472
FXUS63 KDMX 031920
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
220 PM CDT Sun Aug 3 2025

.KEY MESSAGES...

- Dry and mild conditions generally continue tonight into
  Tuesday. Light shower/sprinkles possible in far western Iowa
  Monday morning.

- Shower and thunderstorm chances returning mid-week, west on
  Tuesday night then north and central Wednesday night.

- Temperatures warming through the second half of the week.

&&

.DISCUSSION...
Issued at 157 PM CDT Sun Aug 3 2025

The status quo continues for most of today, although the Canadian
wildfire smoke has finally begun to diminish overhead as the upper
trough departs eastward and ridging builds to our west. Despite the
departing trough, surface high pressure will generally remain in
place over the Great Lakes region, keeping roughly east to
southeasterly surface flow going over the area. This has helped
reinforce the drier air overhead, which is doing a fantastic job of
squashing any rainfall drifting eastward out of Nebraska and South
Dakota into western Iowa today. Light radar returns from this
rainfall has all but dissipated over the northwest portions of the
area. Some short range models do still produce scattered light
showers over western into central Iowa this afternoon as well, but
looking at recent trends and model soundings in these same areas,
it`s tough to see how much of anything is going to precipitate this
far east given the dry air in place. Therefore, expecting any
falling precipitation to remain west today.

Later this evening, storms are expected to fire over the plains to
our west, eventually tracking east southeastward toward Iowa
overnight. Yesterday`s model runs indicated this activity may
persist into western and west central Iowa by Monday morning.
However, recent guidance isn`t producing nearly as strong of a cold
pool with the Plains convection, which consequently has lessened the
push of rainfall into Iowa. This has kept most of the rain chances
tied to the north-south oriented instability gradient along the
Missouri River. If this activity does indeed become less organized,
will likely see a similar story to this morning with weak showers
and/or dying storms meandering into western Iowa before meeting the
drier and more stable air mass and quickly dissipating as they
continue eastward. Of course, if things trend back toward what was
being shown yesterday with a more prominent MCS/cold pool tracking
across the plains, we may still see showers punch farther into the
state tomorrow morning. Even in this scenario, the better
instability stays west of the area, cutting the fuel to any
lingering convection that makes it`s way east. The only impacts
these showers may pose, aside from rain, would be some locally
higher winds as the showers dry out.

After the morning chances, Monday into Tuesday morning looks
relatively dry. As we get into Tuesday and Wednesday, we`ll see the
ridge build in from the west, pushing the better instability
and moisture gradient eastward into Iowa. Through this period,
diurnally driven convection will develop along the gradient,
bringing the potential for some showers and storms west Tuesday
night into Wednesday morning, then in north central and central
Iowa Wednesday night into Thursday morning. As mentioned in
yesterday`s discussion, there will also be a warm nose moving
eastward with the ridge. This adds some uncertainty to the
precipitation forecast, especially on Wednesday, as the
progression of this EML will somewhat dictate where showers and
storms occur as they fire along it. The location of this warm
nose will also be impacted by the multiple rounds of
precipitation that occur before Tuesday and Wednesday, further
diminishing certainty. Therefore, the main takeaway is the
potential for showers and storms to a portion of the area on
Tuesday night into Wednesday, and a more widespread area on
Wednesday night into Thursday. A broad look at the environment
through this time frame also suggests the potential for at least
some stronger storms on Wednesday evening as well, primarily
over northern Iowa. However, more specific details regarding
severity will be better discerned in the coming days.

With the thermal ridge building in, we`ll also see high temperatures
climb back into the 80s through the first half of the week, then
potentially the upper 80s to low 90s through the second half.
Dewpoints will increase as well, as the warm, moist air advects
northward with the southerly low level flow. The combination of the
higher dewpoints and warmer temperatures will lead to hot and humid
conditions by the end of the week. Getting into the weekend,
models are depicting a long wave trough dropping southward into
the state. This may help to moderate temperatures into next
week, but not without bringing the potential for more showers
and storms through the weekend. But with that being all the way
at the end of the current forecast period, we`ll have plenty of
time to discuss that more this week. For now, get out and enjoy
the mild temperatures and dry weather!


&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1203 PM CDT Sun Aug 3 2025

VFR conditions prevail through the period as high clouds move
in from the west and scattered cumulus develops central and
east. Winds will be light, generally out of the south to
southeast. Wildfire smoke impacts have ended.

&&

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

&&

$$

DISCUSSION...Dodson
AVIATION...Dodson