672
FXUS63 KDMX 132005
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
305 PM CDT FRI MAR 13 2026
KEY MESSAGES
- LIGHT SNOW POSSIBLE ACROSS NORTHERN IOWA TONIGHT INTO EARLY
SATURDAY. SNOW AMOUNTS GENERALLY UNDER AN INCH.
- WINTER SYSTEM MOVES THROUGH LATE SATURDAY NIGHT THROUGH
SUNDAY, WITH STRONG WINDS ON SUNDAY LEADING TO POTENTIAL
BLIZZARD CONDITIONS. HIGHEST SNOWFALL ACCUMULATIONS EXPECTED
OVER NORTHERN AND NORTH CENTRAL IOWA. A BRIEF PERIOD OF
FREEZING RAIN POSSIBLE AS RAIN TRANSITIONS TO SNOW SUNDAY
MORNING.
- A FEW THUNDERSTORMS POSSIBLE CENTRAL AND SOUTH ON SATURDAY
MORNING. HAIL WOULD BE THE MAIN CONCERN WITH ANY STORMS.
- WIND GUSTS OF 45 TO 55 MPH ARE POSSIBLE DURING THE DAY ON
SUNDAY.
SHORT TERM /THROUGH MONDAY/
ISSUED AT 301 PM CDT FRI MAR 13 2026
THE STRONG WINDS FROM LAST NIGHT AND THIS MORNING GUSTED UP TO 69
MPH, BUT HAVE LESSENED CONSIDERABLY TODAY. WHILE MUCH LESS THAN LAST
NIGHT, BREEZY NORTHWESTERLY WINDS DO STILL CONTINUE TODAY, GENERALLY
AROUND 15 TO 20 MPH WITH GUSTS UP TO 35 MPH. AS PRESSURE GRADIENTS
WANE THIS AFTERNOON AND EVENING, WE'LL ALSO SEE WINDS GENERALLY
DECREASE THROUGH TONIGHT, BECOMING LIGHT BY EARLY TOMORROW MORNING.
A BRIEF PERIOD OF HIGH PRESSURE WILL MOVE THROUGH OVERNIGHT BEFORE
SURFACE LOW PRESSURE BUILDS FROM THE WEST AHEAD OF A PROMINENT
WINTER SYSTEM SLATED TO IMPACT THE MIDWEST THIS WEEKEND.
OUR FIRST SIGN OF ARRIVAL FOR THIS SYSTEM WILL ACTUALLY BE TONIGHT
INTO EARLY SATURDAY, AS A WING OF THETA-E ADVECTION LIFTS NORTHWARD
INTO THE STATE. MOISTURE AVAILABILITY ALOFT WILL BE PLENTIFUL
WITH THIS WING, BUT LACKING AT THE SURFACE, MEANING TOP-DOWN
SATURATION WILL NEED TO TAKE PLACE BEFORE SNOW REACHES THE
GROUND. THIS HAS BEEN TRENDING DRIER WITH RECENT GUIDANCE, BUT
HAVE MAINTAINED AT LEAST LIGHT SNOW ACCUMULATIONS (UNDER AN
INCH) ALONG THE IOWA/MINNESOTA BORDER.
THE MAIN SYNOPTIC WAVE WILL APPROACH THE AREA THROUGH THE DAY ON
SATURDAY, STREAMING WARMER AIR AND A HEALTHY PLUME OF MOISTURE UP
INTO THE STATE INTO THE EVENING AND OVERNIGHT HOURS. THIS WILL
RESULT IN A BROAD SWATH OF HEAVY SNOWFALL MAINLY OVER MINNESOTA AND
WISCONSIN, AND POTENTIALLY FAR NORTHERN IOWA SATURDAY NIGHT INTO
EARLY SUNDAY. THAT SAID, THE RECENT TREND IN GUIDANCE HAS BEEN
FARTHER NORTH WITH THIS INITIAL BAND OVERNIGHT SATURDAY INTO SUNDAY,
WITH MOST OF GUIDANCE KEEPING SNOW OUT OF IOWA THROUGH 12Z ON
SUNDAY. TO ACCOUNT FOR THIS DRIER TREND SATURDAY NIGHT, HAVE PUSHED
THE START TIME FOR THE WINTER STORM WATCH BACK TO 06Z ON SUNDAY,
WHICH MAY STILL BE TOO EARLY IF THE BAND DOESN'T WIGGLE BACK
SOUTHWARD.
