586
FXUS63 KDMX 120343
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1043 PM CDT Sun May 11 2025

 ...Updated for the 06z Aviation Discussion...

.KEY MESSAGES...

- Warm, dry and breezy conditions expected through midweek,
  especially northwest. Highs approaching 90 degrees.

- Scattered thunderstorms possible in the southeast Tuesday
  afternoon (30% chance).

- 70% chance of thunderstorms in the north on Wednesday night
  into Thursday. The threat for severe weather will continue to
  be evaluated.

&&

.DISCUSSION...
Issued at 228 PM CDT Sun May 11 2025

Upper level ridge was centered over Iowa today with the continued
rex block keeping moisture well away from the region. Making
moisture matters worse is the easterlies from the Great Lakes high.
Dew points already well underperformed compared to what was
forecasted at this time yesterday. Have leaned towards the low end
of guidance distribution. Increased dryness also means continued
gustiness with the winds due to efficient mixing, the fastest winds
being in northwest Iowa. This is also the region in closer proximity
to the unseasonably warm thermal ridge that is bringing record highs
to the Northern Plains. The mixture of hot, dry and windy conditions
prompt concerns for fire weather; it is dangerous to burn in
northwest Iowa despite the greenness of the fuels. Expect
sporadic gusts up to 25mph to remain possible until diurnal
decoupling happens with sunset. Highs in northwest Iowa will
make a run at 90 degrees for highs this afternoon.

A surface cyclone in the Northern Plains will continue to pull the
thermal ridge northward, bringing H850 temps at 25C+ all the
way into southern Canada. The Great Lakes High will keep the
worst of the heatwave to our north and northwest this week, but
Iowa will see above-average highs, nonetheless. The warmest
temperatures will be in the north and west. The blocking upper
low will break free starting tonight. This will allow for some
theta-e advection to encroach on the southeastern part of the
state, beginning with midlevel clouds, followed by a slim chance
of showers and storms Monday and Tuesday afternoon (

NWS DMX Office Area Forecast Discussion