361
FXUS63 KDMX 112307
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
607 PM CDT WED MAR 11 2026
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- STRONG AND GUSTY WINDS AND DRY CONDITIONS ARE FORECAST
THURSDAY, ESPECIALLY IN SOUTHWESTERN IOWA WHERE A RED FLAG
WARNING HAS BEEN ISSUED.
- EVEN STRONGER WINDS ARE FORECAST THURSDAY NIGHT, ESPECIALLY
ACROSS NORTHERN IOWA WHERE GUSTS TO AROUND 60 MPH ARE POSSIBLE
AND A HIGH WIND WATCH HAS BEEN ISSUED.
- CONFIDENCE IN A POTENTIALLY SIGNIFICANT WINTER STORM THIS
WEEKEND IS STEADILY INCREASING. HOWEVER, THE TRACK OF THE
SYSTEM AND ANY RESULTING HEAVY SNOWFALL IS STILL COMING INTO
FOCUS. AT THIS TIME THE MOST LIKELY AREA FOR MOST SIGNIFICANT
IMPACTS IS ACROSS PARTS OF MINNESOTA, WISCONSIN, AND NORTHERN
IOWA, BUT ANY CHANGES TO THE FORECAST TRACK WOULD
SIGNIFICANTLY IMPACT THIS POTENTIAL. STAY TUNED TO FORECAST
UPDATES IN THE COMING DAYS.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 230 PM CDT WED MAR 11 2026
A BAND OF LIGHT SNOW, MIXED WITH RAIN IN SOME AREAS, MOVED THROUGH
CENTRAL IOWA THIS MORNING AND IS NOW EXITING OUR EASTERN AND
SOUTHEASTERN COUNTIES. ANY ADDITIONAL SNOW ACCUMULATION OR IMPACT
WILL BE NEGLIGIBLE. MEANWHILE, NORTH NORTHWEST BREEZES AND LINGERING
CLOUD COVER ARE KEEPING TEMPERATURES NOTABLY COOLER TODAY THAN ON
PREVIOUS DAYS, THOUGH RAPID CLEARING WILL ALLOW TEMPERATURES TO
REBOUND TO SOME EXTENT THIS AFTERNOON AND MELT MUCH OF THE SNOW
THAT FELL THIS MORNING. A SURFACE RIDGE WILL THEN SLIDE ACROSS
THE HIGH PLAINS AND IOWA TONIGHT, RESULTING IN DIMINISHING AND
BACKING WINDS AND MOSTLY CLEAR SKIES OVERNIGHT. A WEAK MID-LEVEL
IMPULSE WILL BE TRAVELING OVER MINNESOTA, WISCONSIN, AND
NORTHERN IOWA OVERNIGHT AND MAY GENERATE SOME CLOUDS THERE. SOME
MODELS ARE SPITTING OUT SMALL/LIGHT QPF BULLSEYES IN AN ATTEMPT
TO GENERATE SPRINKLES/FLURRIES, HOWEVER, FORECAST SOUNDINGS
ILLUSTRATE CONSIDERABLE DRY AIR BELOW ANY CLOUD LAYER AND A DRY
FORECAST HAS BEEN MAINTAINED ACCORDINGLY.
ON THURSDAY NEUTRAL NORTHWESTERLY 500 MB FLOW WILL BE IN PLACE
OVER IOWA, WHILE AN INTENSE AND ELONGATED TROUGH STRETCHES FROM
FAR SOUTHWESTERN CANADA OVER TO NORTH DAKOTA BY THE AFTERNOON. A
SURFACE TROUGH WILL DEEPEN RAPIDLY ACROSS THE NORTHERN HIGH
PLAINS IN RESPONSE TO THIS APPROACHING SYSTEM, EVEN AS THE
AFOREMENTIONED SURFACE RIDGE MOVES AWAY TO OUR SOUTHEAST OVER
THE OHIO RIVER VALLEY. BETWEEN THESE TWO SYSTEMS A TIGHT
PRESSURE GRADIENT WILL PROMOTE STRENGTHENING SOUTH SOUTHWEST
WINDS ACROSS OUR SERVICE AREA, AS WELL AS LOW-LEVEL WARM AIR
ADVECTION THAT WILL SEND TEMPERATURES RISING INTO THE 50S TO
LOWER 60S ON THURSDAY AFTERNOON. MOST MODEL OUTPUT SHOWS WINDS
NEARING ADVISORY CRITERIA, MOST PROMINENTLY THE HRRR WHICH (ON
THE 12Z RUN) DEPICTS A LARGE AREA OF 40-45 MPH GUSTS CROSSING
