The ring of fire is locked in place and doing its thing...I guess you could say it's all fired up. For 3 consecutive days rounds of thunderstorms have traveled the edge of the heat dome delivering strong to severe storms and locally heavy rains. Here's the rainfall over the past 7 days, much of this coming since Sunday. This does not include anything that's fallen since 7:00 AM Tuesday. Also, I don't have details but as much as 8" of rain (possibly more) has fallen in NE Iowa Tuesday evening. Serious flash flooding was occurring at the time of this post around Midnight.
Here's a tighter view of my local area. You can see the banding that takes place as individual storm clusters traverse the Midwest. You can also see spots where little to no rain has fallen. Feast or famine, that's the nature of summertime convection.
After the remnants of Tuesday nights storms depart, the stage is set for more steam and storms Wednesday. One difficult challenge Wednesday will be how hot it gets over my area. Outflow boundaries (mini-cold fronts) from the overnight convection may alter the northern extent of the heat by producing clouds and even storms. The 90 degree line could vary anywhere from HWY 20 to I-80. The final position will determine how far north or south heat advisories go when they are issued.
As it stands now the EURO has this for highs with the 90 degree contour up to Waterloo and Dubuque, roughly HWY 20.
Here are the dew points the GFS forecasts. I'm using the GFS because it has been doing a better job handling the low level moisture than the EURO. These numbers are nasty, 82 all the way to Cedar Rapids. That's far worse then Miami will see.
Even if high temperatures end up lower by debris clouds, the extreme dew points will get heat index values up to 100 over most of my area. The far south, especially near and south of I-80 could potentially reach 106-108 degrees. Something to watch.
Late Wednesday afternoon or evening a cold front will descend on northern Iowa and southern Wisconsin. It should be a focus for more convection at that time. Strong to severe storms along with heavy rain will be a threat in some part of my area. The 3K NAM has this for a simulated radar at 10:00 PM Wednesday evening. Another MCS pushing across Iowa.
A break is in the works as the cold front passes Thursday. Cooler and less humid air will return for a couple days. By early next week, the ridge builds again and the ring of fire once again returns to some part of the Midwest... Can you say repeat performance! Roll weather...TS