924
FXUS63 KDMX 132328
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
628 PM CDT WED MAY 13 2026
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- DRY, QUIET, AND GENERALLY PLEASANT WEATHER THROUGH THURSDAY
MORNING. LOWS IN THE MID-40S TO LOWER 50S TONIGHT.
- BREEZY ON THURSDAY WITH SOME SHOWERS AND STORMS LATE IN THE
DAY INTO THURSDAY NIGHT. A FEW STRONG TO SEVERE STORMS MAY BE
POSSIBLE IN SOUTHERN IOWA, NEAR THE MISSOURI BORDER AFTER DARK.
- WARMER AND MORE ACTIVE AT TIMES FROM LATER FRIDAY INTO EARLY
NEXT WEEK. HIGHS GENERALLY IN THE 80S EACH DAY AND MAY TOUCH
90 IN SOME PLACES. SEVERAL ROUNDS OF THUNDERSTORMS FROM FRIDAY
NIGHT THROUGH MONDAY.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 255 PM CDT WED MAY 13 2026
HIGH PRESSURE MOVING ACROSS THE STATE TODAY HAS LED TO A BEAUTIFUL
DAY WITH TEMPERATURES MAINLY IN THE 70S EARLY THIS AFTERNOON UNDER
CLEAR SKIES. BREEZY WINDS HAVE DEVELOPED IN MUCH OF THE AREA AHEAD
OF THE HIGH PRESSURE WITH WINDS OUT OF THE NORTH-NORTHWEST SUSTAINED
AROUND 10-20 MPH AND GUSTS TO 25-35 MPH, BUT THESE WINDS HAVE
ALREADY STARTED TO DECREASE IN WESTERN IOWA AND WILL CONTINUE TO
DIMINISH INTO THIS EVENING. UNDER THE CLEAR SKIES, TEMPERATURES WILL
ALSO FALL OFF TONIGHT BUT ARE MITIGATED FROM BOTTOMING OUT TOO FAR
WITH WINDS SHIFTING TO BE OUT OF THE SOUTHEAST LATE THIS EVENING AND
INCREASING AGAIN INTO THURSDAY MORNING. TEMPERATURES WILL BE COOLEST
IN THE EAST CLOSEST TO THE HIGH PRESSURE WHERE WINDS WILL REMAIN
LIGHTER LONGER WITH LOWS IN THE 40S IN THE EAST TO 50S IN THE WEST.
THURSDAY WILL START OUT PLEASANT AGAIN THOUGH WINDS WILL QUICKLY
RAMP UP AS THE PRESSURE GRADIENT TIGHTENS. AS NOTED IN THE PREVIOUS
DISCUSSION, MIXING IS NOT AS EFFICIENT AS MONDAY WHICH WILL KEEP
WINDS FROM BECOMING TOO STRONG, BUT SUSTAINED WINDS WILL STILL BE
AROUND 15-30 MPH WITH GUSTS TO NEAR 40 MPH, THE HIGHEST WINDS AND
GUSTS IN WESTERN IOWA. RELATIVE HUMIDITY WILL ALSO FALL TO AROUND
THE 25-30% RANGE WITH THE DRY CONDITIONS PERSISTING LEADING TO
ELEVATED FIRE WEATHER CONDITIONS AGAIN, THOUGH MITIGATED BY THE
GREEN SURFACE FUELS IN ADDITION TO THE LESS EFFICIENT MIXING. WE
COULD SEE LOCALIZED BLOWING DUST AGAIN WITH THE HIGHER WINDS
THURSDAY, ESPECIALLY WHERE ANY OPEN FIELDS WERE RECENTLY PLOWED. THE
WIND DIRECTION MAY NOT BE QUITE AS FAVORABLE AS MONDAY BRINGING DUST
IN FROM THE NORTHWEST, BUT DON'T WANT TO RULE OUT LOCALIZED
VISIBILITY DROPS NEAR TO UNDER 1 MILE WITH NO RECENT RAIN TO WET THE
DUST.
THETA-E ADVECTION INCREASES THROUGH THE DAY THURSDAY AHEAD OF THE
FIRST IN A SERIES OF IMPULSES THAT WILL MOVE THROUGH THE REGION INTO
EARLY NEXT WEEK. THIS WILL START OFF AN ACTIVE PERIOD FROM THURSDAY
NIGHT THROUGH THE WEEKEND AND SLIGHTLY BEYOND. CAMS ALL START TO
KICK OFF SHOWERS IN PLACES BY THURSDAY AFTERNOON THOUGH LOOKING
CLOSER AT FORECAST SOUNDINGS INDICATES A LOT OF DRY AIR TO OVERCOME.
A FEW SHOWERS OR SPRINKLES WITH AN ISOLATED RUMBLE OF THUNDER MAY BE
ABLE TO REACH THE GROUND IN PORTIONS OF NORTHERN IOWA IN THE
AFTERNOON. THE HIGHER STORM CHANCES FOR THURSDAY NIGHT ARE IN
SOUTHERN IOWA AND LATE IN THE EVENING, WELL AFTER DARK, WITH THE LLJ
RAMPING UP AND A BIGGER PUSH OF THETA-E ADVECTION MOVING THROUGH.
