718
FXUS63 KDMX 100812
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
312 AM CDT FRI JUL 10 2026
KEY MESSAGES
- PATCHY FOG WILL PERSIST THROUGH MID-MORNING BEFORE
DIMINISHING.
- SCATTERED SHOWERS AND STORMS WILL RE-DEVELOP THIS AFTERNOON,
MOST NUMEROUS ALONG THE IOWA/MISSOURI STATE-LINE. WHILE AN
ISOLATED STRONG STORM IS POSSIBLE, WIDESPREAD SEVERE WEATHER
IS NOT EXPECTED. SPOTTY HEAVY DOWNPOURS ARE ALSO LIKELY.
- A STRONG UPPER LEVEL HIGH PRESSURE RIDGE WILL SET UP OVER THE
CENTRAL U.S. THIS WEEKEND INTO NEXT WEEK, BRINGING MOSTLY DRY
CONDITIONS AND VERY WARM TEMPERATURES SUNDAY AND BEYOND.
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 250 AM CDT FRI JUL 10 2026
THE UPPER AIR PATTERN EARLY THIS MORNING IS DOMINATED BY A
STRENGTHENING RIDGE OF HIGH PRESSURE OVER THE ROCKIES, WITH A
NWLY FLOW REGIME OVER THE MIDWEST. THE SFC PATTERN IS VERY
DIFFUSE OVER IA, WITH VIRTUALLY NO CHANGE IN SFC PRESSURE, WHICH
IS RESULTING IN THE VERY LIGHT TO CALM WINDS IN MOST LOCATIONS.
WHILE THERE WERE VERY ISOLATED SHOWERS OVERNIGHT ACROSS IOWA,
THE FEATURES OF GREATEST INTEREST ON RADAR ARE THE CLUSTERS OF
SHOWERS AND TSTMS OVER NE AND KS.
TODAY, STILL EXPECTING PATCHY FOG ACROSS THE AREA THROUGH MID-
MORNING. OTHERWISE, THE CONSENSUS OF THE SHORT TERM GLOBAL AND CAM
SOLUTIONS DEVELOP A REMNANT MCV OUT OF THE CONVECTION IN NE/KS AND
TRACK THAT FEATURE ACROSS NRN MO AND SRN IA FROM LATE MORNING THRU
EVENING. THE THERMODYNAMIC ENVIRONMENT TODAY WILL BE SIMILAR TO
YESTERDAY, WITH GENERALLY WEAK CAPPING, 1000-1500 J/KG OF MLCAPE,
AND A WEAK DEEP LAYER SHEAR PROFILE /<25 KTS/. WHILE THE EXTENT OF
FORCING AND RESULTING IMPACTS FROM MCV'S CAN BE TRICKY TO FORECAST,
A MAJORITY OF THE CAM SOLUTIONS DEVELOP AT LEAST SCATTERED SHOWERS
AND THUNDERSTORMS /30% TO 60%/ ACROSS SOUTHERN IOWA. NORTH OF
INTERSTATE 80, COVERAGE OF STORMS SHOULD BE LESS, GENERALLY <20%.
AS NOTED, THE LOW LEVEL FLOW BELOW 700MB IN THIS REGIME IS VERY
WEAK, WITH SOME INCREASE IN WIND SPEEDS ABOVE 500MB. THIS LACK
OF STRONGER FLOW/SHEAR SHOULD LIMIT THE ORGANIZATION OF STORMS
IN IOWA, WITH MOST MODELS SHOWING BETTER SHEAR ACROSS NORTHERN
MO, WHERE THE SPC DOES HAVE A MARGINAL/SLIGHT RISK. IT SHOULD BE
NOTED THAT A FEW CAMS /HRRR, ARW, FV3/ DO PRODUCE STRONGER
WINDS OF 50-60 MPH, MOSTLY ACROSS MISSOURI, BUT GETTING
DANGEROUSLY CLOSE TO THE STATE LINE. THIS IS SOMETHING WE'LL
NEED TO WATCH CLOSELY THIS PM. IN ADDITION, WITH THE WARM AND
HUMID, AIRMASS IN PLACE /PWATS STILL ~ 1.5"/ A FEW POCKETS OF
HEAVY RAINFALL ARE POSSIBLE. LITTLE CHANGE IN HIGH TEMPERATURES
TODAY WITH LIMITED TEMP ADVECTION, SO STILL EXPECTING READINGS
IN THE MID 80S. IN FACT, IF THICKER CLOUDS DEVELOP, WE MAYBE A
TOUCH TOO WARM WITH HIGHS, ESPECIALLY IN THE SOUTH.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING, THE SHOWER AND
THUNDERSTORM ACTIVITY WILL DIMINISH WITH CLEAR TO PARTLY CLOUDY
SKIES. PATCHY FOG WILL ONCE AGAIN BE POSSIBLE, BUT AT THIS POINT NO
CLEAR SIGNALS ON WIDESPREAD DENSE FOG.
