709
FXUS63 KDMX 201153
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
553 AM CST FRI FEB 20 2026
...UPDATED FOR THE 12Z AVIATION DISCUSSION...
KEY MESSAGES
- ACCUMULATING SNOW ENDING THIS MORNING. BLOWING SNOW MAY
PERSIST THROUGH THE MORNING.
- BELOW NORMAL TEMPERATURES THROUGH THE WEEKEND AND MOSTLY DRY.
UPDATE
ISSUED AT 420 AM CST FRI FEB 20 2026
SURFACE LOW PRESSURE CONTINUES TO DEEPEN AS IT LIFTS INTO SOUTHERN
WISCONSIN THIS MORNING. THIS HAS RESULTED IN AN INCREASING PRESSURE
GRADIENT WHAT IS NOW OVER 50 UBARS/KM OVER EASTERN IOWA. THIS IS
PRODUCING WIND GUSTS OF 30-40 MPH AND RESULTING IN BLOWING AND
DRIFTING OF SNOW. THE MAIN DEFORMATION ZONE IS NOW EXTENDING FROM
NORTHEAST IOWA INTO CENTRAL IOWA THROUGH THE BACKSIDE IS
BEGINNING TO ROTATE SOUTHEAST RAPIDLY OVER CENTRAL IOWA. THE
UPPER LEVEL PV ANOMALY WITH THIS SYSTEM HAS BEEN IMPRESSIVE WITH
THE 1.5 PV SURFACE REACHING DOWN TO NEAR 850 MB. THE ATTENDANT
UPPER LEVEL SHORT WAVE IS BEGINNING TO PASS TO THE EAST WITH THE
KINEMATIC FORCING DIMINISHING WITH MID- LEVEL DRYING AND
SUBSIDENCE BEGINNING TO MOVE IN FROM THE SOUTH. THE BULK OF THE
ACCUMULATING SNOWFALL WILL END BY 6 AM EXCEPT THE FAR
NORTHEAST. BLOWING SNOW WILL LINGER AFTER THAT TIME AND WILL
NEED TO EXTEND HEADLINES BEYOND 6 AM OVER PARTS OF THE AREA.
VERY LIGHT SNOW TO FLURRIES MAY LINGER OVER NORTHERN IOWA AS AS
SOME RESIDUAL MOISTURE WITHING THE FAVORED DENDRITIC GROWTH ZONE
ALONG WITH A FEW POCKETS OF WEAK VERTICAL ASCENT.
A FEW SYSTEMS MOVE THROUGH THIS WEEKEND WITH THE FIRST ARRIVING ON
SATURDAY THEN THE NEXT ON SUNDAY. BOTH SYSTEMS WILL BE MOISTURE
CHALLENGED, ESPECIALLY ON SUNDAY. PERHAPS A FEW FLURRIES REACH
SOUTHERN IOWA ON SATURDAY. TEMPERATURES WILL BE COOLER WITH THE NEW
SNOW PACK WITH HIGHS GENERALLY IN THE TEENS AND 20S THROUGH THE
WEEKEND AND OVERNIGHT LOWS IN THE SINGLE DIGITS AND TEENS.
DISCUSSION
ISSUED AT 219 PM CST THU FEB 19 2026
RADAR RETURNS ARE INCREASING OVER SOUTHERN IOWA SHOWING OUR FIRST
INDICATIONS OF THE APPROACHING LOW PRESSURE SYSTEM TODAY, WHICH WILL
EVENTUALLY BRING A BAND OF MODERATE TO HEAVY SNOW TO THE STATE THIS
AFTERNOON THROUGH THE EVENING. DRY SUB-CLOUD AIR IS LIMITING MOST OF
THIS PRECIPITATION FROM REACHING THE GROUND, BUT RAIN AND/OR
FROZEN PRECIPITATION HAS STARTED BEING REPORTED UNDER SOME OF
THE BETTER RETURNS. INTERESTINGLY ENOUGH, EVEN SOME LIGHTNING
HAS BEEN DETECTED IN TAYLOR AND ADAMS COUNTIES. MOST OF THIS
PRECIPITATION WILL BE LIGHT INITIALLY AS IT WORKS THROUGH THE
DRY AIR, BUT AREAS WITH MORE CONVECTIVE ELEMENTS COULD SEE MORE
SUBSTANTIAL SHOWERS.
