794 
FXUS63 KDMX 201848
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
148 PM CDT Sun Sep 20 2026

.KEY MESSAGES...

- Heavy rain concerns have largely diminished, but rain remains
  common through late Monday night. New rainfall amounts
  generally up to a half inch.

- Fog also possible Monday morning, bringing visibility impacts
  to the morning commute.

- Cool, dry weather expected for the midweek. Next chances of
  rain creep into the west late in the period.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 145 PM CDT Sun Sep 20 2026

Northeast flow advected in dry air near the surface today which 
chewed away at some of the drizzle/fog that was common last night 
and this morning. What was left was a blanket of stratus and 
lingering pockets of mist in southern Iowa. More low-level stratus 
could be seen incoming from the north on satellite. At the synoptic 
level, an embedded closed low was analyzed over Wyoming, its 
presence leading to some southerly flow and convection in the High 
Plains. Highs this afternoon likely won't leave the 60s thanks to 
the solar insulation, save for far southeast Iowa.

Tonight, theta-e advection will battle against easterly flow from a 
high near the US-Canada border. Backed winds at 850 will converge 
along this dry flow which will be enough convergence for showers and 
a few storms in northern Iowa, but the reduced moisture transport 
has reduced our concerns for heavy rain. On to Monday, an embedded 
closed low will move across the state and be met with a secondary 
vort max from behind. This forcing will be enough to keep 
precipitation going, but as the high positions itself over the Great 
Lakes, its influence will increase, putting a limiter on available 
moisture for the forcing to summon. Cumulatively, this time period 
will amount to two tenths of an inch to perhaps half an inch in 
northern Iowa where both rounds are most likely. Fog will build in 
for Monday morning with visibility reductions common once again.

Temperatures Monday will be some of the coolest this week. 
Highs may reach 60 degrees, but much of the state will be in the
upper 50s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 145 PM CDT Sun Sep 20 2026

High pressure will skirt along the US-Canada border and east of the 
Great Lakes with time. As a result, Iowa will keep an easterly 
fetch. Upper-level ridging will keep us dry until it's broken down 
at the end of the week. Until we get there, the main theme this week 
will be partly cloudy skies and highs in the 60s, a timely pattern 
change for the autumnal equinox. A couple of disturbances will move 
onshore and set up an active weather pattern for next weekend with 
rain chances inching their way into western Iowa.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1241 PM CDT Sun Sep 20 2026

MVFR and IFR conditions will be common over the period. A brief
reprieve is expected to occur at KMCW and KALO, but additional
stratus is on its way from the northeast. Have timed its 
arrival. Rain and fog will again be likely overnight, mainly in 
northern Iowa. IFR and LIFR cigs and occasionally vsbys will 
accompany rain by morning. Have hedged more aggressively given 
trends the past few days with lingering fog/stratus.

&&

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

&&

$$

SHORT TERM...Jimenez
LONG TERM...Jimenez
AVIATION...Jimenez