040
FXUS63 KDMX 040832
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 AM CDT SAT APR 4 2026
KEY MESSAGES
- BRISK, GUSTY WINDS FROM THE NORTHWEST AND COOL TODAY.
- MILDER ON SUNDAY WITH A BIT LESS WIND AND MOSTLY SUNNY.
- OFF AND ON PRECIPITATION CHANCES WITH DRY PERIODS THE FIRST
HALF OF THE WEEK AS CONDITIONS TREND FROM COOL TO WARM.
- A WET PATTERN LATE IN THE WEEK INTO NEXT WEEKEND WITH
INTERVALS OF RAIN AND STORMS. WILL NEED TO MONITOR TRENDS AS
SIGNAL IS PRESENT FOR POSSIBLE FLOODING IN THE REGION, IF NOT
POSSIBLY SOMEWHERE IN THE STATE.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 332 AM CDT SAT APR 4 2026
STORM ACTIVITY HAS SHIFTED EASTWARD OUT OF THE STATE AS SURFACE
LOW PRESSURE OVER NORTHEASTERN IOWA EXITS INTO WISCONSIN THIS
MORNING. IN ITS WAKE, THERE IS PLENTY OF CLOUD COVER BEHIND THE
LOW AND WINDS ARE BECOMING FROM THE NORTHWEST. THESE WINDS WILL
INCREASE INTO THE DAYLIGHT HOURS AS MODEST COLD AIR ADVECTION
(CAA) PREVAILS AND STEEPENS LOW LEVEL LAPSE RATES. THESE STEEPER
LAPSE RATES WILL AID IN MOMENTUM TRANSPORT WITH TOP OF MIXED
LAYER WINDS NEAR 40 KNOTS. WE MAY NOT REALIZE THE FULL POTENTIAL
OF WIND GUSTS GIVEN THAT THE CAA WANES INTO THE AFTERNOON AND
THERE IS A LACK OF A STRONG PRESSURE RISE COUPLET. IT WILL BE A
WINDY DAY NONETHELESS WITH SUSTAINED WINDS FROM THE NORTHWEST
AT 15 TO 25 MPH WITH GUSTS OF 30 TO 40 MPH COMMON. FORECAST
SOUNDINGS ALSO SHOW ELEVATED INSTABILITY BUILDING UP TO AROUND
50 J/KG, WHICH WILL AID IN SPOTTY RAIN AND SNOW SHOWER
DEVELOPMENT BY LATE THIS MORNING INTO EARLY THIS EVENING,
PARTICULARLY AND MAINLY NORTH OF HIGHWAY 30 OVER NORTHERN IOWA,
AS THE MOISTURE CONTINUES TO WRAP AROUND THE DEPARTING LOW
PRESSURE. WHILE NO ACCUMULATION IS EXPECTED, BRIEF VISIBILITY
REDUCTIONS TO AROUND A MILE ARE POSSIBLE AS A SHOWER PASSES ANY
GIVEN LOCATION. HIGHS WILL BE A BIT BELOW SEASONAL VALUES NEAR
40 DEGREES AT THE MINNESOTA BORDER TO NEAR 50 DEGREES AT THE
MISSOURI BORDER.
HIGH PRESSURE WILL DROP INTO THE CENTRAL PLAINS ON SUNDAY WITH
MILDER CONDITIONS AS HIGH TEMPERATURES WILL BE ABOUT 10 DEGREES
HIGHER THAN SATURDAY. WIND WILL NOT BE AS STRONG AS SATURDAY, BUT
WILL STILL AVERAGE BETWEEN 10 AND 20 MPH WITH GUSTS UP TO 30 MPH
UNDER A MOSTLY SUNNY SKY. AS THE HIGH SLIPS AWAY, A BAROCLINIC ZONE
WILL SET UP OVER NEBRASKA INTO WESTERN IOWA WITH LOW LEVEL THERMAL
LIFT AND QG CONVERGENCE TRYING TO SPUR ON LIGHT PRECIPITATION.
HOWEVER, MOISTURE AVAILABILITY WILL BE LIMITED AND FROM THE SOURCE
REGION OF THE PACIFIC WITH FORECAST SOUNDINGS SHOW THAT ACHIEVING
MOISTURE SATURATION MAY BE A CHALLENGE.