WHILE THE INITIAL BAND OF SNOW IS TRENDING NORTH, THESE
SOLUTIONS ALSO RESULT IN MORE INSTABILITY BEING PULLED UP INTO IOWA
EARLY SUNDAY MORNING. DRY MID-LEVEL AIR MAY INHIBIT STORM
DEVELOPMENT, BUT A FEW RUMBLES OF THUNDER CAN'T BE RULED OUT AS THE
LOW PASSES OVERHEAD SUNDAY MORNING, ESPECIALLY ALONG THE WARM FRONT.
HAIL WOULD BE THE MAIN CONCERN WITH ANY STORMS, AND SEVERITY LOOKS
LOW GIVEN INSTABILITY VALUES GENERALLY UNDER 500 J/KG. THAT SAID,
THE COLORADO STATE UNIVERSITY MACHINE LEARNING SEVERE PROBABILITIES
ARE KEYING ON SOME HAIL PROBABILITIES OVER IOWA AND THE STORM
PREDICTION CENTER DOES HAVE AN OUTLOOK FOR GENERAL THUNDER AND
A MARGINAL RISK FOR SEVERE WEATHER IN FAR SOUTHEASTERN IOWA
EARLY SUNDAY, SO WILL WANT TO AT LEAST KEEP THE POTENTIAL FOR
STORMS IN MIND.
GIVEN THE GUIDANCE TODAY, WHAT LOOKS LIKE THE MAIN STORY OF THIS
SYSTEM WILL BE THE TROWAL DEVELOPMENT AND WRAP AROUND PRECIPITATION
OCCURRING BEHIND THE SURFACE LOW PASSAGE DURING THE DAY ON SUNDAY,
IN ADDITION TO VERY STRONG WINDS DEVELOPING BEHIND THE LOW. THE GFS
AND NAM ARE MOST BULLISH ON THIS WRAP AROUND SNOWFALL, SHOWING
ANYWHERE FROM 3 TO 6 INCHES ON AVERAGE, WITH EVEN HIGHER AMOUNTS
ALONG NORTHERN IOWA PUSHING 10"+ BY MONDAY MORNING. THESE TWO
SOLUTIONS ALSO SHOW THE SURFACE LOW DEEPENING OVERHEAD, WHILE OTHER
SOLUTIONS HAVE IT DEEPEN FARTHER EAST INSTEAD, WHICH RESULTS IN
HEAVIER SNOWFALL AMOUNTS OVER EASTERN IOWA AND LOWER AMOUNTS IN
CENTRAL IOWA, GENERALLY IN THE 0 TO 2" RANGE. THEREFORE, CONFIDENCE
IS LOW IN THE AMOUNT OF SNOW THAT WILL FALL ON SUNDAY BUT CONFIDENCE
IS HIGH FOR STRONG WINDS DEVELOPING WITH GUSTS OF 45 TO 55 MPH
POSSIBLE, SIMILAR TO THIS MORNING. ANY SNOW THAT DOES OCCUR ON
SUNDAY WITH THESE WINDS WILL LEAD TO BLIZZARD-LIKE CONDITIONS, AT
LEAST WHILE THE SNOW IS FALLING. THEREFORE, WHILE THERE IS A LOWER
LIKELIHOOD OF THE INITIAL HEAVY SNOW BAND IMPACTING NORTHERN IOWA
SATURDAY NIGHT INTO SUNDAY, AND UNCERTAINTY STILL EXISTS WITH TOTAL
SNOW AMOUNTS DURING THE DAY ON SUNDAY, THE WINTER STORM WATCH WILL
REMAIN IN PLACE FOR MUCH OF CENTRAL INTO NORTHERN IOWA FOR THE
POTENTIAL BLIZZARD CONDITIONS ON SUNDAY. EVEN IF WE DON'T GET SNOW,
WINDS WILL BE APPROACHING HIGH WIND CRITERIA OVER MUCH OF THE STATE
AS WELL, SO WIND HEADLINES WILL EVENTUALLY BE NEEDED. STRONG WINDS
WILL CONTINUE INTO MONDAY MORNING. DEPENDING ON THE AMOUNT OF
SNOW THAT FALLS ON SUNDAY, BLOWING SNOW COULD PERSIST INTO
EARLY MONDAY MORNING, IMPACTING THE MONDAY MORNING COMMUTE AS
WELL.