THE COVERAGE OF OF THESE STORMS REMAINS UNCERTAIN WITH THE BULK OF
THE ACTIVITY NEAR TO JUST SOUTH OF THE IA/MO BORDER. SHOULD STORMS
CREEP INTO IOWA, A FEW MAY BE ABLE TO BE STRONG TO SEVERE WITH HAIL
AND GUSTY WINDS IN MAINLY FAR SOUTHERN IOWA WHERE LIMITED BUT STILL
PRESENT MUCAPE LESS THAN 1000 J/KG PAIRS WITH 30-40 KNOTS OF BULK
SHEAR.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 255 PM CDT WED MAY 13 2026
DRY BUT MUCH WARMER CONDITIONS ARE FORECASTED ON FRIDAY AS THE
THERMAL RIDGE NUDGES CLOSER TO THE AREA AND HIGHS SURGE INTO THE 80S
TO POTENTIALLY TOUCHING 90 IN PORTIONS OF SOUTHWEST IOWA. CLOUDS AND
STORM CHANCES THEN RETURN FRIDAY NIGHT INTO EARLY SATURDAY AS A
FRONT MOVES INTO THE STATE. THESE STORMS WILL BE FIGHTING A HIGH
PRESSURE IN THE NORTH AND DRY AIR. MODELS STILL HAVE A FAIR AMOUNT
OF DISAGREEMENT IN THE SOUTH IN THE TIMING AND LOCATION OF THE NEXT
SLUG OF THETA-E ADVECTION AND THE LLJ IS NOT FAVORABLY POSITIONED.
THE DEEP MOISTURE OFF THE GULF IS ALSO SHUNTED OFF TO THE EAST IN
THE LOW TO MID LEVELS POTENTIALLY PUSHING THE GREATEST STORM THREAT
TO THE EAST AS CONDITIONS WERE LOOKING THIS TIME YESTERDAY, THOUGH
MODELS ARE ALSO FURTHER NORTH THAN THEY WERE YESTERDAY WITH
BALLOONING INSTABILITY AND STILL SUFFICIENT SHEAR IN SOUTHERN IOWA.
CERTAINLY CANNOT RULE OUT SOME STRONG TO SEVERE STORMS, BUT THE
MESOSCALE DETAILS REMAIN A BIT TOO UNCERTAIN AT THIS POINT WITH
REFINEMENTS LIKELY. THE SPC DOES HAVE A MARGINAL RISK (LEVEL 1 OUT
OF 5) FOR A GOOD PORTION OF THE AREA AND A SLIGHT RISK (LEVEL 2 OUT
OF 5) IN THE FAR SOUTH/SOUTHEAST ON LATE FRIDAY INTO SATURDAY.
THE ACTIVE PATTERN REMAINS THROUGH THE WEEKEND WITH ADDITIONAL STORM
CHANCES LATER SATURDAY INTO SUNDAY, AND AGAIN LATER SUNDAY INTO
MONDAY, AND ON MONDAY. SPC HAS ALL 3 OF THESE PERIODS (SATURDAY,
SUNDAY, MONDAY) WITH A 15% RISK. IT IS LIKELY THAT WHAT HAPPENS THE
PREVIOUS DAY WILL SOMEWHAT DICTATE WHAT HAPPENS IN SUBSEQUENT DAYS.
WILL CONTINUE TO WATCH THESE PERIODS CLOSELY AND PROVIDE ADDITIONAL
DETAILS IN THE COMING DAYS. TEMPERATURES WILL REMAIN WARM AND AT
LEAST IN THE 80S THROUGH THE WEEKEND. THESE TEMPERATURES WERE HELD
DOWN A BIT FROM NBM WITH NBM ON THE HIGH END OF THE TEMPERATURE
DISTRIBUTION AND LIKELY AFFECTED BY STORMS AND CLOUD DEBRIS AT
TIMES.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 626 PM CDT WED MAY 13 2026
A FEW REMAINING VFR CUMULUS ARE CURRENTLY DISSIPATING ACROSS THE
STATE ALONG WITH GUSTY WINDS BEGINNING TO CALM. <8 KNOT SUSTAINED
NORTHERLY WINDS WILL SHIFT SOUTHEASTERLY THROUGH THE EVENING AND
OVERNIGHT. WINDS COULD GET FAIRLY GUSTY TOMORROW AFTERNOON, WITH
HIGH CONFIDENCE OF GUSTS ON THE ORDER OF 20-25 KNOTS AND PERHAPS AT
TIMES PUSHING 30 KNOTS. A 6-8 KFT CIG IS EXPECTED TO MOVE WEST TO
EAST THROUGH THE AFTERNOON, ALONG WITH SOME MARGINAL SHOWER CHANCES,
THOUGH TIMING AND COVERAGE IS UNCERTAIN ENOUGH TO LEAVE OUT OF THE
TAFS FOR THIS ISSUANCE.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...05
LONG TERM...05
AVIATION...BURY/DE BRUIN
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