LONG TERM /TUESDAY THROUGH FRIDAY/
ISSUED AT 332 AM CDT SAT APR 4 2026
STRONGER LOW LEVEL FLOW AND THETA-E ADVECTION IS FORECAST ON TUESDAY
AS HIGH PRESSURE MOVES OVER THE GREAT LAKES AND SURFACE LOW PRESSURE
MOVES EAST OF THE SOUTHERN CANADIAN ROCKIES. THIS LOW WILL AID IN
TRANSPORTING PACIFIC MOISTURE ACROSS THE REGION. OFF AND ON
PRECIPITATION CHANCES ARE LIKELY TUESDAY INTO WEDNESDAY WITHIN THE
THERMAL LIFT REGIME. AS THE CANADIAN LOW MOVES INTO THE QUEBEC
PROVINCE, THE COLD FRONT WILL LOSE ITS DRIVE SOMEWHERE JUST
SOUTH OF IOWA LATE IN THE WEEK. AS THIS STALLS OUT, PULSES OF
SHORTWAVE ENERGY AND SURGES OF THETA-E ADVECTION WILL INVIGORATE
RAINFALL AND STORM CHANCES FROM THURSDAY INTO NEXT WEEKEND OVER
THE REGION. MANY, THOUGH NOT ALL (E.G. 0Z ECMWF), DETERMINISTIC,
ENSEMBLE, AND AI SOLUTIONS CONTINUE TO POINT TO 1.5 TO 3 INCHES
OF RAINFALL IN SOME PART OF THE STATE IN THIS PERIOD, WHICH
RAISES CONCERNS FOR RIVER FLOODING AND FLASH FLOODING. OF
COURSE, IT WILL ALL DEPEND ON WHERE THE FRONT ENDS UP AS TO
WHERE THE RAIN FALLS, WHICH WILL PLAY A BIG ROLE IN THESE
CONCERNS. RIVERS ARE CURRENTLY RESPONDING TO THE RAINFALL OF THE
PAST FEW DAYS WITH THESE LIKELY TO NOT RETURN TO THEIR PRE-
RAINFALL LEVELS, OR BASE FLOWS. THUS, IN CHANNEL CAPACITY IS
REDUCED. SOILS WILL, TO SOME DEGREE DRY, IN THE COMING DAYS, BUT
ARE LIKELY TO HAVE SOME LEVEL OF REDUCED CAPACITY AS WELL
COMPARED TO THE FIRST PART OF THIS PAST WEEK. NATIONAL WATER
MODEL FORCED BY THE GFS AND NBM ARE SHOWING HIGH ANNUAL
EXCEEDANCE PROBABILITIES (AEPS), WHICH CORRELATE TO MAINLY
WITHIN BANK RISES OR PERHAPS MINOR FLOODING, ON LARGER STREAM
SEGMENTS LATE NEXT WEEK AND WEEKEND. THIS IS ALSO SHOWN IN THE
EXPERIMENTAL 10 DAY HYDROLOGIC ENSEMBLE FORECASTING SERVICE
(HEFS) WITH 30% CHANCE OF EXCEEDANCE SHOWING SEVERAL FORECAST
POINTS HAVING WITHIN BANK RISES AND 10% CHANCE OF EXCEEDANCE
SHOWING ABOUT A HALF DOZEN FORECAST POINTS BREACHING MINOR
FLOOD STAGE.
AS FOR SEVERE WEATHER POTENTIAL LATE NEXT WEEK AND WEEKEND, IT
LOOKS LOW WITH MEAGER AMOUNTS OF INSTABILITY AND DEEP LAYER
SHEAR, WHICH IS ALSO REFLECTED IN THE AI/ML GUIDANCE LARGELY.
WHILE WE WILL BE WATCHING HOW THIS EVOLVES, THE HYDROLOGY AND
FLOODING SIDE HAS MORE CONCERN THAN THE SEVERE POTENTIAL AT THIS
POINT.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1046 PM CDT FRI APR 3 2026
THUNDERSTORMS CONTINUE TO MOVE OUT OF THE FORECAST AREA. A FEW
STORMS MAY LINGER IN VICINITY OF KOTM AFTER 06Z. IFR TO LOCAL
LIFR CIGS OVERNIGHT THAT WILL GRADUALLY IMPROVE ON SATURDAY.
THERE IS A CHANCE THAT MORE STRATUS WILL SURGE BACK SOUTH LATE
SATURDAY EVENING. GUSTY WEST WIND OVERNIGHT AS THE COLD FRONT
MOVES THROUGH. THE WIND WILL INCREASE FURTHER, ESPECIALLY
SATURDAY AFTERNOON AND EARLY EVENING WITH GUSTS NEAR 35 KTS
POSSIBLE.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...ANSORGE
LONG TERM...ANSORGE
AVIATION...DONAVON
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