615
FXUS63 KDMX 220819
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
319 AM CDT THU OCT 22 2026
KEY MESSAGES
-AREAS OF PATCHY FOG POSSIBLE THURSDAY MORNING ACROSS NORTHERN IOWA.
ANOTHER WARM AND DRY AFTERNOON WITH HIGHS ONCE AGAIN IN THE 70S.
-BREEZY CONDITIONS DEVELOP FRIDAY AND SATURDAY, ESPECIALLY IN
NORTHERN AND WESTERN IOWA. SOMEWHAT ELEVATED FIRE WEATHER
CONCERNS MAY DEVELOP DURING THIS TIME.
-RAIN AND RELATIVELY COOLER TEMPERATURES RETURN TO NORTHWESTERN
IOWA LATER THIS WEEKEND AND THE REMAINDER OF THE AREA EARLY
NEXT WEEK.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 318 AM CDT THU OCT 22 2026
THURSDAY MORNING
WE KICK OFF THE FOURTH THURSDAY OF OCTOBER WITH VERY SIMILAR
CONDITIONS TO PREVIOUS NIGHTS. THE STAGNANT HIGH PRESSURE THAT HAS
BEEN LOCKED IN PLACE OVER THE GREAT LAKES WILL CONTINUE TO STAY PUT
TODAY CONTINUING TO USHER IN SOUTH TO SOUTHEASTERLY WINDS. THIS HAS
BROUGHT CONTINUOUS DRY AIR INTO THE REGION AND KEPT THINGS MOSTLY
CALM.
THE MAIN CHALLENGE THIS MORNING WILL BE PATCHY FOG IN THE SAME
AREAS WHERE FOG HAS BEEN PRESENT OVER THE LAST FEW NIGHTS. DENSE FOG
IS NOT EXPECTED AS WE CONTINUE TO LACK MOISTURE BUT DUE TO CLEAR
SKIES, CALM WINDS, A FEW SPOTS COULD SEE SOME SHALLOW FOG-
ESPECIALLY IN LOW LYING AREAS AND ALONG RIVER RIVER FRONTS. FOG
SHOULD BURN OFF SHORTLY AFTER SUNRISE, AND WE WILL BE TREATED ONCE
AGAIN TO AN ABOVE-AVERAGE DAY WITH MOSTLY SUNNY SKIES.
FRIDAY
AS WE TAKE A LOOK AT LARGE SCALE FEATURES, A WEST COAST LOW
PRESSURE SYSTEM IS EXPECTED TO COME ASHORE OVER CALIFORNIA LATER
THURSDAY. IT IS EXPECTED TO TRACK NORTHEAST AND PUSH OVER THE
ROCKIES. AS THIS OCCURS, PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN
ACROSS THE PLAINS. WINDS ARE EXPECTED TO INCREASE OUT OF THE SOUTH
15-20 MPH WITH GUSTS REACHING UP TO 25 MPH AND PUSHING 35 MPH IN
NORTHWEST IOWA. THIS WILL CONTINUE TO SUPPORT THE WARMING TREND AND
COULD EVEN LEAD TO AN ELEVATED FIRE RISK, ESPECIALLY IN WESTERN AND
NORTHWEST IOWA. THE GOOD THING THAT WILL BE WORKING FOR US, IS THAT
RELATIVE HUMIDITY VALUES WILL BE IN THE 30 TO 40% RANGE. AS THE
PRESSURE GRADIENT STRENGTHENS OUT WEST AND A STRENGTHENING 850MB
LLJ, MOISTURE WILL BE BROUGHT ACROSS PORTIONS OF NORTHERN NEBRASKA.