OUR AREA IN THE AFTERNOON. HOWEVER, THERE ARE SOME MITIGATING
FACTORS TO CONSIDER. ONE IS THAT WITH THE WIND DIRECTION AND
WARM AIR ADVECTION REGIME, DOWNWARD MOMENTUM TRANSPORT WILL NOT
ENHANCE THE MIXING AND CLIMATOLOGICALLY ADVISORY CRITERIA IS
MORE DIFFICULT TO REACH IN THESE SITUATIONS. ANOTHER IS THAT
MID- LEVEL CLOUDS WILL GRADUALLY THICKEN DURING THE DAY AHEAD OF
THE SYSTEM APPROACHING FROM THE NORTHWEST, WHICH WILL ALSO
SUPPRESS TURBULENT MIXING TO SOME EXTENT. GIVEN THESE DETRACTING
FACTORS AND THE MARGINAL NATURE OF THE FORECAST VALUES RELATIVE
TO ADVISORY CRITERIA, A WIND ADVISORY HAS NOT BEEN ISSUED AND
WE WILL CONTINUE TO MONITOR SHORT-TERM FORECAST TRENDS IN CASE
ONE BECOMES WARRANTED OVERNIGHT. THE STRONG WINDS AND DRY
CONDITIONS WILL ALSO PROMOTE A CRITICAL FIRE WEATHER DANGER IN
OUR SOUTHWESTERN COUNTIES ON THURSDAY, AND A RED FLAG WARNING
HAS BEEN ISSUED FOR THAT AREA. THESE CONCERNS ARE DISCUSSED IN
MORE DETAIL IN THE FIRE WEATHER SECTION BELOW.
ON THURSDAY NIGHT THE INTENSE 500 MB TROUGH WILL DEEPEN FURTHER
AND DIG SOUTHEASTWARD ACROSS MINNESOTA AND WISCONSIN, SCRAPING
NORTHERN AND NORTHEASTERN IOWA AS IT PASSES. THIS SYSTEM WILL
PUSH A STRONG SURFACE TROUGH SOUTHEASTWARD THROUGH IOWA ON
THURSDAY NIGHT, CAUSING WINDS TO TURN FROM SOUTHWEST TO WEST
NORTHWEST AND STRENGTHEN EVEN FURTHER OVERNIGHT. THE SURFACE
PRESSURE GRADIENT IN OUR AREA WILL REMAIN FAIRLY TIGHT BUT
LOOSEN A LITTLE THROUGH THE NIGHT, HOWEVER, BEHIND THE SURFACE
TROUGH THERE WILL BE SUBSTANTIAL PRESSURE RISES AS WELL AS
MULTIPLE HOURS OF STRONG LOW-LEVEL COLD AIR ADVECTION. WITH THE
STRONGEST 925 MB WINDS AND STEEPEST PRESSURE RISES OCCURRING
OVER NORTHERN IOWA, CLOSER TO THE PARENT SYSTEM, THE STRONGEST
SURFACE WINDS AND GUSTS ARE ALSO EXPECTED IN THAT AREA WITH ONLY
A GRADUAL DIMINISHMENT FARTHER SOUTH. THE ONLY QUESTION IS JUST
HOW STRONG THE WINDS WILL GET, AND HOW FAR SOUTH. IT IS A
CLASSIC SET-UP FOR A HIGH WIND EVENT, WITH THE ONLY MITIGATING
FACTOR BEING TIME OF DAY WHICH WILL LIMIT MIXING DEPTH. HOWEVER,
EVEN THE NAM WHICH HAS THE SHALLOWEST MIXED LAYER THURSDAY NIGHT
STILL SHOWS WINDS OF 42-48 KT AT THE TOP OF THE MIXED LAYER IN
OUR NORTHERN COUNTIES, WHICH IS NEAR WARNING CRITERIA. SEVERAL
OTHER MODELS, INCLUDING THE GFS WHICH DEPICTS TOP OF THE MIXED
LAYER WINDS OF 60-70 KT ACROSS OUR NORTH, AND THE HRRR WHICH
(ON THE 12Z RUN) DEPICTS WIDESPREAD 50-55 KT SURFACE GUSTS IN
THE NORTH. IN LIGHT OF THE HIGH CONFIDENCE IN SYNOPTIC
CONDITIONS AND THE POTENTIAL FOR CRITERIA TO BE SIGNIFICANTLY
EXCEEDED, HAVE ISSUED A HIGH WIND WATCH FOR AREAS ALONG AND
NORTH OF HIGHWAY 30 THURSDAY NIGHT. IT IS QUITE POSSIBLE THIS
WILL NEED TO BE UPGRADED TO A WARNING, AND PERHAPS EXPANDED
SOUTHWARD OR WITH AN ADVISORY ISSUED TO THE SOUTH, AT SOME
POINT TONIGHT OR TOMORROW.
