FXUS63 KDMX 051952

AFDDMX



Area Forecast Discussion

National Weather Service Des Moines IA

252 PM CDT Wed Aug 5 2026



.KEY MESSAGES...



- Flood Watch remains in effect for southeast Iowa this evening.

  Heavy rain continues to trend south.



- Brief break from rain Thursday followed by storm chances, some

  severe, Friday and Saturday.



- Active pattern continues through much of the forecast. 



&&



.SHORT TERM /THROUGH THURSDAY/...

Issued at 250 PM CDT Wed Aug 5 2026



Showers and storms continued across the southeast this afternoon, 

leaving a swath of 3-5" of rain in its wake in parts of southwest 

Iowa. Have maintained the Flood Watch for flash flooding in 

southeast Iowa for the remaining storms as well as the chance of 

storms to form later on this evening. That said, confidence is 

decreasing in flash flood potential within the watch. The continued 

precip today, the instability axis has been pushed into Missouri and 

the synoptic cold front was already out of the state earlier this 

morning. The LLJ nose will come close to the state line tonight, but 

the factors mentioned above favor the max of QPF staying out of 

Iowa. This solution is supported by CAM guidance this afternoon.



Dense fog will form tonight as the winds calm. Highest confidence in 

dense fog will be where most of the rain fell over the last 24 

hours. Anticipate visibility reductions for the morning commute. A 

Dense Fog Advisory will likely be issued later on tonight. A 

reprieve for precipitation comes on Thursday and smoke will filter 

the sky above. Highs will be near 80 degrees.



&&



.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

Issued at 250 PM CDT Wed Aug 5 2026



The relief from rain will be fairly short lived as an active weather 

pattern sets up. An upper-level ridge sets up in the desert 

southwest and locks Iowa in northwest flow for the remainder of the 

forecast period. We start seeing effects on Friday when moisture 

returns. Severe weather is possible Friday when storms fire on the 

instability gradient with 40kts of deep-layer shear to work 

with. Will need to monitor for supercell potential as the shear 

orientation is orthogonal to the boundary. If supercells 

materialized, the hail threat increases due to most of the shear

residing above the inflow layer and the steepening lapse rates 

from the reestablished EML. The front will reorient itself for 

Saturday, but severe weather will remain in play as instability 

quickly recovers and deep-layer shear remains favorable across 

the state.



Northwest flow continues into next week with multiple chances 

for thunderstorms and high temperatures heavily dependent on 

storm placement. This pattern continues into next weekend, as 

highlighted by the CPC 8-14 day outlook.



&&



.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...

Issued at 1241 PM CDT Wed Aug 5 2026



Rain and thunderstorms continue to fester across southern Iowa

and MVFR and IFR cigs exist as a result. Have refined TEMPO

groups to reflect worsening cigs and vsbys from heavier rain.

Have added prevailing mist to select terminals as fog is filling

in behind the exiting rain. It's possible that vsby restrictions

will begin sooner than depicted for KDSM and KFOD. Lowered vsbys

late in the nighttime hours with confidence increasing in LIFR

vsbys for a time due to the fog.



&&



.DMX WATCHES/WARNINGS/ADVISORIES...

Flood Watch until 7 PM CDT this evening for IAZ086-096-097.



&&



$$



SHORT TERM...Jimenez

LONG TERM...Jimenez

AVIATION...Jimenez