SHOWERS MAY DEVELOP ACROSS THE NOSE OF THE LLJ BUT SHOULD STAY WEST
OF CENTRAL IOWA. SO IN SUMMARY, FRIDAY IS SHAPING UP TO BE ANOTHER
WARM AND BREEZY DAY WITH HIGHS ONCE AGAIN IN THE 70S.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 101 PM CDT WED OCT 21 2026
BY SATURDAY MORNING A SOUTHERN STREAM 500 MB LOW/TROUGH WILL BE
CENTERED SOMEWHERE NEAR THE CALIFORNIA/ARIZONA BORDER. IT WILL
THEN DRIFT SLOWLY EAST NORTHEASTWARD TOWARD THE CENTRAL U.S.
OVER THE WEEKEND AND INTO EARLY NEXT WEEK. BY MONDAY EVENING IT
SHOULD BE LOCATED SOMEWHERE ROUGHLY AROUND NEBRASKA, BUT BY
THAT TIME A SECOND 500 MB CYCLONE WILL HAVE COME ASHORE OVER THE
NORTHWESTERN CONUS. AS THESE TWO SYSTEMS INTERACT WITH EACH
OTHER THE DETAILS OF THEIR EVOLUTION BECOME MORE UNCERTAIN, BUT
BY SATURDAY NIGHT THE SURFACE TROUGH DISCUSSED IN THE SHORT TERM
SECTION ABOVE SHOULD BE PUSHED ACROSS THE DAKOTAS AND LIE IN AN
ORIENTATION PARALLEL TO THE STEERING FLOW, ROUGHLY FROM THE
CENTRAL HIGH PLAINS NORTHEASTWARD NEAR THE IOWA/MINNESOTA BORDER
AND INTO THE UPPER GREAT LAKES. FRONTOGENETICAL FORCING
ASSOCIATED WITH THIS INCREASINGLY BAROCLINIC ZONE, BENEATH
MODEST BUT BROAD FORCING FOR ASCENT ALOFT, WILL SUPPORT
INCREASING RAIN POTENTIAL NEAR THE BOUNDARY AS WE PROGRESS
THROUGH THE WEEKEND. MOST OF THIS POTENTIAL WILL INITIALLY LIE
NORTH AND WEST OF OUR AREA, BUT POPS ARE INTRODUCED FOR OUR
NORTHWESTERN COUNTIES BEGINNING SATURDAY NIGHT AND CONTINUING
THROUGH SUNDAY NIGHT. THE BOUNDARY/SWATH OF RAIN WILL BE SLOW TO
PROGRESS ANY FARTHER INTO IOWA UNTIL THE MAIN SYSTEM/S MOVE
THROUGH SOMETIME BETWEEN MONDAY AND TUESDAY. GIVEN THIS OVERALL
SCENARIO, UNSEASONABLY WARM CONDITIONS IN PLACE LATE THIS WEEK
WILL CONTINUE THROUGH SATURDAY, WITH THE APPROACHING
TROUGH/FRONTAL ZONE/RAIN SWATH REMAINING NORTHWEST OF IOWA
DURING THAT TIME, THEN BE SHUNTED STEADILY SOUTHEASTWARD SUNDAY
AND MONDAY, WITH DAILY HIGHS LIKELY MORE IN THE 50S AND 60S BY
TUESDAY AND WEDNESDAY OF NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1044 PM CDT WED OCT 21 2026
MAIN AVIATION CHALLENGE REMAINS WHETHER FOG WILL FORM AND TO
WHAT EXTENT. WIDESPREAD FOG SEEMS QUITE UNLIKELY; HOWEVER,
PATCHY, SHALLOW FOG IN LOW LYING AREAS REMAINS POSSIBLE OVER
NORTHERN IOWA SO HAVE TRANSITIONED TO TEMPO GROUPS AT BOTH MCW
AND FOD. OTHERWISE, WINDS WILL BE LIGHT TO CALM OVERNIGHT AND
INCREASE TO BETWEEN 4 TO 9 KNOTS BY THURSDAY AFTERNOON AS VFR
CONDITIONS PREVAIL.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...TDR
LONG TERM...LEE
AVIATION...ANSORGE
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