806
FXUS63 KDMX 180530
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1130 PM CST TUE FEB 17 2026
...UPDATED FOR THE 06Z AVIATION DISCUSSION...
KEY MESSAGES
- LINGERING BREEZY CONDITIONS INTO THE EARLY EVENING.
- MARGINAL RISK FOR SEVERE STORMS OVER WESTERN IOWA TONIGHT.
- GUSTY CONDITIONS, ESPECIALLY NORTH, ALONG WITH CRITICAL FIRE
WEATHER CONDITIONS AREA-WIDE WEDNESDAY, LEADING TO WIND AND
FIRE WEATHER HEADLINES.
- RAIN/SNOW POTENTIAL THURSDAY INTO FRIDAY MORNING.
- INCREASING WINDS AND FALLING TEMPERATURES THURSDAY NIGHT INTO
FRIDAY WITH COOLER, MORE SEASONAL, TEMPERATURES FRIDAY INTO
THE WEEKEND.
DISCUSSION
ISSUED AT 307 PM CST TUE FEB 17 2026
WARM AND BREEZY CONDITIONS HAVE MATERIALIZED LARGELY AS FORECAST
ACROSS IOWA THIS AFTERNOON, WITH TEMPERATURES ACROSS THE STATE IN
THE UPPER 50S TO THE NORTH AND IN THE LOW 60S TO THE SOUTH, AS UPPER
LEVEL CLOUDS MAINLY ACROSS THE SOUTH AND EAST PER SATELLITE IMAGERY
HAVE PROVEN TO HINDER THIS WARMING VERY LITTLE. THE WARM AIR
ADVECTION LARGELY DRIVING THIS WARMTH IS AHEAD OF A LARGE SURFACE
LOW PRESSURE SYSTEM THAT IS CURRENTLY CENTERED OVER NEBRASKA/SOUTH
DAKOTA, WITH THIS ADVECTION AND INCREASED PRESSURE GRADIENT OVERHEAD
LEADING TO WINDY CONDITIONS ACROSS IOWA. WINDS HAVE INCREASED OUT OF
THE SOUTHEAST WITH GUSTS GENERALLY AROUND 30-35 MPH, WITH ISOLATED
VALUES UP TO 40 MPH AND EVEN A FEW ISOLATED GUSTS UP TO 45 MPH AT
CLARION AND DES MOINES. WINDS SHOULD REMAIN BELOW CRITERIA BUT WILL
REMAIN BREEZY UNTIL THIS EVENING, BEFORE LIGHTENING SLIGHTLY BUT
STILL BREEZY. ATTENTION THEN TURNS TO THE EASTWARD TRACKING COLD
FRONT, WHICH FROM RADAR ANALYSIS IS CURRENTLY OVER NEBRASKA. THE
EXPECTATION IS THAT THIS FRONT WILL ARRIVE INTO WESTERN IOWA AFTER
SUNSET THIS EVENING, WITH SHOWERS AND POSSIBLE THUNDERSTORMS MOVING
INTO THE FORECAST AREA LATER TONIGHT. STEEP LAPSE RATES AROUND 8
C/KM, ALONG WITH MUCAPE VALUES OF AT LEAST 100-200+ J/KG SETTING UP
AHEAD OF THE BOUNDARY SHOULD PROVE SUFFICIENT FOR AT LEAST SOME
STORM PRODUCTION, WITH THE MAIN HAZARD IF ANY LOOKING TO BE GUSTY
WINDS. HRRR RUNS THROUGH THE DAY HAVE GENERALLY BEEN HINGING ON
STORM POTENTIALLY PRODUCING SUB-SEVERE GUSTS AT LEAST OVER WESTERN
IOWA DURING THIS TIME, WHICH HAS BEEN CONSISTENT THROUGH THE DAY.
SPC HAS INTRODUCED A MARGINAL RISK OVER WESTERN IOWA AS A RESULT OF
THIS POTENTIAL, HIGHLIGHTING THE RISK FOR A FEW SEVERE STORMS.
ANY STORMS THAT DO OCCUR ARE EXPECTED TO EXIT EASTWARD OUT OF THE
FORECAST AREA EARLY WEDNESDAY MORNING, THOUGH CONDITIONS WILL REMAIN
ON THE BREEZY SIDE BUT SHIFTED OUT OF THE WEST AS THE SURFACE LOW
LIFTS SLOWLY NORTHEAST ACROSS THE UPPER MIDWEST, TIGHTENING THE
PRESSURE GRADIENT OVERHEAD, BUT ESPECIALLY OVER NORTHERN IOWA.
