244
FXUS63 KDMX 210838
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 AM CDT WED MAY 21 2025
KEY MESSAGES
- GENERALLY COOL OVER THE NEXT WEEK WITH VERY LOW CHANCES FOR
SEVERE WEATHER THROUGH MOST OF THE PERIOD.
- COOL AND BREEZY TODAY, WITH LIGHT RAIN SHOWERS TODAY
NORTHEAST.
- NEXT MAIN CHANCE FOR PRECIPITATION ARRIVES THIS WEEKEND.
UPDATE
ISSUED AT 338 AM CDT WED MAY 21 2025
AREAS OF PATCHY FOG REMAINED ACROSS A HANDFUL OF SITES IN THE
NORTHEASTERN HALF OF IOWA INTO THE EARLY MORNING HOURS, GIVEN THE
LINGERING MOISTURE, WITH VISIBILITIES AROUND 1-3 STATUTE MILES.
HOWEVER, THIS FOG HAS LARGELY LIFTED AS WINDS ARE BEGINNING TO
INCREASE OUT OF THE WEST/NORTHWEST, WHICH WILL ERODE ANY REMAINING
FOG OVER THE NEXT FEW HOURS. BREEZY WINDS ARE EXPECTED TO BECOME
COMMON, WITH GUSTS GENERALLY REACHING VALUES OF 25-30 MPH BY LATE
MORNING AND GRADUALLY DECREASING BY THIS EVENING. LINGERING LIGHT
RAIN SHOWERS OVER NORTHEAST IOWA WILL GENERALLY MOVE OUT THIS
MORNING AS THE LOW PRESSURE SYSTEM THAT WAS PREVIOUSLY OVERHEAD
DEPARTS FURTHER EAST, THOUGH CHANCES (<40%) RETURN ACROSS THE
NORTHEAST INTO BY THE AFTERNOON AS A SHORTWAVE FOLLOWS BEHIND IT
THIS AFTERNOON INTO THURSDAY. ADDITIONAL ACCUMULATIONS OVER
NORTHEAST AREA WILL BE UNDER A TENTH OF AN INCH DURING THIS TIME
FRAME.
OTHERWISE, ONLY MINOR EDITS WERE MADE IN THE FORECAST, WITH NO
HAZARDOUS WEATHER EXPECTED AT THIS TIME OVER THE NEXT SEVERAL
DAYS. PLEASE REFER TO THE DISCUSSION BELOW FOR ADDITIONAL
DETAILS.
DISCUSSION
ISSUED AT 236 PM CDT TUE MAY 20 2025
LARGE AREA OF SURFACE LOW PRESSURE IS CENTERED OVER IOWA WITH A
PRONOUNCED INVERTED TROUGH EXTENDING NORTHWEST THROUGH THE DAKOTAS. A
SECONDARY VORTICITY LOBE IS ROTATING AROUND THE SOUTHERN PERIPHERY
OF THE UPPER LEVEL LOW. THAT SHORT WAVE IS MOVING ACROSS KANSAS AND
MISSOURI EARLY THIS AFTERNOON AND THIS SYSTEM IS HELPING FIRE A
SHOWERS AND STORMS OVER PARTS OF SOUTHEAST IOWA/NORTHEAST MISSOURI
AND INTO ILLINOIS. OTHER SHOWERS ARE OVER CENTRAL AND NORTH CENTRAL
IOWA. AS THIS SURFACE LOW MOVES EAST INTO TONIGHT AND WEDNESDAY, THE
INVERTED TROUGH WILL BE DRAGGED EAST, WHICH IN ITS CURRENTLY
ORIENTATION, WILL ALSO RESULT IN IT MOVING NORTH AND EAST ACROSS THE
STATE.
THE NEXT SEVERAL DAYS WEATHER WILL HAVE THE UPPER LOW TO THE NORTH
TO SHEAR OUT AND EVENTUALLY HAVE THE HUDSON BAY UPPER LOW TAKE OVER
AND SETTLE SOUTH INTO THE GREAT LAKES REGION BY THURSDAY. FOR
WEDNESDAY, WITH THE SURFACE INVERTED TROUGH NEARBY, IOWA WILL HAVE
MOSTLY CLOUDY AND VERY COOL TEMPERATURES OVER NORTHERN IOWA AND MORE
SUN AND WARMER ACROSS THE SOUTH. BY THURSDAY, THE UPPER LOW
EVOLUTION WILL LEAD TO COOL CYCLONIC FLOW OVER IOWA. A FEW PERIODS
OF LIGHT RAIN IS POSSIBLE OVER NORTHERN IOWA THROUGH WEDNESDAY NIGHT
AND A FEW SPRINKLES COULD OCCUR INTO THURSDAY. ANOTHER UPPER LEVEL
PATTERN TRANSITION WILL OCCUR LATE IN THE WEEK WITH A MORE MODIFIED
ZONAL FLOW OCCURRING THOUGH OVERALL IOWA WILL BE ON THE COOLER SIDE
OF THIS PATTERN. MOISTURE OVERRUNNING THIS COOLER AIR IS EXPECTED
THIS WEEKEND AND THAT MAY BRING THE NEXT CHANCE FOR PRECIPITATION TO
IOWA WITH THE GREATEST CHANCES OVER SOUTHERN IOWA. THESE
PRECIPITATION CHANCES MAY LINGER INTO NEXT MONDAY. TEMPERATURES FOR
LATE WEEK AND INTO EARLY NEXT WEEK WILL BE SEASONABLY COOL WITH
HIGHS IN THE 60S TO LOW 70S. MORE SIGNIFICANT WARMING SHOULD ARRIVE
BY MID NEXT WEEK WITH AN UPPER LEVEL RIDGE MOVING INTO THE
REGION.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1159 PM CDT TUE MAY 20 2025
IFR/LIFR CIGS WITH VSBY RESTRICTIONS FROM DRIZZLE TO AFFECT KMCW
AND KALO FOR AT LEAST THE NEXT 6 HOURS, EASING IN INTENSITY
THROUGH THE MORNING AND IMPROVING TO MVFR CIGS. VFR WILL RETURN
AFTER 18Z. NORTHWEST WINDS WILL HAVE GUSTS TO AROUND 20KTS UNTIL
00Z.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...BURY
DISCUSSION...DONAVON
AVIATION...JIMENEZ
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