822
FXUS63 KDMX 242330
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
530 PM CST WED DEC 24 2025
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- AREAS OF FOG THROUGH CHRISTMAS DAY AND NIGHT. DENSE FOG COULD
DEVELOP, MAINLY OVER WEST AND SOUTHWEST IOWA.
- ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGH SATURDAY.
- COLDER WITH GUSTY WINDS AND SNOW SHOWERS ON SUNDAY.
DISCUSSION
ISSUED AT 224 PM CST WED DEC 24 2025
MUCH OF THE FORECAST WAS FOCUSED ON TONIGHT AND TOMORROW AND ANY
IMPACTS FOG COULD HAVE ON HOLIDAY TRAVEL. HIGHER DEW POINTS HAVE
BEEN ADVECTING INTO IOWA TODAY WITH VALUES IN THE 40S TO NEAR 50
OVER THE SOUTHWEST THIRD OF THE STATE. FOG HAS BEEN DEVELOPING IN
AREAS WHERE THESE DEW POINTS BEGIN TO EXCEED GROUND TEMPERATURES.
DENSE FOG HAS ALREADY DEVELOPED OVER PARTS OF NORTHWEST IOWA AS DEW
POINTS IN THE MID TO UPPER 30S MOVE OVER AREAS WITH 1 INCH OR MORE
OF SNOW COVER. THIS ADVECTION OF DEW POINTS NORTHWARD WILL SLOW THIS
EVENING THEN BEGIN TO RETREAT SOME BACK TO THE SOUTH. THIS LEADS TO
THE QUESTION IF THE DENSE FOG WILL PERSIST OVER NORTHWEST IOWA AS
THE DEW POINTS BEGIN TO SETTLE BACK TOWARDS FREEZING. TYPICALLY,
WIDESPREAD DENSE FOG DOES NOT FORM UNDER STRATUS WITHOUT LOW LEVEL
MOISTURE ADVECTION SO IT IS POSSIBLE THAT AREAS OF DENSE FOG WILL BE
MORE CLOSELY ASSOCIATED WITH THE CLEARING AREAS THAT ARE BEGINNING
TO OCCUR OVER NEBRASKA AND FAR WESTERN IOWA. OVERALL, EXPECT FOG TO
DEVELOP WITH VISIBILITIES DROPPING BELOW ONE MILE AND SOME POCKETS
OF ONE QUARTER MILE OR LESS. MORE WIDESPREAD DENSE FOG COULD REACH
THE WEST/FAR SOUTHWEST CLOSER TO THE CLEARING AREAS. AT THIS POINT,
PLAN TO REMAIN HEADLINE FREE DUE TO SOME UNCERTAINTY AND THIS WILL
ALLOW FOR FOLLOWING SHIFTS TO BETTER ALIGN ANY NEEDED HEADLINES. THE
FOG WILL SLOWLY IMPROVE CHRISTMAS MORNING BEFORE REDEVELOPING IN THE
EVENING WITH ALL OF THIS MOISTURE BELOW A STEEP LOW LEVEL INVERSION.
LIGHT DRIZZLE COULD OCCUR, PARTICULARLY THURSDAY NIGHT OVER THE
SOUTH CLOSER THE SURFACE BOUNDARY AND WHEN DEEP MOISTURE AND MORE
FAVORABLE VERTICAL ASCENT AND MOIST LAYER SHEAR, ARE IN PLACE.
OTHERWISE, MOISTURE DEPTHS ARE MEAGER OVERALL AT LESS THAN 3 KFT AND
ONLY WEAK FORCING LEADING TO ONLY PATCH LIGHT DRIZZLE.
NARROWED THE DIURNAL RANGE FOR TONIGHT AND TOMORROW BY TRENDING LOW
TEMPERATURES TONIGHT CLOSER TO THE NBM 75TH PERCENTILE AND TOMORROWS
HIGHS NEAR THE 25TH PERCENTILE. TEMPERATURES UNDER THIS STRATUS WILL
BE CLOSELY RELATED TO THE DEW POINT TEMPERATURES AND MAINLY WITHIN 1
TO 4 DEGREES. THE NBM CONTINUES TO SUGGEST VERY MILD TEMPERATURES FOR
FRIDAY AND SATURDAY. IT IS NOT A FORGONE CONCLUSION THAT THIS
STRATUS WILL COMPLETELY MOVE OUT OF IOWA WHILE A SUBSTANTIAL LOW
LEVEL INVERSION REMAINS. ESPECIALLY SATURDAY WHEN ANOTHER SURGE OF
LOW LEVEL MOISTURE LIFTS INTO IOWA WITH DEW POINTS IN THE 40S TO
PERHAPS EVEN 50 SOUTH. A COLD FRONT MOVES THROUGH SATURDAY NIGHT
BRINGING COLDER TEMPERATURES, GUSTY WINDS AND PERHAPS SNOW SHOWERS
TO THE STATE.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 529 PM CST WED DEC 24 2025
WIDESPREAD FOG WILL CONTINUE TO SPREAD ACROSS MUCH OF CENTRAL
IOWA THIS EVENING AND REMAIN INTO THURSDAY MORNING, WITH MOST
SITES EXPECTED TO EXPERIENCE VISIBILITIES NEAR TO BELOW A HALF
TO QUARTER MILE, ALONG WITH LOW CEILINGS LEADING TO WIDESPREAD
IFR/LIFR CONDITIONS. THOUGH FOG IS EXPECTED TO LIFT NEAR THE MID
MORNING TIMEFRAME, LOW CEILINGS ARE EXPECTED TO CONTINUE, WITH
ANOTHER POTENTIAL FOR ADDITIONAL WIDESPREAD FOG NEAR THE END OF
THE CURRENT TAF PERIOD AS MOISTURE LINGERS ACROSS THE STATE.
DMX WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR IAZ004-005-015-
023-024-033-034.
DISCUSSION...DONAVON
AVIATION...BURY
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