469
FXUS63 KDMX 042340
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
640 PM CDT MON AUG 4 2025
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- VERY LOW CHANCE OF SHOWERS WEST TUESDAY MORNING (<10%)
- MARGINAL RISK FOR SEVERE WEATHER WEDNESDAY MORNING. DAMAGING
WINDS WILL BE THE MAIN THREAT. STORMS TO WEAKEN AS THEY MOVE
SOUTHEAST.
- 90 DEGREE HIGHS RETURN THURSDAY WITH MORE STORMS POSSIBLE OVER
THE WEEKEND.
DISCUSSION
ISSUED AT 245 PM CDT MON AUG 4 2025
BENIGN WEATHER STARTED TO SEE SOME INTERRUPTIONS TODAY IN THE FAR
WEST. SHOWERS POPULATED OVER THE NISH VALLEY AND WESTWARD, ALIGNING
THEMSELVES GENERALLY WHERE THE INSTABILITY AXIS ENDS. SHOWERS AND
STORMS WON'T COMPLETELY DISAPPEAR FROM WESTERN IOWA TONIGHT AND
WHILE THEIR RAINFALL RATES WILL BE ON THE LIGHTER SIDE, THE
WEAK FLOW FROM THE BUILDING RIDGE WILL CAUSE THEM TO NOT MOVE
MUCH. THIS MEANS THAT SOME LOCALLY HIGHER RAINFALL AMOUNTS OVER
AN INCH ARE POSSIBLE, BUT THE SPATIAL COVERAGE WILL BE VERY
SPARSE. SPEAKING OF WEAK FLOW, THERE WON'T BE ENOUGH SHEAR TO
HAVE INTENSE STORMS.
BEHIND THE DEPARTING TROUGH TODAY, NORTHWEST TO ZONAL FLOW WILL SET
IN. A TROUGH IN CANADA WILL INHIBIT SOME OF THE NORTHERN PROGRESSION
OF THE RIDGE AXIS, THIS KEEPING EXTREME HEAT AND EML MOMENTARILY
AWAY. THE INSTABILITY AXIS WILL INCH ITS WAY FURTHER INTO IOWA,
INCREASING PRECIPITATION CHANCES EACH SEQUENTIAL NIGHT. A RECENT
TREND IN HI RES GUIDANCE IS AN MCS DROPPING SOUTH ALONG THE
INSTABILITY AXIS. SOME MODELS SIMULATE THE MCS SOUTH ENOUGH TO BRING
IT INTO IOWA WEDNESDAY MORNING, ALTHOUGH THERE IS DISCREPANCY
IN WHERE THE NOSE OF THE LLJ (THUS INSTABILITY) WILL REACH.
SHEAR WILL BE MARGINALLY FAVORABLE IN NORTHWEST IOWA, MEANING
THAT STRONGER STORMS WITH GUSTY WINDS WILL BE POSSIBLE. THE EML
THEN SETS OVERHEAD, LOWERING PRECIPITATION CHANCES AND RAISING
HIGH TEMPERATURES TO END THE WORK WEEK. HIGHS WILL BE IN THE 90S
THURSDAY AND FRIDAY. ANOTHER TROUGH EJECTS ACROSS THE PNW AND
INTO THE NORTHERN PLAINS, SETTING UP FOR A ROUND OF STRONG
STORMS SOMEWHERE IN THE REGION THIS WEEKEND. TRENDS WILL BE
MONITORED.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 631 PM CDT MON AUG 4 2025
VFR CONDITIONS ONGOING AND EXPECTED TO CONTINUE THROUGH THE TAF
PERIOD. DIURNAL CU CONTINUES TO DIMINISH HERE TONIGHT, BUT
ADDITIONAL AT LEAST FEW-SCT CIGS WILL RETURN FOR TUESDAY. MAY
ALSO HAVE SOME PATCHY FOG AROUND DAYBREAK, BUT EXPECTING MINIMAL
IMPACTS TO TAF SITES. WINDS REMAIN LIGHT, UNDER 12 KNOTS, AND
OUT OF THE EAST TO SOUTHEAST THROUGH THE PERIOD.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...JIMENEZ
AVIATION...05
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