545
FXUS63 KDMX 011730
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1230 PM CDT FRI AUG 1 2025
...UPDATED FOR THE 18Z AVIATION DISCUSSION...
KEY MESSAGES
- QUIET AND COOL CONDITIONS INTO THE WEEKEND, WITH HAZY SKIES AT
LEAST THROUGH TONIGHT
- LOW CHANCES (<30%) FOR SHOWERS MAINLY OVER WESTERN IOWA SUNDAY
INTO NEXT WEEK
- TEMPERATURES WARM TOWARD THE MIDDLE OF NEXT WEEK AND BEYOND,
WITH A FEW LOW CHANCES (<30%) FOR SHOWERS AND STORMS
UPDATE
ISSUED AT 239 AM CDT FRI AUG 1 2025
SMOKE CONTINUES TO AFFECT THE REGION AND IS CONTRIBUTING TO
LIGHTLY REDUCED VISIBILITY AT MANY LOCATIONS IN OUR FORECAST
AREA. HAVE MAINTAINED AND EXPANDED AREAS OF SMOKE ACROSS THE
AREA THROUGH TONIGHT, AND THE AIR QUALITY ALERT REMAINS IN
EFFECT. SMOKE MAY LINGER INTO THE WEEKEND AS WELL - THIS WILL BE
ASSESSED ON SUBSEQUENT SHIFTS.
DISCUSSION
ISSUED AT 237 PM CDT THU JUL 31 2025
SURFACE ANALYSIS DEPICTS A WIDE AREA OF HIGH PRESSURE CENTERED OVER
NORTHERN MINNESOTA THAT IS COVERING MUCH OF THE MIDWEST REGION
TODAY, WHICH HAS LED TO DRY AND OVERALL QUIET WEATHER ACROSS IOWA, A
VERY MUCH SO WELCOMED CHANGE FOLLOWING THE ACTIVE WEATHER OVER THE
LAST SEVERAL DAYS. HOWEVER, AS THE WINDS REMAIN OUT OF THE
EAST/NORTHEAST, CANADIAN WILDFIRE SMOKE WILL CONTINUE TO TRACK OVER
MUCH OF THE MIDWEST INCLUDING IOWA, WITH WIDESPREAD HAZE BEING
REPORTED NEAR/AT THE SURFACE GIVEN THE SUBSIDENCE ONGOING ACROSS THE
REGION, WITH VISIBILITIES AROUND 4-5 MILES IN MANY LOCATIONS. MODEL
GUIDANCE CONTINUES TO DEPICT SMOKE REMAINING OVERHEAD AT LEAST
THROUGH FRIDAY AS THE FLOW PATTERN LARGELY REMAINS UNCHANGED, HENCE
THE ISSUANCE OF THE AIR QUALITY ALERT VIA THE IOWA DNR THAT IS IN
EFFECT NOW UNTIL MIDNIGHT FRIDAY NIGHT FOR ALL OF IOWA. OUTSIDE
OF THE SMOKE, TEMPERATURES WILL REMAIN MORE ON THE COMFORTABLE
SIDE FOR LATE JULY/EARLY AUGUST WITH HIGHS TODAY INTO THE
WEEKEND TOPPING OUT IN THE MID TO UPPER 70S. THERE IS A SIGNAL
GIVEN CLEAR SKIES, LIGHT WINDS AND RESIDUAL MOISTURE OVER
NORTHERN IOWA FOR PATCHY FOG TONIGHT INTO FRIDAY MORNING, BUT
ANY FOG WOULD DISSIPATE AFTER SUNRISE.
BY SATURDAY, THE HIGH PRESSURE IS EXPECTED TO SLOWLY TRACK EAST OUT
OF THE REGION, WITH A 500MB TROUGH FURTHER WEST INTO THE DAKOTAS
ENTERING INTO THE MIDWEST BY THE EVENING. THIS SYSTEM GENERALLY
LOOKS TO TRY AND STRENGTHEN INTO SUNDAY, WITH GUIDANCE DEPICTING
SHOWERS DEVELOPING OVER EASTERN NEBRASKA/SOUTH DAKOTA INTO WESTERN
IOWA BY SUNDAY MORNING. MODEL SOUNDINGS INDICATE THAT LOW LEVEL DRY
AIR WOULD LIMIT SHOWERS FROM MOVING FURTHER EAST INTO THE STATE FOR
SUNDAY AND INTO MONDAY, WITH GENERALLY WEAK FORCING WITH THE
BOUNDARY AS IT STRUGGLES TO BRING RAINFALL INTO THE STATE. CAN'T
RULE OUT A FEW WINDOWS DURING THIS TIME FRAME FOR AT LEAST SOME
ISOLATED TO SCATTERED LIGHT SHOWERS AT TIMES THROUGH TUESDAY, WITH
RAINFALL AMOUNTS GENERALLY OF A FEW TENTHS OR LESS. MODELS ALSO
INDICATE THAT THE AXIS OF INSTABILITY AND SHEAR GENERALLY REMAINS
WEST OF THE STATE INTO NEXT WEEK, WHICH WILL LIMIT ANY CONCERN FOR
SEVERE WEATHER. TEMPERATURES OTHERWISE WILL REMAIN COOLER IN THE
UPPER 70S TO LOW 80S INTO THE NEXT WORK WEEK. CHANGES LOOK TO TAKE
PLACE BY MID-WEEK, AS INCREASING SOUTHWESTERLY FLOW IS EXPECTED TO
BRING A RETURN TO WARMER TEMPERATURES BACK THROUGH THE 80S, WITH A
FEW ADDITIONAL SYSTEMS LOOKING TO BRING SHOWER AND STORM CHANCES
INTO THE AREA. MORE TO COME ON THESE DETAILS OVER THE NEXT SEVERAL
DAYS.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1219 PM CDT FRI AUG 1 2025
VFR CONDITIONS HAVE DEVELOPED TODAY AS SMOKE CONCENTRATIONS AT
THE SURFACE DIMINISH, ALBEIT STILL PRODUCING VFR VISIBILITY
REDUCTIONS AROUND 6 TO 8 SM. THERE MAY STILL BE BRIEF PERIODS
OF LESS THAN 6SM VISIBILITIES DUE TO SMOKE STILL TODAY, BUT
SHOULD GENERALLY REMAIN VFR. FEW TO SCATTERED VFR CUMULUS HAS
ALSO DEVELOPED THIS AFTERNOON, AND WILL PERSIST THROUGH THE
DAYLIGHT HOURS. REDUCED VISIBILITIES DUE TO SMOKE AND/OR FOG
MAY DEVELOP AGAIN OVERNIGHT TONIGHT INTO EARLY TOMORROW MORNING.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...LEE
DISCUSSION...BURY
AVIATION...DODSON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page