FOLLOWING SUNRISE, WINDS WILL INCREASE EVEN FURTHER, WHICH MODEL
SOUNDINGS INDICATING VERY DEEP AND EFFICIENT MIXING GIVEN THE
INTRUSION OF DRY AIR AND CLEARING SKIES. WINDS AT THE TOP OF THE
MIXED LAYER OVER 40-45+ KNOTS ARE INDICATED AT THE TOP OF THE LAYER,
ESPECIALLY IN NORTHERN IOWA, WHICH HAS INCREASED THE OVERALL
POTENTIAL FOR ADVISORY LEVEL WINDS TO REACH THE SURFACE BY LATE
MORNING THROUGH THE AFTERNOON. THEREFORE, HAVE COORDINATED THE
ISSUANCE OF A WIND ADVISORY OVER NORTHERN IOWA, WITH SUB-
ADVISORY CRITERIA LEVELS EXPECTED ELSEWHERE BUT EVEN LESS SO
FURTHEST SOUTH. TEMPERATURES WILL REMAIN ABOVE NORMAL AS WELL
GIVEN THE RETURN OF WARM AIR ADVECTION, WITH FORECAST HIGHS IN
THE 50S TO THE NORTH AND THROUGH THE 60S FURTHER SOUTH, WHILE
DEWPOINTS DROP QUITE DRAMATICALLY INTO THE TEENS OVER IOWA. THE
RESULT WILL BE VERY LOW RH VALUES IN THE TEENS TO LOW 20S,
PAIRED WITH THE AFOREMENTIONED WINDY CONDITIONS THAT WILL
RESULT IN CRITICAL FIRE WEATHER CONDITIONS ACROSS CENTRAL IOWA.
THEREFORE HAVE ISSUED A FIRE WEATHER WATCH FOR THE ENTIRE CWA AT
THIS TIME AND THE EXPECTANT CONVERSION TO RED FLAG WARNING
EARLY WEDNESDAY.
THE ACTIVE PATTERN OF WEATHER WILL KEEP HOLD TOWARDS THE LATTER HALF
OF THE WORK WEEK, AS LEE-SIDE CYCLOGENESIS OFF THE COLORADO ROCKIES
DEVELOPS A DEFINED SURFACE LOW WEDNESDAY EVENING, WHICH IS
EXPECTED TO MOVE EASTWARD, MOVING DIRECTLY OVER IOWA BY THURSDAY
AFTERNOON. MODEL GUIDANCE CONTINUES TO SHOW AN INCREASE IN
THETA-E ADVECTION AND THE WARMEST TEMPERATURES OVER SOUTHEASTERN
IOWA IN THE 50S, WITH LOWER VALUES NORTH AND WEST, ESPECIALLY
OVER NORTHWEST IOWA AS THE FREEZING LINE AND DEFORMATION ZONE
ARRIVES IN COINCIDENCE IN RELATION TO THIS DYNAMIC SYSTEM.
MODELS GENERALLY PING NORTHERN IOWA AS HAVING THE MOST LIKELY
POTENTIAL FOR ACCUMULATING SNOW OVER 1-2 INCHES, THEN DECREASING
FURTHER SOUTH, GENERALLY AROUND TO LESS THAN AN INCH SOUTH OF
I-80. ANY SHIFT IN THE SYSTEM COULD BRING SOME SUBSTANTIAL
CHANGES IN AMOUNTS, SO SOMETHING TO CERTAINLY KEEP AN EYE ON
OVER THE NEXT FEW FORECAST CYCLES.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1125 PM CST TUE FEB 17 2026
SHOWERS AND ISOLATED THUNDERSTORMS WILL BE MOVING EAST OF THE
AREA EARLY IN THE PERIOD. STRONG AND GUSTY WINDS AND LOW LEVEL
WIND SHEAR WILL BE THE AVIATION FOCUS OVER THE NEXT 24 HRS.
GUSTY WINDS WILL TURN WESTERLY THEN MAXIMIZE WEDNESDAY MORNING
AND INTO THE EARLY AFTERNOON PRIOR TO DIMINISHING. A FEW GUSTS
OVER 45 KTS ARE POSSIBLE OVER NORTHERN IOWA. LOW LEVEL WIND
SHEAR IS POSSIBLE THROUGH 12Z.
FIRE WEATHER
ISSUED AT 1125 PM CST TUE FEB 17 2026
THE FIRE WEATHER WATCH HAS BEEN UPGRADED TO A RED FLAG WARNING
FOR THE ENTIRE AREA. THE WIND IS TRENDING STRONGER ON WEDNESDAY
AND THESE WINDS COMBINED WITH VERY LOW RELATIVE HUMIDITY VALUES
BELOW 25% AND CURED FUELS, WILL LEAD TO CRITICAL FIRE WEATHER
CONDITIONS. EXTREME FIRE GROWTH COULD OCCUR WITH ANY FIRES
ACROSS IOWA ON WEDNESDAY.
DMX WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY FROM 8 AM TO 4 PM CST WEDNESDAY FOR IAZ004>007-
015>017-023>028-033>039-044>050.
RED FLAG WARNING FROM 10 AM TO 7 PM CST WEDNESDAY FOR
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097.
DISCUSSION...BURY
AVIATION...DONAVON
FIRE WEATHER...DONAVON
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