018
FXUS63 KDMX 161958
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
258 PM CDT Wed Jul 16 2025

.KEY MESSAGES...

- Diminishing storm chances tonight overall, but some
  storms/locally heavy rain possible far south late tonight
  (~30-40% chance). Severe risk low.

- Drier & cooler Thursday.

- Multiple rounds of showers/storms this weekend with potential
  for heavy rain. Slight Risk (Level 2 of 4) ERO for Friday-
  Sunday.

&&

.DISCUSSION...
Issued at 228 PM CDT Wed Jul 16 2025

Surface low continues to push eastward early this afternoon into
northeast Iowa/southwest Wisconsin with the associated surface cold
front already largely through the area as of early afternoon. This
has resulted in quite pleasant temperatures having already arrived
in much of the area with temperatures in the 70s to low 80s. The
lingering rain from the MCV this morning in the north/northeast has
also largely diminished into early this afternoon with just a few
showers or sprinkles remaining north central to northeast. With the
location of the front and associated warm sector, storm chances for
the afternoon and evening have pushed southward into Missouri and
considerably diminished PoPs as a result. Some may see a brief
shower or sprinkle still this afternoon, but otherwise a largely
pleasant afternoon and evening are in store for much of the area.
CAMs still suggest late evening shower/storm development along the
elevated boundary which was forecast to be in southern Iowa with
many of the evening/overnight runs but 12Z data has pushed this
boundary further south as well keeping most of the precipitation
chances right along to south of the IA/MO border as well. Although
pwat values reach between 1.5-2" with favorable warm cloud depths
and the corfidi vectors pointing in line with the boundary in
southern Iowa, the LLJ is not particularly robust tonight nor in a
favorable location, and instability values also wane through the
evening hours. All this being said, there could be some locally
heavy rain with any showers/storms that develop far south late
tonight (after 10 pm), but given antecedent drier conditions,
continuing maturing crops, and more capacity in southern Iowa, the
hydro threat for the night has also diminished given forecasted
rainfall amounts are largely all less than 1" with higher amounts
into northern MO. Should some locally heavy rainfall occur north of
the border, some localized ponding could occur, but overall the
hydro and severe risk through the night are both low with any rain
far south ending into early Thursday morning.

Temperatures tonight and Thursday will both be cooler with lows
tonight in the 50s to low 60s and highs on Thursday in the 70s.
Similar temperatures are expected into Friday, though afternoon
temperatures warm a bit more southwest into the low 80s as the
surface high which moves in early Thursday pushes off to the east on
Friday returning low to mid-level flow out of the south to southwest
respectively allowing for the warming temperatures but also a stream
of moisture off the Gulf which largely persists through the weekend.
Multiple shortwaves will move through the region at times from later
Friday through the weekend within the upper zonal flow to start the
weekend before upper ridging develops into Sunday. This will bring
the return of periodic shower and storm chances through the weekend
though location and timing remain more uncertain with guidance not
in good agreement. Overall, better rain/storm chances look to be
overnight into early morning Friday night through Sunday night with
some drying through the midday periods Saturday and Sunday. Will
continue to evaluate the severe threat with time as guidance comes
into better agreement but setup favors multiple rounds of heavy rain
as noted in the WPC Excessive Rainfall Outlooks (EROs) for days 3-5
(Friday-Sunday).

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1241 PM CDT Wed Jul 16 2025

Lingering rain showers from the overnight activity continues to
diminish early this afternoon in the northeast with the main
aviation impacts from the lingering lower ceilings with a
combination of VFR to MVFR CIGs prevailing at midday. A few IFR
CIGs may occur at times as well, especially north to northeast,
into this evening though extent of and timing of lower ceilings,
especially north, remains a bit more uncertain and updates may
be needed. Additional rain chances may impact KOTM late tonight
into the early overnight but kept with prob30 group due to
location uncertainty with activity potentially occurring south
of the terminal. Widespread improvements expected into Thursday
morning as VFR conditions return to all terminals.

&&

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

&&

$$

DISCUSSION...05
AVIATION...05