HOT, BUT CHANGES ARE COMING

We are in the midst of a late-season heat wave across the central US with daily temperatures pushing into the 90s. This trend will continue for several more days before we see a breakdown of the pattern, at minimum briefly, which could also lead to a chance of some thunderstorms as we transition to some cooler temperatures.

Tuesday's highs (above) could flirt with records in the Quad Cities down to Peoria.

The forecast around the Quad Cities region shows temperatures near 90 through Wednesday with a cooling trend towards next weekend. Notice highs likely backing off into the mid-70s with some 'open-the-windows' nights ahead with lows backing off into the mid 50s. Not too bad!

Late this week we do see the ridge break down with a trough eject into the Midwest. This will usher in the cooler temperatures more reminiscent of normal, but could also instigate some thunderstorm activity including a strong storm threat around the Wednesday/Thursday time frame as we will see just enough moisture in place to make it interesting.

The American ensemble, the GEFS, indicates some instability in place Thursday before a cold front sweeps through the region. This will be sufficient for storms at minimum, with some potential for a strong storm threat as well given the upper air support with the limited instability.

Analogs and machine-learning forecasts do indicate low probabilities of severe weather in the region Wednesday. The signal is pretty limited at this point, but I would not be shocked to see these increase a little bit in the days ahead. No formal Storm Prediction Center outlooks are in place.

The European ensemble guidance indicates widespread rainfall of 0.25" late Wednesday into Thursday which again, at minimum, supports the idea of thunderstorm activity with the pattern transition. This would be a nice break to the very dry pattern as of late.

Behind the boundary by Friday we do see cooler temperatures with mid-70s across Iowa and northern Illinois. Nice trends for sure! Long-range forecasts still appear to favor above-normal temperatures to end the month of September, however, but at least we will rid these 90s in the short term.

-Meteorologist Nick Stewart