After a busy stretch of weather across Iowa, the week ahead will begin on a much calmer note. Cooler temperatures, lower humidity, and mostly dry conditions will provide a welcome break through Monday before rain and thunderstorm chances gradually increase by midweek.
Pleasant Weather Through Monday
High pressure moving across the Midwest will keep conditions comfortable through Monday. Afternoon temperatures will generally remain in the 70s statewide, which is several degrees below what is typical for mid-June. Humidity levels will stay low, making it feel even more comfortable outdoors.
Sunday’s gusty northwest winds will gradually diminish, and clear skies Sunday night will allow temperatures to fall into the upper 40s and lower 50s by Monday morning. Monday will feature another pleasant day with sunshine, light winds, and afternoon highs once again reaching the 70s.
Small Rain Chances Late Monday Night Into Tuesday
The next weather system will move through the region Monday night into Tuesday morning. Moisture will be limited, which should keep rainfall amounts light and scattered. A few showers and isolated thunderstorms may develop as a weak cold front moves across the state.
At this time, the greatest chance for rain appears to be from late Monday night through Tuesday morning. Most locations that receive rain will likely see light amounts, and severe weather is not expected. Any showers that develop should move out of Iowa by midday Tuesday, allowing for improving conditions during the afternoon.
Temperatures on Tuesday will remain seasonably cool, generally ranging from the upper 70s to lower 80s.
Wednesday Remains the Day to Watch
Attention then turns to Wednesday, which currently appears to be the most active weather day of the upcoming week.
A stronger storm system will move across the Upper Midwest while warmer and much more humid air returns to Iowa. Forecast models continue to show a favorable environment for thunderstorms, including increasing moisture, strong winds aloft, and enough instability to support organized storms.
Thunderstorms may begin developing late Tuesday night and continue into Wednesday morning. Additional storms could redevelop Wednesday afternoon and evening, although the exact timing and locations remain uncertain. One of the biggest forecast challenges will be determining how much impact the morning storms have on the atmosphere later in the day.
The Storm Prediction Center continues to highlight Iowa in a Level 2 of 5 severe weather risk area for Wednesday. While forecast details will continue to evolve over the next few days, some thunderstorms could become severe with damaging winds, large hail, and isolated tornadoes possible.
Current forecast trends suggest the highest severe weather risk may end up focused near and south of Interstate 80, especially across southern Iowa, but confidence is not yet high enough to pinpoint the areas most likely to be affected. Anyone with outdoor plans on Wednesday should continue monitoring forecast updates over the next several days.
Cooler Pattern Continues Late Week
Following Wednesday’s system, temperatures are expected to remain below normal for much of the remainder of the week. Highs Thursday and Friday will generally stay in the 70s to lower 80s with lower humidity returning.
While a few additional weak disturbances may bring occasional chances for showers or thunderstorms later in the week and next weekend, confidence in the timing and placement of those systems remains low. Many areas could experience extended periods of dry weather between any precipitation chances.
Looking Ahead: Cooler and Wetter Than Normal Trend
Long-range outlooks from the Climate Prediction Center continue to favor a cooler-than-normal pattern across Iowa through much of the final third of June.
The June 20-24 outlook shows a 50 to 60 percent probability of below-normal temperatures across Iowa, along with a 40 to 50 percent chance of above-normal precipitation. The June 22-28 outlook continues that trend, favoring below-normal temperatures and above-normal precipitation statewide.
While this does not mean every day will be cool or rainy, it does suggest Iowa will remain in an active weather pattern with periodic opportunities for rainfall and temperatures that are generally cooler than what is typical for late June.
Iowa Weather Outlook
The quiet weather to start the week will provide a nice opportunity to enjoy outdoor activities before a more active pattern returns. The primary forecast concern remains Wednesday, when severe thunderstorms may develop somewhere across Iowa. Forecast confidence is increasing that storms will occur, but the details regarding timing, coverage, and severity will become clearer over the next few days.
Be sure to have the ISCN Weather app installed and check back with IowaWeather.com throughout the week as we continue to refine the forecast and provide updates on Wednesday’s severe weather potential.