIL AND LOCALLY HEAVY RAINFALL.
- DRIER CONDITIONS DEVELOP TUESDAY THROUGH THE DAY WEDNESDAY.
HIGHS IN THE LOW 80S WITH BREEZY WINDS OVER WESTERN AND
NORTHWESTERN IOWA.
- PATTERN TURNS MORE ACTIVE THROUGH THE SECOND HALF OF THE WEAK,
WITH MULTIPLE ROUNDS OF RAIN AND THUNDERSTORMS POSSIBLE INTO
THE WEEKEND.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 250 PM CDT MON JUN 1 2026
SUNNY SKIES AND DRY CONDITIONS HAVE GRACED MOST OF THE STATE TODAY,
ALTHOUGH ONE ROGUE STORM IN NORTHERN IOWA DID SPOIL THE NICE DAY FOR
THOSE IN EMMET AND PALO ALTO COUNTIES, PRODUCING GUSTY WINDS AND
OVER AN INCH OF RAIN AS IT PASSED THROUGH. FORTUNATELY, THIS STORM
HAS SINCE DISSIPATED, LEAVING MOSTLY CLEAR SKIES AND PLEASANT
CONDITIONS OVER ALL OF CENTRAL IOWA.
SCATTERED CUMULUS HAS STARTED TO DEVELOP AS THE BOUNDARY LAYER MIXES
OUT AND ATMOSPHERE BEGINS TO DESTABILIZE TODAY. THE VERTICAL
PROFILES OVER IOWA ARE FAIRLY DRY, BUT A SUBTLE SHORTWAVE PASSING
THROUGH NEBRASKA WILL TRY TO PULL BETTER MID-LEVEL MOISTURE INTO
WESTERN IOWA THIS AFTERNOON. THIS SAME AREA WILL BOAST 2000 TO 3000
J/KG OF MLCAPE AND MODEST MID-LEVEL LAPSE RATES. THE OVERALL FORCING
WITH THIS WAVE IS WEAK, BUT HIGHER RESOLUTION GUIDANCE DOES INDICATE
SOME SUBTLE CONVERGENCE IN THE LOW LEVELS. THESE FACTORS MAY BE JUST
ENOUGH FOR A FEW ISOLATED SHOWERS OR STORMS TO DEVELOP AS WE REACH
PEAK HEATING THIS AFTERNOON, MAINLY OVER WESTERN IOWA. IF STORMS DO
MANAGE TO TAKE OFF, THE RESPECTABLE AMOUNT OF INSTABILITY IN PLACE
COULD LEAD TO SOME STRONGER UPDRAFTS. THE STEEP LOW LEVEL LAPSE
RATES AND DOWNDRAFT CAPE OF 1000+ J/KG WILL ALSO BE CONDUCIVE FOR
GUSTY WINDS AS STORMS PRECIPITATE INTO THE DRY LAYER BELOW. HOWEVER,
THE 0 TO 6 KM WIND SHEAR WILL BE MARGINAL (20 TO 30 KTS) AND
UPDRAFTS MAY STRUGGLE TO ORGANIZE AND MAINTAIN THEMSELVES.
THEREFORE, PROLONGED SEVERE STORMS ARE NOT ANTICIPATED, BUT A FEW
STRONGER STORMS COULD STILL PRODUCE STRONG WINDS OR SMALL HAIL.
LIKEWISE, SOME VERY LOCALIZED HEAVY RAINFALL COULD OCCUR WITH THESE
STORMS, AS STORM MOTIONS WILL BE EXTREMELY SLOW, WHICH COULD LEAD TO
A QUICK INCH OR SO OF RAIN.
