COOL HERE, THE TROPICS HEAT UP...
The past week the return of rain to much of the Midwest was a big story. As you can see in the graphic below from the Midwest Climate Center the western Midwest was the big winner with 3-6" amounts from SW Minnesota through western Iowa and NW Missouri.
Behind Monday's rain a big 1020mb high moved into the Midwest bringing a healthy punch of cool dry air.
Wednesday morning with the high centered in Iowa some pretty cool lows were observed with many places in my area falling into the 40s...the coolest readings in about 2 months. Cedar Rapids and Waterloo both registered lows of 47.
Here's some other plots of lows around Iowa and the Midwest. Fall is coming.
The next few days a gradual return of moisture will bring some clouds to the Midwest but little organized precipitation until Saturday night or Sunday. At that time a slow moving trough should have enough moisture to begin producing showers and a few thunderstorms. By the time the system kicks out Monday night the EURO is forecasting rain totals that look like this.
The GFS has these totals for the same period.
While we wait for this event to unfold all eyes will be on the coast of Texas where a strong tropical storm or hurricane (Harvey) is expected late Friday and Saturday. While the winds won't be a major issue the slow movement of the storm and its torrential rains will. Most models are showing rainfall totals in the 10-30" range over a large part of the Texas coast. The GFS showed up to 47" around Corpus Christi in one of its model runs. Severe flooding cloud become a major concern.
You can also see how widespread the flooding rains will be from Texas into Louisiana.
Much of what happens is going to be determined by the track and intensity of Harvey. Here's the various model forecasts put together in what we call a spaghetti plot. Pretty good consistency for landfall along the southeast Texas coast.
We also have intensity forecasts and currently most models are keeping the storm at category 1 or less.
As it stands now, hurricane watches are out for this part of SE Texas