208
FXUS63 KDMX 100738
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
238 AM CDT SUN MAY 10 2026
KEY MESSAGES
- DRY AND RELATIVELY COOL TODAY, THEN TEMPERATURES FALLING
TONIGHT AND REACHING THE 30S IN NORTHERN AND EASTERN IOWA
WHERE A FROST OR FREEZE MAY BE POSSIBLE EARLY MONDAY MORNING.
- WARMER TEMPERATURES WILL RETURN FOR MOST OF THE COMING WEEK,
ALONG WITH SOME SHOWER AND THUNDERSTORM CHANCES (25-35%) LATE
MONDAY NIGHT INTO TUESDAY. A FEW STRONG STORMS COULD BE
POSSIBLE, BUT THE SEVERE WEATHER THREAT IS LIMITED.
- BREEZY CONDITIONS ARE FORECAST ON TUESDAY, ESPECIALLY IN
NORTHERN IOWA DURING THE AFTERNOON WHERE WIND GUSTS TO NEAR 40
MPH ARE EXPECTED. DRY CONDITIONS WILL ALSO CONTINUE DURING
THIS TIME, WITH RELATIVE HUMIDITY FALLING BELOW 25% AT TIMES.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED AT 238 AM CDT SUN MAY 10 2026
A LARGE HIGH PRESSURE AREA WILL BUILD SOUTHWARD INTO THE REGION
TODAY, BRINGING DRY AND SOMEWHAT COOLER WEATHER. SOME MID-LEVEL
CLOUDS MAY DEVELOP AT TIMES, BUT IN GENERAL SKIES SHOULD REMAIN
PARTLY TO MOSTLY SUNNY WITH TEMPERATURES PEAKING AROUND 70S.
WINDS WILL BE LIGHT THIS MORNING, BUT DURING THE AFTERNOON
TURBULENT MIXING WILL RESULT IN INCREASINGLY GUSTY NORTH
NORTHWEST BREEZES OVER NORTHERN IOWA, WITH SUSTAINED SPEEDS OF
AROUND 15 MPH AND GUSTS TO 25 MPH. TONIGHT, AS THE CORE OF THE
HIGH PRESSURE RIDGE SLIDES BY JUST TO OUR NORTHEAST, WINDS WILL
TURN TOWARD NORTHEASTERLY AND GO LIGHT AGAIN OVERNIGHT. IN OUR
SOUTHERN AND WESTERN COUNTIES A BIT FARTHER FROM THE HIGH WINDS
WILL STAY SLIGHTLY MORE ORGANIZED AND SOME LINGERING CLOUDS MAY
MITIGATE RADIATIONAL COOLING, BUT TEMPERATURES THERE WILL STILL
LIKELY FALL INTO THE LOW TO MID-40S. HOWEVER, IN OUR
NORTHEASTERN COUNTIES SKIES ARE MORE LIKELY TO CLEAR AND WINDS
MAY GO CALM CLOSER TO THE RIDGE AXIS, WITH TEMPERATURES FALLING
INTO THE 30S AND POSSIBLY EVEN REACH FREEZING LEVELS IN A FEW
SPOTS. IF CONFIDENCE IN THIS OUTCOME INCREASES FURTHER TODAY,
THEN A FROST OR FREEZE HEADLINE MAY BECOME WARRANTED FOR PARTS
OF NORTHERN AND EASTERN IOWA EARLY MONDAY MORNING.
ON MONDAY THE BROADLY CYCLONIC STEERING FLOW THAT HAS BEEN IN
PLACE OVER IOWA SINCE LATE LAST WEEK WILL FINALLY BEGIN TO MOVE
OFF TO THE EAST, BUT RIGHT ON ITS HEELS A RATHER ENERGETIC
SHORTWAVE TROUGH WILL OVERTOP THE ROCKIES ALONG THE U.S./CANADA
BORDER, THEN ON MONDAY NIGHT WILL DIVE SOUTHEASTWARD INTO NORTH
DAKOTA AND MINNESOTA. AHEAD OF THIS FEATURE, DURING THE DAY ON
MONDAY BRIEF RIDGING WILL MOVE OVER THE MIDWEST AND ALLOW FOR
WARMER TEMPERATURES AND WINDS TURNING BACK AROUND TOWARD SOUTH
LATE IN THE DAY. THE SOUTHERLY BREEZES WILL THEN INCREASE MONDAY
NIGHT AHEAD OF THE APPROACHING SHORTWAVE TROUGH, KEEPING
TEMPERATURES WARM OVERNIGHT WITH LOWS ONLY IN THE 50S. AS THE
SHORTWAVE NEARS THE IOWA/MINNESOTA BORDER EARLY TUESDAY MORNING,
IT WILL PUSH A TRAILING SURFACE BOUNDARY SOUTHEASTWARD INTO THE
REGION. AROUND OR SHORTLY BEFORE SUNRISE TUESDAY, INCREASING
WARM AIR AND MOISTURE ADVECTION AHEAD OF THIS BOUNDARY SHOULD BE
SUFFICIENT TO GENERATE SOME SHOWERS AND PERHAPS A FEW
THUNDERSTORMS OVER NORTHERN IOWA.
