FXUS63 KDMX 210751

AFDDMX



Area Forecast Discussion

National Weather Service Des Moines IA

251 AM CDT Sun Jun 21 2026



.KEY MESSAGES...



- Widespread showers and thunderstorms (60-100% chance) continue

  today, mainly in southern Iowa. The primary threat is heavy

  rainfall and possible flooding, mainly near the IA-MO state

  line. There is also a very low risk of severe weather there.



- Slightly below average temperatures are forecast for most of 

  next week with highs in the 70s to lower 80s. 



- There will be several chances for showers/thunderstorms, with

  a Marginal Risk being introduced for Tuesday.



&&



.SHORT TERM /THROUGH MONDAY/...

Issued at 248 AM CDT Sun Jun 21 2026



Thunderstorm activity remained south of Iowa overnight, instead

the southern half of the state was occupied by steady rain. We 

still have a shot at thunderstorms later this morning and it's 

dependent on activity in central Nebraska. That being said, 

lightning and cloud temperatures have not impressed thus far and

00z CAMs are too strong compared to reality. Still, once the 

nose of the LLJ gets into southern Iowa around sunrise, the CAPE

axis will come near, as will the higher PWATs near 2". Peak 

rainfall amounts will occur before noon in southern Iowa, rain 

more to the north with taper to a drizzle by midday. Rainfall 

amounts over 2" are most likely within the Flood Watch in the 

far south, but most of the area will see amounts near the 1" 

mark.



CAPE values for today have also trended lower; less than 500 J/kg. 

So the Marginal Risk is largely out of the state, save for the far 

southeast. Highs have trended lower. Most of the area will be in the 

mid to upper 60s.



&&



.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...

Issued at 128 PM CDT Sat Jun 20 2026



After the precipitation event ends Sunday night, the synoptic 

pattern next week will feature a predominately northwest upper 

flow regime, due to ridging out west, and a mean trough over the

far northern CONUS. The latest 12Z model guidance indicates 

that several shortwaves will propagate through the mean flow, 

but as per usual, the timing and amplitudes of individual 

shortwaves is more uncertain attm. There is reasonable 

confidence that Tuesday night and early Wednesday, and Friday 

have the highest potential for more organized precipitation. Due

to the NW flow regime, limited low level moisture return is 

expected, thus instability profiles appear mostly meager. As 

such the threat for severe weather next week appears low attm. 

However, it is June, and with stronger wind profiles and colder 

temperatures aloft, we'll need to watch for any sneaky severe 

threats. Finally temperatures next week look to stay below late 

June averages, with highs generally in the mid-upper 70s, maybe 

a few 80 by late week, we'll take that all things considered.



&&



.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...

Issued at 1203 AM CDT Sun Jun 21 2026



Showers will move through the area later tonight into Sunday,

with TSRA possible at times mainly at DSM/OTM. Low ceilings will

also spread in with the rain, again primarily at DSM/OTM where a

period of IFR is likely Sunday morning. Have indicated these

trends in the 06Z TAFs, but amendments are likely overnight and

Sunday based on short-term radar and observational trends.



&&



.HYDROLOGY...

Issued at 128 PM CDT Sat Jun 20 2026



See the main portion of the discussion for the meteorology of the 

event. Flash flood guidance remains mostly unchanged with 6 hr

FFG guidance generally 2.5" to 4". In terms of river flooding, 

little change in thinking. The latest guidance from the National

Water Model, HEFS, and contingency forecasts, still suggest 

that the forecast NWS QPF (or most likely amounts of generally 

1.5" to 3.0") would lead to within bank rises on several rivers,

mainly acrosscentral and southern Iowa. 



However, river flooding could become an issue, but only if rainfall 

amounts on the higher end of the current guidance occur. This would 

generally require widespread QPF amounts in the 4" to 5" range (e.g. 

highest 10% of QPF members). This would likely cause several rivers 

to hit minor flooding, with moderate or greater flooding also a

possibility. This would be most likely across southern Iowa, 

perhaps extending nwd into central Iowa if the higher QPF shifts

nwd (unlikely at this time).



&&



.DMX WATCHES/WARNINGS/ADVISORIES...

Flood Watch through this evening for IAZ085-086-092>097.



&&



$$



SHORT TERM...Jimenez

LONG TERM...Fowle

AVIATION...Lee

HYDROLOGY...Fowle