AS WE CONTINUE THROUGH THE AFTERNOON, THE PARENT WAVE AND SURFACE
LOW WILL CONTINUE TO LIFT NEARER TO THE STATE, BRINGING BETTER
FORCING IN THE FORM OF MID-LEVEL WARM AIR ADVECTION AND
FRONTOGENESIS. THIS WILL DRASTICALLY INCREASE LIFT THROUGH THE
SATURATED MID-LEVELS, LEADING TO INCREASED HYDROMETEOR PRODUCTION
AND BETTER TOP-DOWN SATURATION TO THE SURFACE. DESPITE THE DRY LOW
LEVELS, THE EXPECTATION IS FOR THIS TOP-DOWN SATURATION TO HAPPEN
FAIRLY QUICKLY WITH 20 TO 30 MICROBARS OF LIFT THROUGH THE MID-
LEVELS AND DENDRITIC GROWTH ZONE. AS THIS SATURATION OCCURS AND
COLDER AIR MOVES IN, TEMPERATURES WILL BEGIN TO WETBULB DOWN TO AND
BELOW 0C, QUICKLY TRANSITIONING ANY RAIN OVER TO SNOW.
MODERATE TO HEAVY SNOW IS EXPECTED BENEATH THE AREAS OF STRONGEST
LIFT, RESULTING IN PERIODS OF INCH PER HOUR SNOWFALL RATES. THESE
RATES WILL QUICKLY COOL OFF ANY WARMER AIR REMAINING AT THE SURFACE
AND OVERCOME WARMER GROUND TEMPERATURES TO ALLOW FOR ACCUMULATING
SNOW. FORTUNATELY, THE HEAVIEST BAND SEEMS SOMEWHAT PROGRESSIVE AS
IT LIFTS NORTHWARD, WHICH SHOULD HELP REDUCE RESIDENCE TIME UNDER
THE HEAVIEST RATES AND KEEP SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR MOST OF CENTRAL IOWA. HOWEVER, THERE WILL LIKELY BE AN
AREA WHERE RESIDENCE TIME UNDER THE BAND IS INCREASED DUE TO THE
SYSTEM PIVOTING AND BAND WRAPPING AROUND THE LOW AS IT TRANSLATES
EASTWARD. THIS INCREASED RESIDENCE TIME WILL LEAD TO A SOUTHWEST TO
NORTHEAST ORIENTED SWATH OF LOCALLY HIGHER AMOUNTS OF 3 TO 6+ INCHES
OF SNOWFALL. THE FORECAST AND GUIDANCE HAS NARROWED IN ON A LIKELY
LOCATION FOR THESE HIGHER AMOUNTS, RUNNING ROUGHLY FROM OMAHA
THROUGH AMES AND UP INTO WATERLOO. HOWEVER, ANY SMALL SHIFT IN THE
STORM TRACK COULD SHIFT THESE HIGHER AMOUNTS SLIGHTLY FARTHER NORTH
OR SOUTH WITH A SHARP CUT OFF ON EITHER SIDE. GIVEN THE EXPECTATION
FOR A BAND OF HEAVIER SNOWFALL RATES AND ACCUMULATIONS NEARING 6
INCHES OR MORE, HAVE UPGRADED THE WINTER WEATHER ADVISORY TO A
WINTER STORM WARNING THROUGH THE EXPECTED AREAS. IT IS WORTH NOTING
THAT, GIVEN THE NATURE OF THE BAND, THERE WILL LIKELY BE SOME AREAS
IN THE WARNING THAT ONLY SEE A COUPLE OF INCHES SNOW. HOWEVER, THE
POTENTIAL FOR HIGHER END SNOWFALL UNDER THE BAND, RESULTING IN
IMPACTS TO TRAVEL BOTH FROM ACCUMULATING SNOW AND FROM LOW
VISIBILITY IN THE HIGHER RATES AND BREEZY CONDITIONS, IS WHAT
WARRANTED THE BROADER WARNING AREA.