STRONG AND GUSTY WINDS WILL PERSIST INTO FRIDAY MORNING, THEN
RAPIDLY DIMINISH LATER IN THE DAY AS A HIGH PRESSURE RIDGE
BUILDS IN QUICKLY FROM THE NORTHWEST DURING THE AFTERNOON. THIS
WILL PROVIDE A BRIEF WINDOW OF QUIETER WEATHER FRIDAY AFTERNOON
AND EVENING, AND WHILE TEMPERATURES WILL BE COOLER BEHIND THE
OVERNIGHT FRONT AND WITH THE HIGH BUILDING IN, SUNSHINE AND
DIMINISHING WINDS SHOULD STILL ALLOW TEMPERATURES TO RISE INTO
THE 40S ACROSS MOST OF THE FORECAST AREA. FROM FRIDAY NIGHT
THROUGH SATURDAY, THE FIRST STORM SYSTEM WILL BE DEPARTING FAR
TO OUR EAST WHILE YET ANOTHER 500 MB TROUGH DIGS QUICKLY ACROSS
THE NORTHERN U.S. ROCKIES. AS A RESULT, THE STEERING FLOW OVER
IOWA WILL BACK FROM NORTHWESTERLY TO WEST SOUTHWESTERLY DURING
THIS TIME, AND A BAND OF ISENTROPIC LIFT AND WARM AIR ADVECTION
ALOFT WILL SET UP FROM AROUND SOUTH DAKOTA ACROSS PARTS OF
MINNESOTA AND IOWA. AS THIS SWATH GRADUALLY DEVELOPS AND THE
LIFT WITHIN IT GRADUALLY INCREASES, LIGHT PRECIPITATION WILL
BECOME STEADILY MORE LIKELY IN THE PERIOD FROM AROUND FRIDAY
EVENING TO SATURDAY EVENING, AND THERMAL PROFILES GENERALLY
SUPPORT SNOW AS THE MOST LIKELY PRECIPITATION TYPE. HOWEVER,
THERE ARE TWO MITIGATING FACTORS TO CONSIDER. THE FIRST IS THAT
INITIALLY, THE AFOREMENTIONED SURFACE HIGH PRESSURE AREA
BUILDING INTO THE REGION ON FRIDAY WILL REMAIN IN PLACE AND ANY
LIGHT PRECIPITATION GENERATED BY THE RELATIVELY WEAKER FORCING
IS LESS LIKELY TO REACH THE SURFACE OR ACCUMULATE, THUS ONLY
20-30% CHANCES ARE CARRIED FRIDAY NIGHT INTO SATURDAY MORNING.
THE SECOND FACTOR IS THAT EVEN BY SATURDAY AFTERNOON AND EVENING
AS THE COLUMN BECOMES MORE SATURATED AND FORCING FOR ASCENT
CONTINUES TO INCREASE, THERE ARE DISCREPANCIES AMONG MODEL
SOLUTIONS AS TO HOW FAR NORTH THE SWATH OF DEVELOPING
PRECIPITATION WILL BE BY THAT TIME. THEREFORE, WHILE 30-40%
CHANCES ARE CARRIED IN OUR NORTHERN COUNTIES LATER SATURDAY, OUR
SOUTHERN COUNTIES ARE DRY AT THIS TIME PENDING ADDITIONAL
ANALYSIS IN THE COMING DAYS.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 230 PM CDT WED MAR 11 2026
A SIGNIFICANT WINTER STORM IS POSSIBLE ACROSS PORTIONS OF THE
UPPER MIDWEST BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT. AS
MENTIONED IN THE SHORT TERM DISCUSSION ABOVE, A 500 MB TROUGH
WILL DIG OVER THE NORTHERN U.S. ROCKIES ON SATURDAY.
SUBSEQUENTLY, IT WILL FURTHER INTENSIFY AND DIG SOUTHEASTWARD
OVER THE LATTER HALF OF THE WEEKEND, BECOMING NEARLY POSITIVELY
TILTED NEAR THE UPPER MISSISSIPPI RIVER VALLEY BY SUNDAY NIGHT.
