477
FXUS63 KDMX 200007
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
607 PM CST THU FEB 19 2026
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- BAND OF MODERATE TO HEAVY SNOWFALL PASSING THROUGH CENTRAL AND
NORTH CENTRAL IOWA THIS AFTERNOON AND EVENING. SNOWFALL
AMOUNTS OF 6 INCHES OR MORE ARE POSSIBLE WITHIN THE HEAVIEST
BAND.
- FEW SHOWERS AND RUMBLES OF THUNDER IN SOUTHERN AND
SOUTHEASTERN IOWA THIS AFTERNOON AND EVENING. RAIN MAY
TRANSITION TO A FREEZING DRIZZLE OR SNOW OVERNIGHT.
- COLD AND DRY FRIDAY THROUGH THE WEEKEND.
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 /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 607 PM CST THU FEB 19 2026
A WINTRY MIX HAS EXPANDED ACROSS MUCH OF IOWA THIS EVENING.
PRECIPITATION TYPE VARIES ACROSS THE AREA FROM SNOW WEST OF I-35
TO A RAIN/SNOW/ICE PELLET MIX EAST OF I-35. PARTS OF SOUTHERN
IOWA HAVE SEEN MORE SLEET ALONG WITH THUNDER. A TRANSITION TO
ALL SNOW IS EXPECTED OVER THE NEXT FEW HOURS. MVFR TO IFR
CEILINGS ARE IN PLACE ACROSS MOST SITES. AS THE HEAVIER SNOW
BAND SETS UP OVERNIGHT EXPECT BOTH CEILINGS AND VISIBILITY TO
FALL TO IFR AND PERHAPS REACH LIFR IN THE HEAVIEST PORTION OF
THE BAND FROM AROUND 03-08Z. WHERE THIS NARROW BAND SETS UP IS
UNCERTAIN, BUT MOSTLY LIKELY IMPACTED SITES WOULD BE KDSM/KALO.
THIS WILL BE FINE TUNED THROUGH THE EVENING. SNOW TAPERS OFF
THROUGH THE EARLY MORNING HOURS ON FRIDAY WITH IMPROVEMENT BACK
TO VFR AROUND OR AFTER 18Z.
DMX WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 6 AM CST FRIDAY FOR IAZ017-025-
061-062-073-074.
WINTER WEATHER ADVISORY UNTIL 6 AM CST FRIDAY FOR IAZ023-024-
033-034-071-072-081-082.
WINTER STORM WARNING UNTIL 6 AM CST FRIDAY FOR IAZ026>028-
036>039-048>050-060.
WINTER STORM WARNING UNTIL 6 AM CST FRIDAY FOR IAZ035-044>047-
057>059-070.
DISCUSSION...DODSON
AVIATION...HAGENHOFF
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