THE BOUNDARY WILL PROGRESS THROUGH THE REMAINDER OF OUR FORECAST
AREA DURING THE DAY TUESDAY, THOUGH THE EXACT TIMING IS STILL
VARIABLE IN DETERMINISTIC MODEL SOLUTIONS. TEMPERATURES WILL
WARM NICELY ACROSS THE AREA ON TUESDAY, REACHING THE LOWER TO
PERHAPS MID-80S IN CENTRAL AND SOUTHERN IOWA AHEAD OF THE
BOUNDARY, AND EVEN UPPER 70S BEHIND IT IN THE NORTH AS COLD AIR
ADVECTION IS NEGLIGIBLE. DIURNAL DESTABILIZATION LEADS TO
THUNDERSTORM CONCERNS ALONG THE BOUNDARY DURING THE DAY,
HOWEVER, THERE ARE SEVERAL MITIGATING FACTORS TO CONSIDER. ONE
IS THAT THE BEST UPPER-LEVEL SUPPORT WILL BE TRANSLATING
NORTHEAST AND EAST OF OUR AREA. ANOTHER IS THAT SOME FORECAST
SOUNDINGS INDICATE A DECENT EML INVERSION THAT WILL NEED TO BE
ERODED. FINALLY, IF THE BOUNDARY PASSES THROUGH OUR AREA DURING
THE MORNING AND EARLY AFTERNOON HOURS THEN IT WILL BE LESS
LIKELY TO REALIZE MAXIMUM DESTABILIZATION TO OVERCOME THE
INVERSION. ALL IN ALL THERE IS CERTAINLY SOME POTENTIAL FOR
CONVECTION AND RAIN IN OUR AREA ON TUESDAY, HOWEVER, POPS ARE
STILL FORECAST AT ONLY 20-30% DUE TO THE MULTIPLE DETRACTING
FACTORS. ASIDE FROM THESE CONCERNS, IT WILL ALSO BE QUITE BREEZY
BY TUESDAY AFTERNOON BEHIND THE BOUNDARY, WITH A DEEP MIXED
LAYER UP TO NEAR 700 MB AND A DEEP LAYER OF 25-35 KT WINDS JUST
ABOVE THE SURFACE. THIS WILL BE PARTICULARLY PRONOUNCED OVER OUR
NORTHERN COUNTIES, WHERE NORTHWESTERLY WINDS OF AROUND 25 TO
PERHAPS 30 MPH ARE EXPECTED, WITH GUSTS TO NEAR 40 MPH AT TIMES.
IT WILL ALSO REMAIN VERY DRY, WITH RH VALUES BELOW 25% TUESDAY
AFTERNOON, HOWEVER FIRE WEATHER CONCERNS WILL BE LIMITED DUE TO
THE GREENNESS OF MOST SURFACE FUELS.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
ISSUED AT 252 PM CDT SAT MAY 9 2026
THE MONDAY NIGHT INTO TUESDAY WAVE DEPARTS EASTWARD TUESDAY NIGHT
INTO WEDNESDAY, ALLOWING COOLER AIR TO BRIEFLY FILL IN BEHIND IT.
WITH NO MORE TROUGHS BLOCKING THE BROAD SCALE PATTERN, 500 MB
RIDGING WILL BUILD EASTWARD INTO IOWA THROUGH THE REMAINDER OF THE
WEEK. A WARMING TREND WILL THEN BEGIN THROUGH THE END OF THE WORK
WEEK, AND POTENTIALLY INTO THE WEEKEND, AS HIGHS CLIMB INTO THE 80S
THURSDAY AND FRIDAY. NBM GUIDANCE WOULD SUGGEST WE COULD EVEN BE
APPROACHING HIGHS IN THE 90S INTO NEXT WEEKEND, ALTHOUGH
DETERMINISTIC GUIDANCE DOES ADD SOME UNCERTAINTY TO THAT AS THE
PATTERN ALSO BECOMES A BIT MORE AGITATED ON THE BACKSIDE OF THE
RIDGE, BRINGING IN MULTIPLE SHORTWAVES AND MORE CHANCES FOR
SHOWERS/STORMS. THEREFORE, THE MAIN TAKEAWAY AT THIS TIME FRAME IS A
WARMING TREND THROUGH THE SECOND HALF OF THIS WEEK, AND
POTENTIALLY A MORE ACTIVE PERIOD INTO NEXT WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1220 PM CDT SAT MAY 9 2026
VFR CONDITIONS PREVAIL THROUGH THE PERIOD. LIGHT SHOWERS/SPRINKLES
ARE PASSING THROUGH THE AREA TODAY, BUT SHOULD PRODUCE MINIMAL
IMPACTS. NORTHWEST TO NORTHERLY WINDS CONTINUE THIS AFTERNOON,
SUSTAINED AROUND 15 KTS WITH GUSTS OVER 25 KTS POSSIBLE AT
TIMES. WINDS WILL BECOME LIGHT AND SOMEWHAT VARIABLE TONIGHT,
ALTHOUGH THE PREVAILING DIRECTION WILL BE OUT OF THE NORTH.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1045 PM CDT SAT MAY 9 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE END OF THIS TAF
PERIOD. SKIES ARE MOSTLY CLEAR AT ALL TERMINAL SITES THIS
EVENING AND CONFIDENCE IS HIGH THIS WILL CONTINUE THROUGH 15Z.
CLOUDS AFTER 15Z WILL START TO MOVE IN FROM THE NORTH, BRINGING
CEILINGS DOWN AT MCW AND ALO TERMINAL SITES. CONFIDENCE IS HIGH
THAT THIS WILL NOT AFFECT FLIGHT CATEGORIES. A NORTH WIND WILL
START TO ALSO INCREASE AT THIS TIME WITH WIND GUSTS REACHING
20-25KT AT FOD,ALO,MCW AND DSM. CLOUDS ARE EXPECTED TO BE
PRESENT AT THE END OF THIS TAF PERIOD AT DSM AND OTM BUT VFR
CONDITIONS WILL PREVAIL.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...LEE
LONG TERM...DODSON
AVIATION...ANSORGE/TDR
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