A STRONG SURFACE CYCLONE WILL DEVELOP RAPIDLY IN RESPONSE TO THE
APPROACHING MID-LEVEL SYSTEM, INITIALLY NEAR THE KANSAS/COLORADO
BORDER SATURDAY EVENING AND EVENTUALLY TRACKING SOMEWHERE OVER
MISSOURI/SOUTHEASTERN IOWA/ILLINOIS AROUND SUNDAY MORNING OR SO.
THE SWATH OF DEVELOPING SNOWFALL DISCUSSED IN THE SHORT TERM
SECTION ABOVE WILL INITIALLY BE MOST LIKELY OVER OUR NORTHERN
AND NORTHEASTERN COUNTIES LATE SATURDAY, THEN PIVOT AND SWEEP
SOUTHEASTWARD LATER SATURDAY NIGHT AND SUNDAY. THERE IS HIGH
CONFIDENCE IN PRECIPITATION DURING THIS TIME AND POPS HAVE BEEN
INCREASED TO 70-80% ACROSS NEARLY OUR ENTIRE FORECAST AREA.
ALSO, CONFIDENCE CONTINUES TO INCREASE THAT ON THE NORTHERN
PERIPHERY OF THE DEVELOPING CYCLONE, WHERE THE INITIAL SWATH OF
SNOW WILL BEGIN EARLIER AND WHERE COLDER TEMPERATURES WILL ALLOW
FOR MORE SNOW TO FALL AS THE SYSTEM PASSES, A SIGNIFICANT WINTER
STORM MAY UNFOLD WITH HEAVY SNOW AND STRONG WINDS EXPECTED.
HOWEVER, WHERE CONFIDENCE HAS NOT INCREASED TODAY IS IN THE
TRACK OF THE LOW AND ASSOCIATED TEMPERATURE FIELDS, WHICH WILL
HAVE CRITICAL IMPLICATIONS FOR FORECAST SNOWFALL AMOUNTS AND
IMPACTS. WITH THE SURFACE LOW TRACKING NEAR OR OVER SOUTHEASTERN
IOWA, MUCH OF THE PRECIPITATION ACROSS THE SOUTHERN HALF OR SO
OF OUR AREA MAY INITIALLY FALL AS RAIN, LIMITING SNOW
ACCUMULATION POTENTIAL, WHILE IN NORTHERN IOWA OR ESPECIALLY
MINNESOTA AND WISCONSIN HEAVIER AND MORE PROLONGED SNOWFALL IS
EXPECTED. AT THIS TIME OUR NORTHERN AND NORTHEASTERN COUNTIES
APPEAR MORE LIKELY TO FALL INTO THE LATTER CATEGORY THAN THE
FORMER, HOWEVER, GIVEN THE DEGREE OF MODEL VARIABILITY IN
RESOLVING THE TRACK OF THE SYSTEM AND SUB-FREEZING PROFILES AT
THE CURRENT RANGE OF ABOUT 4 DAYS, NO WATCHES HAVE AS YET BEEN
ISSUED IN IOWA FOR THIS SYSTEM. WE WILL BE CLOSELY MONITORING IT
IN THE COMING DAYS, AND ANYONE PLANNING TRAVEL AROUND OR INTO
CENTRAL OR NORTHERN IOWA AND NEIGHBORING STATES SHOULD WATCH FOR
FORECAST UPDATES AND POSSIBLE WATCHES OR WARNINGS IN THE COMING
DAYS.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 607 PM CDT WED MAR 11 2026
WHILE TAFS SHOW PREVAILING VFR CONDITIONS THROUGH THE PERIOD,
MONITORING SHOWERY WINTRY PRECIPITATION MOVING INTO NORTHWESTERN
IOWA EARLY THIS EVENING. GUIDANCE IS NOT HANDLING THIS WELL DUE
TO DRY AIR SO HAVE NOT INTRODUCED PROB30 AT FOD. OUTSIDE OF THE
EARLY PERIOD CONCERN, CONFIDENCE IS HIGH IN VFR CONDITIONS THE
REMAINDER OF THE TIME. BREEZY WINDS FROM THE NORTHWEST WILL
BECOME LIGHTER AS THE SUN SETS, BUT WILL BECOME FROM THE SOUTH
AND SOUTHWEST BY THURSDAY MORNING INCREASING TO 20 TO 30 KNOTS
AND GUSTS OF 35 TO 40 KNOTS INTO THURSDAY AFTERNOON.
DMX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING
FOR IAZ004>007-015>017-023>028-033>039-044>050.
RED FLAG WARNING FROM NOON TO 9 PM CDT THURSDAY FOR IAZ044-045-
057-058-070-071-081-082-092-093.
SHORT TERM...LEE
LONG TERM...LEE
AVIATION...ANSORGE
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