Tonight: Showers and thunderstorms especially north
Wind: SE 5-10 mph
Thursday: Becoming mostly sunny, warm & humid; thunderstorms possible late
Wind: S 15-35 mph
Our summer in September weather will continue for another day before a strong cold front will send temperatures crashing with much cooler and less humid air arriving just in time for the weekend.
WEDNESDAY NIGHT / THURSDAY
Showers and thunderstorms the last couple of days have been tied to a frontal boundary that has been laid up around the area. It will slowly progress north tonight igniting another round of showers and thunderstorms with a risk for heavy rainfall mainly north of Highway 20 towards the state line. Amounts of 1-3" with locally higher amounts aren't out of the question. As a result, a **FLASH FLOOD WATCH** is in effect for counties north of Highway 20 until 1 p.m. Thursday. Further south, rain chances will be more isolated. Temperatures will be mild with 60s by morning.
Showers and thunderstorms will wind down early Thursday as the front pushes further north into Minnesota. Skies will become mostly sunny and with a blustery south wind gusting at times over 30 mph, warm and humid air will surge in making it feel more like July. High temperatures will climb into the 80s and low 90s. Humidity levels will also be running high and heat index (feels like) values could reach the mid/upper 90s and close to 100 for some.
A strong cold front will generate showers and thunderstorms in western Iowa late Thursday afternoon. They will sweep through the area by late evening and should be weakening as they do, but some high wind gusts and locally heavy rainfall will be possible in the stronger thunderstorms.
FRIDAY INTO THE WEEKEND
Once the cold front clears, a strong Canadian high pressure will bring in much cooler air and we'll transition from summer to fall quickly. Friday will be a blustery day as northwest winds usher in the cooler air with high temperatures in the 60s to 70 under partly sunny skies.
High pressure will get established by Saturday morning with low temperatures in the 40s and perhaps some upper 30s in northeast Iowa. That is chilly! The weekend will feature plentiful sunshine and pleasant high temperatures in the 60s and 70s.
Meteorologist Brandon Marshall
Weather First Team
Today's Record Temperatures