THE AFTERNOON ACTIVITY SHOULD GENERALLY DIMINISH INTO THE EVENING AS
THE SHORTWAVE WEAKENS AND A GREAT LAKES HIGH BEGINS TO PUSH INTO AND
ESTABLISH ITSELF OVER IOWA. MODEL GUIDANCE DOES STILL TRY TO PRODUCE
AN MCS OVER THE PLAINS TO OUR WEST OVERNIGHT, BUT THIS ACTIVITY GETS
STOPPED IN IT'S TRACKS ALONG THE IOWA/NEBRASKA BORDER WHERE IT MEETS
THE DRY AIR MASS ADVECTING IN FROM THE EAST. THIS SURFACE HIGH WILL
LINGER THROUGH TUESDAY AND WEDNESDAY, KEEPING THE LOW AND MID LEVEL
MOISTURE STREAMS TO THE WEST OF OUR FORECAST AREA AND CENTRAL IOWA
DRY THROUGH THE MIDDLE OF THE WEEK. CONDITIONS OVER THE STATE WILL
BE FAIRLY PLEASANT THROUGH THIS PERIOD, WITH HIGHS IN THE LOW 80S
AND PERIODS OF SUNSHINE. WITH WESTERN IOWA BEING MORE ON THE EDGE OF
THE SURFACE HIGH, TIGHTER PRESSURE GRADIENTS AND PROXIMITY TO THE
BETTER MOISTURE STREAM WILL LEAD TO BREEZIER CONDITIONS AND MORE
CLOUD COVER THAN AREAS FARTHER EAST, BUT OVERALL SHOULD STILL REMAIN
DRY THROUGH THE DAY WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 250 PM CDT MON JUN 1 2026
WEDNESDAY NIGHT AND THROUGH THE SECOND HALF OF THE WEEK WILL SEE A
SLIGHT CHANGE IN THE PATTERN, AS THE EASTERN US LONG-WAVE TROUGH
DEPARTS EASTWARD AND THE SURFACE HIGH FOLLOWS ALONG WITH IT. RETURN
FLOW ON THE BACKSIDE OF THE DEPARTING HIGH WILL ADVECT WARM MOIST
AIR UP INTO THE STATE, MEETING WITH ANOTHER SHORTWAVE TROUGH ALONG
THE US/CANADA BORDER WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BRING
THE RETURN OF SHOWER AND THUNDERSTORM CHANCES TO IOWA, MAINLY OVER
NORTHWEST INTO NORTHERN IOWA, ALTHOUGH RAIN COULD DEVELOP THROUGHOUT
THE AREA AS THETA-E ADVECTION INCREASES AHEAD OF THE WAVE. THIS
WEDNESDAY NIGHT INTO THURSDAY RAIN WILL KICK OFF A MORE ACTIVE
PATTERN THROUGH THE END OF THE WEEK, AS WE TRANSITION TO MORE OF A
ZONAL FLOW PATTERN WITH MULTIPLE SHORTWAVE PASSAGES INTO THE
WEEKEND. INSTABILITY WILL ALSO BE INCREASING THROUGH THE END OF THE
WEEK, AS THE WARMER AND HIGHER DEWPOINT AIR WORKS UP INTO THE STATE.
IT'S A BIT TOO EARLY TO DIG TOO FAR INTO THE SEVERE WEATHER
POTENTIAL, BUT FRIDAY LOOKS LIKE IT HAS THE GREATEST POTENTIAL FOR A
FEW STRONG STORMS, ALBEIT LIMITED BY LOW WIND SHEAR VALUES. MACHINE
LEARNING PROBABILITIES ARE KEYING ON FRIDAY AS WELL, PUTTING A 5 TO
15% PROBABILITY FOR SEVERE STORMS (EQUIVALENT TO A MARGINAL RISK
FROM SPC) ON FRIDAY. OF SIMILAR CONCERN WILL BE THE POTENTIAL FOR
MULTIPLE DAYS OF RAINFALL WEDNESDAY NIGHT THROUGH SATURDAY, SOME OF
WHICH COULD BE RATHER EFFICIENT AS THE BETTER MOISTURE STREAM AND
PWATS PIVOT WESTWARD INTO IOWA. THIS COULD BE SOME MUCH NEEDED
RAINFALL, PROVIDED IT DOESN'T ALL FALL IN ONE SPOT. POTENTIAL SEVERE
WEATHER AND HYDRO CONCERNS WILL CONTINUE TO BE EVALUATED IN THE
COMING DAYS. WARM, SUMMER-LIKE CONDITIONS PERSIST THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1219 PM CDT MON JUN 1 2026
VFR CONDITIONS PREVAIL TODAY, WITH CALM TO LIGHT WINDS TODAY.
WIND DIRECTION WILL BE VARIABLE TODAY, THEN PREVAILING GENERALLY
OUT OF THE EAST THIS AFTERNOON AND EVENING. A FEW SCATTERED
SHOWERS AND STORMS MAY DEVELOP OVER WESTERN IOWA THIS AFTERNOON,
BUT AREN'T EXPECTED TO IMPACT TERMINALS AT THIS TIME.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...DODSON
LONG TERM...DODSON
AVIATION...DODSON
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