375 
FXUS63 KDMX 082335
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
635 PM CDT Mon Sep 8 2025

 ...Updated for the 00z Aviation Discussion...

.KEY MESSAGES...

- Scattered showers and thunderstorms return to the area 
  tonight through Tuesday.

- Warmer weather will build in later this week, with daily high
  temperatures well into the 80s from Wednesday onward and
  nearing 90 by Friday. Rain chances return again later next 
  weekend.

&&

.DISCUSSION...
Issued at 304 PM CDT Mon Sep 8 2025

Upper-level pattern shows a weak upper-level trough in eastern NE/KS 
early this afternoon that was associated with early day showers and 
cloud cover in eastern NE that have largely struggled to move into 
Iowa given dry air still in place. This weak trough will continue to 
slowly push eastward tonight through Tuesday before upper-level 
ridging returns Wednesday, persisting through at least the end of 
the work week. In the short term, this trough continues to be 
associated with scattered showers and a few storms from late tonight 
through Tuesday though QPF remains overall limited. Coverage and 
timing continue to remain in question as well with CAMs all over the 
place and global models trending towards later with more limited 
coverage west/southwest tonight into early Tuesday and then again 
north Tuesday afternoon. The main reason for this continues to be 
the dry air as discussed in the last several updates/discussions 
which remains robust in soundings initially but then remains to a 
lesser extent above and below the mid-levels that do eventually 
saturate. The end result is slowed down PoPs tonight followed by 
wider coverage than is likely needed for shower/storm chances 
tonight into Tuesday. Expect some trimming to continue to occur
in subsequent updates with some locations staying dry, some 
seeing only a few sprinkles, and some maybe receiving a bit more
robust shower or thunderstorm that could have some gusty winds 
as well given the dry air already mentioned. The main 
instability axis remains to the west tonight and although does 
start to slide eastward into Tuesday afternoon, remains on the 
more minimal side, most values under 1000 J/kg of MUCAPE. Shear 
also remains quite weak, generally less than 20-25 knots of bulk
shear from tonight through tomorrow night which together with 
instability keeps severe storms out of the forecast, though as 
noted above, a stronger storm could have a stronger wind gust. 
On the note of winds, breezy winds this afternoon thanks to an 
increasing pressure gradient and good mixing will actually 
remain a bit more elevated tonight and not decrease as much as 
typical in the evening as the pressure gradient remains tighter 
through the day Tuesday. The other feature of note is wildfire 
smoke being brought in from the northwest in the upper levels 
keeping skies hazy for locations that do start to clear out from
the overarching cloud cover moving in tonight lingering into 
tomorrow with the shower/storm chances. 

Drier conditions are then forecast Wednesday through the end of the 
week as the aforementioned ridge moves in. The dry forecast 
will be paired with increasingly warmer temperatures as the 
thermal ridge moves eastward but current NBM temperatures are 
actually the extreme high end outlier in the forecast 
distribution and may be overdone. There is confidence it will 
certainly be warmer heading into late week/weekend with 
temperatures in the 80s to near 90, but temperatures well into 
the 90s as seen in the extended forecast on Saturday are an 
outlier at this point and may need some further adjustments over
the next few days.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... 
Issued at 635 PM CDT Mon Sep 8 2025

While clouds will increase through the first half of the period
and prevail through the latter half, conditions will remain VFR.
Gusty winds from the south will lose their gustiness quickly
this evening, but winds will remain elevated and breezy through
much of the period within a few knots of 10. The increase in 
cloud cover also corresponds to an increase in scattered showers
and isolated storm chances. However, those chances begin after 
6z and remain largely below 30%. Thus have continued to not 
advertise any SHRA/TSRA as impact to any terminal is too
uncertain to include with any level of high confidence.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...05
AVIATION...Ansorge