NOT COOL ENOUGH FOR YOU? JUST WAIT

Saturday was a stellar weather day across the region for the first (official) week of college football and week two is looking even cooler with well below normal temperatures in the forecast as a strong cold front approaches the region later this week bringing in the coolest air of the season.

Saturday's highs were accompanied by sunshine for most of the region Saturday with afternoon highs reaching the upper 70s to mid-80s for much of Iowa and Illinois.

Sunday's highs will be similar, if not a few degrees cooler, around the Quad Cities region with highs in the mid/upper 70s. A few 80s will creep into western Illinois fueled by plenty of sunshine.

A few light showers will be likely to the west across western Iowa and northern Missouri. Southern Iowa, especially south of I-80, will have a chance of a few showers as well but this will generally be quite light. Conditions may be favorable for a few funnel clouds with any shower that develops, but these generally would not reach the ground.

To expand on the funnel cloud potential, there will be an overlap of low-level CAPE as well as low-level wind shear. Again, this generally is not a tornado threat, just an elevated funnel cloud descending from a cloud base. Don't be shocked if there are afternoon Special Weather Statements mentioning the potential.

MONDAY

TUESDAY

WEDNESDAY

Monday and Tuesday, temperatures will gradually hold steady if not increase a few degrees, however by Wednesday the changes are looming with a cold front quickly on approach opening a fetch of Arctic air sending temperatures plummeting to some near-record lows locally by Thursday and Friday. Temperatures could run 10-20 degrees below normal.

If you run a backwards trace, or basically a trajectory of where the air is coming from that we will be dealing with Thursday and Friday, it has its roots firmly in the Arctic. If this was January or February this would be some dangerous cold and snow! That cold front could be a potential watch item for showers and thunderstorms, but given limited moisture in place as well as the very quick-moving nature of the front, heavy rain is not going to be a concern with this.

GFS

EURO

Both global models, the American GFS and the European, show showers and storms along that front with some slight differences on the timing of the arrival. The GFS is early afternoon Wednesday while the Euro is more in the evening. The slightly later timing of the European would favor a higher chance for thunderstorms with some limited instability in place.

Machine learning models also do not indicate a real strong storm threat with this cold front passage.

Additionally, while the severe threat is low so is the overall risk of heavy rain. The blended forecast for rainfall with this cold front locally is a tenth of an inch to a quarter of an inch at best. Again, the limited moisture and quick-moving cold front will likely keep the heavy rain concerns in check.

Behind the cold front we will be in a prolonged stretch of below-normal temperatures. The latest outlook from the Climate Prediction Center has a high chance of cooler temperatures centered around the Great Lakes as strong eastern troughing continues to bring in cooler temperatures. The above forecast is valid Sept. 5-9.

Mid September shows a little bit of a warmer signal in the long-term guidance with ridging returning. This will be watched going forward but the signal has been jumping around a little bit from sustained cooler temperatures to a warmer trend.

Teleconnections like the NAO have been flipping around between positive and negative values in early September which has implications on the overall pattern. I would call the forecast deeper into September much lower confidence than I would like to see. It seems the trend in the last few days has been towards warmer-than-normal temperatures is taking shape and at this point I will lean that way.

Have a great Sunday!

-Meteorologist Nick Stewart