FINALLY, AS IF THERE WASN'T ENOUGH TO CONSIDER ALREADY WITH THIS
SYSTEM, WE ARE ALSO MONITORING POTENTIAL FOR SOME FREEZING RAIN
AND/OR ICE PELLETS AS THE COLD AIR INITIALLY ARRIVES ON SUNDAY
MORNING. THIS LIKELY WOULDN'T BE LONG LIVED, AS LIQUID PRECIPITATION
TRANSITIONS OVER TO A SNOWFALL WITH THE COLDER TEMPERATURES,
BUT A FEW HOURS OF FREEZING RAIN MAY STILL LEAD TO A LIGHT
GLAZING OF ICE BEFORE SNOW FALLS ON TOP OF IT. THIS THREAT LOOKS
MOST LIKELY OVER NORTHERN IOWA EARLY SUNDAY MORNING, BUT COULD
DEVELOP IN PORTIONS OF CENTRAL IOWA AS WELL.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
ISSUED AT 301 PM CDT FRI MAR 13 2026
WINDS WILL REMAIN BREEZY BUT STEADILY DIMINISH THROUGH MONDAY
AFTERNOON AND EVENING. TEMPERATURES WILL BE MUCH COOLER ON
MONDAY WITH HIGHS ONLY REACHING THE TEENS TO LOW 20S. THESE
COOLER TEMPERATURES THEN CONTINUE INTO INTO TUESDAY WITH ONE
MORE WEAKER SYSTEM BRINGING SNOW POTENTIAL TUESDAY NIGHT INTO
WEDNESDAY. BEYOND WEDNESDAY, RIDGING THEN BUILDS IN FROM THE
WEST, WARMING TEMPERATURES THROUGH THE END OF NEXT WEEK. THIS
SHOULD HELP TO MELT ANY SNOW ON THE GROUND, WITH THE RETURN OF
HIGHS IN THE 50S AND 60S POSSIBLE BY NEXT WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1239 PM CDT FRI MAR 13 2026
CONDITIONS WILL PREVAIL VFR THROUGH THE PERIOD AS GUSTY WINDS
FROM THE NORTHWEST CONTINUE TO DECREASE THROUGH THE AFTERNOON
INTO THIS EVENING. WHILE THE PROB30 FOR LIGHT SNOW REMAINS AT
FOD/MCW, THE CHANCES ARE DECREASING AND MAY NEED TO BE REMOVED
AT THESE TERMINALS WITH THE DRIER AIR UNDERCUTTING THE
PRECIPITATION FROM REACHING THE GROUND. AT ALO, CONFIDENCE WAS
SUFFICIENT TO REMOVE THE PROB30. OTHERWISE, WINDS WILL BECOME
FROM THE EAST BY SUNRISE SATURDAY AND INCREASE ABOVE 12 KNOTS BY
THE END OF THE PERIOD, PARTICULARLY WEST OF A MCW-TNU-TVK LINE.
DMX WATCHES/WARNINGS/ADVISORIES
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR IAZ004>007-015>017.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR IAZ023>028-033>039-044>050-057>062.
SHORT TERM...DODSON
LONG TERM...DODSON
AVIATION...ANSORGE
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