CHAMBER OF COMMERCE WEATHER...
If you were trying to sell weather this August chances are your wallet would be fat. Extremely pleasant conditions have blessed us at a time of year when conditions are typically stagnant, hot and humid. As you can see that's not been the case this year. Check out the temperatures so far in the Quad Cities and Cedar Rapids. Highs have been in the upper 70s and low 80s with lows in the low 50s (upper 40s in a few spots). Throw in sunny skies and very low humidity and you have yourself something to sell!
These are the temperature departures over the past 5 days. Parts of SE Iowa and central Illinois have been running 10-12 degrees below normal. If you are going to run deficits like that, now is the time to do it as opposed to winter.
Here's the 500mb jet stream flow which has brought us the chamber of commerce weather.
Holding onto a pattern like this for any period of time in early August is next to impossible and already signs of change are showing up. Notice on the satellite how return flow moisture is steaming into the Plains as our cool high pressure drifts off to the east. The southerly wins will bring warmer temperatures, much higher humidity, and even some rain chances in the days to come.
The first crack at rain reaches my area Thursday. While some models show a few showers reaching my counties in eastern Iowa by late day, I suspect the existing dry air will keep most of the rain up in the clouds. Saturation prospects are better Thursday night and that's when a few elevated showers or storms are possible. In general, amounts look to be very much on the light side with the best chances in my far western counties. The 3k NAM indicates amounts that look like this through Friday night. Not much shown east of the Mississippi.