WHILE MOSTLY SNOW LOOKS TO FALL OVER CENTRAL INTO NORTHERN IOWA,
SOUTHERN AND SOUTHEASTERN IOWA COULD BE LOOKING AT A SLIGHTLY
DIFFERENT SUBSET OF CONDITIONS. THESE LOCATIONS WILL HAVE SLIGHTLY
WARMER AIR AND DRIER MID-LEVELS, WHICH INTRODUCES SOME OTHER HAZARDS
BOTH PRIOR TO AND AFTER THE COLD AIR ARRIVES. FIRST, AS THE WARM AIR
ADVECTION WING STARTS TO SATURATE THROUGH THE LAYER THIS AFTERNOON,
WE MAY SEE A PERIOD OF LIGHT RAIN/SHOWERS AND POTENTIALLY MORE
RUMBLES OF THUNDER GIVEN THE SMALL AMOUNTS OF INSTABILITY (~100 TO
200 J/KG OF MUCAPE) STILL LIFTING OVER THE SOUTHERN PORTIONS OF THE
STATE. THEN, AS THE COLDER LOW LEVEL AIR BEGINS TO FILL IN BEHIND
THE LOW, THE COLUMN WILL BEGIN TO COOL BELOW FREEZING. AS THIS
OCCURS, SOME SOUNDINGS ALSO SHOW A LOSS OF SATURATION THROUGH THE
DENDRITIC GROWTH ZONE. NO ICE INTRODUCTION IMPLIES A HIGHER
LIKELIHOOD FOR SUPERCOOLED DROPLETS MIXED IN WITH THE ICE CRYSTALS,
WHICH COULD LEAD TO SOME FREEZING RAIN OR FREEZING DRIZZLE TONIGHT.
FORTUNATELY, THIS IS WHERE THE WARMEST SURFACE TEMPERATURES RESIDE,
WHICH MAY INITIALLY INHIBIT FREEZING. THIS LOSS OF ICE INTRODUCTION
ISN'T A PERSISTENT SIGNAL, EITHER, WITH SATURATING DIPPING IN AND
OUT OF THE DGZ. THEREFORE, THIS IS A LOWER CONFIDENCE SCENARIO, BUT
WILL NEED TO BE WATCHED CLOSELY THIS EVENING AS ROADS COULD BECOME
SLICK AFTER THEY DROP BELOW FREEZING.
PRECIPITATION GENERALLY WRAPS UP EARLY FRIDAY MORNING, BUT
TRAVEL CONDITIONS MAY REMAIN DETERIORATED INTO THE MORNING
COMMUTE AS PLOWS WORK TO GET ROADS CLEARED, ESPECIALLY IN THE
AREAS WITH THE HEAVIEST SNOWFALL. TEMPERATURES DON'T WARM ABOVE
FREEZING ON FRIDAY, BUT CLEARING SKIES IN THE AFTERNOON SHOULD
AT LEAST HELP WITH SNOW REMOVAL ON FRIDAY. WINDS ALSO REMAIN
BREEZY THROUGH FRIDAY MORNING, WHICH COULD LEAD TO SOME DRIFTING
OF FRESH SNOW, BUT BLOWING SNOW SHOULDN'T BE A WIDESPREAD
ISSUE. CONDITIONS THEN REMAIN MUCH COOLER AND DRY THROUGH THE
WEEKEND WITH LIGHT TO POTENTIALLY BREEZY WINDS BY SUNDAY.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 549 AM CST FRI FEB 20 2026
SNOW WILL BE ENDING FROM SOUTHWEST TO NORTHEAST EARLY IN THE
PERIOD. BLOWING SNOW MAY PERSIST A BIT LONGER. HAVE SLOWED THE
PROGRESSION OF THE IFR TO MVFR STRATUS WITH A LARGE AREA
REMAINING UPSTREAM OF SITES. SOME OF THIS STRATUS EXTENDS ALL
THE WAY TO MANITOBA WITH THE STEERING FLOW SUGGESTING IT WILL
CONTINUE TO MOVE SOUTH/SOUTHEAST. THAT MAY RESULT IN A MORE
PROLONGED PERIOD OF STRATUS, ESPECIALLY OVER NORTHERN IOWA
THOUGH THERE ARE POCKETS OF VFR. GUSTY NORTHWEST WIND WILL
GRADUALLY DIMINISH TODAY AND WILL BE LESS THAN 10 KTS TONIGHT.
DMX WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ017-
025-061-062-073-074.
WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
IAZ023-024-033-034-071-072-081-082.
WINTER STORM WARNING UNTIL 9 AM CST THIS MORNING FOR
IAZ026>028-036>039-048>050-060.
WINTER STORM WARNING UNTIL 6 AM CST EARLY THIS MORNING FOR
IAZ035-044>047-057>059-070.
UPDATE...DONAVON
DISCUSSION...DODSON
AVIATION...DONAVON
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