textproduct: Des Moines

KEY MESSAGES

- Light rain passing through central Iowa on Friday. Last pleasant day for quite some time.

- Dangerous heat builds in over the weekend with a heat advisory issued for Saturday. Extreme Heat Watch issued Sunday through Monday.

- Additional showers and storms are possible later this weekend into early next week, with some potential for severe weather. Timing and location will be better determined in the coming days.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 149 AM CDT Fri Jul 24 2026

Make sure you get out and enjoy Friday, as it will be the last day with comfortable temperatures for quite some time. As we kick off Friday morning, light showers will continue to spread across northern Iowa, with temperatures sitting in the mid-60s. Showers will continue to drift to the south as we progress through the morning. We will maintain precipitation chances along the Iowa/Missouri border through sunset tonight. Highs on Friday will top out in the mid to upper 70s under a mostly cloudy sky. Rain will eventually move out and ridging begins to build in, ending our pleasant streak of beautiful days. Summertime heat looks to return starting on Saturday, and it will return with a vengeance.

Ensemble guidance gives a strong signal that dangerous heat is building in on Saturday. With persistent southerly flow and crops in peak evapotranspiration, dew points will have no trouble climbing into the mid 70s and perhaps at times reaching the upper 70s over the weekend. Temperatures are expected to climb into the upper 80s to lower 90s across the state. The highest confidence for highs in the 90s will be over the western half of the state on Saturday, as we mix down some of those warmer temperatures to the west. For this reason, a heat advisory has been issued for the western and central parts of Iowa Saturday, as heat indices will push the 105 mark in several spots. Reasons for keeping it out of the eastern half of the area include: first, we won't have as warm of temperatures to mix down; and second, guidance hints at smoke returning to central Iowa on Saturday, which may play a small factor in keeping highs slightly lower and preventing higher heat index values.

With dew points and hot temperatures, our atmosphere will be very unstable. However, 850 mb temperatures of 20 degrees celsius or higher will put much of central Iowa under a strong cap. If storms manage to fire along the thermal ridge to the east, there will be enough energy to produce a few strong storms, but the capping should generally hold over our area. Given the conditional for severe storms, a marginal risk has been issued over far northeast Iowa.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 240 PM CDT Thu Jul 23 2026

As the thermal ridge nudges further eastward into the weekend and early next work week, a stronger push of low-level southwesterly flow will bring warmer and more humid air into the Central Plains. This pattern shift will allow for temperatures to rise significantly with values through the 90s, especially Sunday and Monday. Dewpoint values topping out through the 70s, paired with these temperatures, will lead to heat index values near 100-105+ degrees over western Iowa Saturday, and much of the area Sunday and Monday. The upper level northwesterly flow into Iowa though in relation to the closer proximity of the thermal ridge will also introduce additional chances for showers and thunderstorms, particularly into Sunday morning and again late Sunday into Monday. Smoke also could limit highs a bit Saturday as guidance suggests a return through the day. All important things to watch over the coming days, but at least in terms in heat headlines, the potential is certainly there for some areas of Central Iowa. The warm and moist airmass Sunday through early next week will bring about to a substantial increase in instability and favorable shear profiles to reintroduce severe weather potential as various shortwaves round this ridge into the Midwest. At this time, guidance suggests, as mentioned earlier in this paragraph, early Sunday morning and especially late Sunday into Monday morning with the increasing LLJ into Iowa to be possible targets for some potential severe weather, with the SPC highlighting north/northeast Iowa in a 15% risk. Will keep a close eye on this over the coming days as details become more clear. The thermal ridge by midweek next week moves very little, with Iowa still in the ring of fire as additional waves are indicated in long term guidance to pass through, keeping the pattern more on the active side.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 639 AM CDT Fri Jul 24 2026

Light showers are pushing through central Iowa this morning impacting KFOD, KDSM, and KOTM terminals. Showers will begin to clear over the next couple of hours at these terminal sites. Clouds will begin to thicken this afternoon and ceilings will drop across all terminal sites. KDSM and KOTM will see ceilings drop to MVFR restrictions around 20z. Clouds will continue to lower tonight into early tomorrow morning. Confidence is high that all terminal sites will hit IFR restrictions around 06z. LIFR will be possible, but confidence is not high enough to introduce it at this time.

DMX WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon Saturday to noon CDT Sunday for IAZ004>006-015-016-023>025-033>036-044>048-057>060-070>073-081- 082-092-093. Extreme Heat Watch from Sunday afternoon through Monday evening for IAZ004>007-015>017-023>028-033>039-044>050-057>062- 070>075-081>086-092>097.