SATURDAY...RISING UPPER LEVEL HEIGHTS AT H5 BEGIN TO BUILD INTO
THE REGION FROM THE WEST, WHILE SFC HIGH PRESSURE EXPANDS INTO
IOWA FROM THE GREAT LAKES REGION. AS SUCH, EXPECTING MOSTLY DRY
CONDITIONS WITH ANY SHOWERS/TSTMS FOCUSED SOUTH AND EAST OF THE
FORECAST AREA. WITH A LIGHT E/NELY SFC WINDS NOT EXPECTING MUCH
CHANGE IN TEMPS ON SATURDAY WITH HIGHS AGAIN IN THE MID-80S.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ISSUED AT 232 PM CDT THU JUL 9 2026
THIS WEEKEND AND INTO EARLY NEXT WEEK, A MID TO UPPER LEVEL RIDGE IS
EXPECTED TO BUILD ACROSS THE CENTRAL AND NORTHERN PLAINS. THIS WILL
DRIVE A WARMING TREND ALONGSIDE RELATIVELY DRY CONDITIONS ACROSS THE
REGION. HIGHS ON SATURDAY WILL APPROACH THE MID-80S WITH UPPER 80S
EXPECTED BY SUNDAY. AS WE HEAD INTO THE NEW WORK WEEK, MOST OF
OUR CENTRAL IOWA WILL PUSH INTO THE LOWER 90S. ALONG WITH THE
BUILDING RIDGE, OVERNIGHT LOWS ARE EXPECTED TO REMAIN ELEVATED
IN UPPER 60S TO LOWER 70S. BY MIDWEEK, DAYTIME HIGHS WILL PEAK
IN THE LOWER TO MID 90S AS THE DRY SPELL CONTINUES. HEAT INDICES
COULD PUSH MID TO UPPER 90S IN A FEW SPOTS.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1058 PM CDT THU JUL 9 2026
TRENDED MORE AGGRESSIVE WITH FOG AS CALM WINDS ALLOWED FOR
PATCHY FOG TO FORM OVER MUCH OF THE AREA. ADDED A TEMPO GROUP
FOR MVFR FOR KDSM AND KOTM, THEN WORSENED FOG CONDITIONS FOR
KALO AND KMCW.
ALSO OF NOTE IS NEAR STATIONARY SHOWERS NEAR KALO THAT HAVE HELD
ON. ADDED A TEMPO FOR THEM AT THE BEGINNING.
FOG WILL LIFT TO STRATUS THROUGH THE MORNING, WHICH WILL LIKELY
REQUIRE A SHORT (2-3 HOUR) MVFR CIG GROUP IN THE NEXT ISSUANCE.
THEY'LL BECOME SCT THROUGH THE AFTERNOON. WIDELY SCATTERED
THUNDERSTORMS STILL ANTICIPATED NEAR KOTM AFTER 20Z, BUT
COVERAGE IS TOO SPARSE TO INCLUDE IN THE TAF AT THIS RANGE.
HYDROLOGY
ISSUED AT 232 PM CDT THU JUL 9 2026
MAIN HYDROLOGIC FOCUS IS NOW ON RIVER FLOOD POTENTIAL WITHIN THE
CEDAR BASIN, ESPECIALLY THE SHELL ROCK AND CEDAR RIVERS. HIGH
RAINFALL AMOUNTS OCCURRED IN THE UPPER CEDAR BASIN LAST NIGHT, AND
QUESTIONS EXIST REGARDING THE EVOLUTION OF THE CREST AS IT TRAVELS
DOWNSTREAM.
FOR THE SHELL ROCK RIVER, A QUICK RISE HAS OCCURRED DURING THE DAY
AND THE CREST HAS BEEN TRAVELING DOWNSTREAM. IT IS EXPECTED IN THE
SHELL ROCK AREA LATER TODAY OR THIS EVENING.
FOR THE CEDAR RIVER, CURRENT RIVER FORECASTS REFLECT A SHORTER-LIVED
BUT HIGHER CREST, VS. A LONGER-LIVED BUT BROADER CREST. RECOGNIZING
THE POTENTIAL MAGNITUDE OF THIS EVENT ESPECIALLY IN THE WFO LA
CROSSE SERVICE AREA, THE U.S. GEOLOGICAL SURVEY IS PLANNING TO MAKE
SOME EXTRA FLOW MEASUREMENTS WHICH WILL HELP PROVIDE A MORE
COMPREHENSIVE PICTURE OF THE STREAM'S RESPONSE FOR THIS EVENT. THIS
INFORMATION WILL HELP FINE-TUNE DOWNSTREAM FORECASTS FOR EXAMPLE IN
THE WATERLOO-CEDAR FALLS AREA.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...FOWLE
LONG TERM...05/TDR
AVIATION...JIMENEZ
HYDROLOGY...ZOGG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page