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In this week's forecast: Steamy heat and the remnants of Barry

I hope you’ve enjoyed the third consecutive gorgeous and comfortable Sunday and the relative comfort of Monday.

We are headed into another week of building steamy heat, the heat only being mitigated by remnant moisture from Barry. It won’t be Barry itself as an intact tropical system, but the remnant low will still be bring abundant moisture to the Midwest and our region, focusing on Wednesday.

This is a forecast map for Wednesday, with the low over Illinois being made up of the former tropical cyclone Barry — minus the “oomph.”

The overall rainfall distribution will be very uneven, as is usually the case with summertime convective cells. But there will be enough precipitable water available to make rain for a few tropical downpours, which could cause strictly localized flooding in a few spots. The uneven distribution can be seen in this high-resolution model.

Since no model can pinpoint precise locations of cellular torrential downpours two days in advance, please do not assume that heaviest bull's-eye over southern Erie County will actually end up in that location.

There will probably be a few scattered thunderstorms developing for a portion of Tuesday, with an approaching warm front. Once that front goes by, dew points will jump upward, and the mugginess will commence in earnest. Convective activity will likely increase later Tuesday night into Wednesday, with some lingering activity still around into Thursday. A lower-resolution model is more pessimistic with heavy rainfall, showing a larger swath of 2-plus inches amounts by Thursday.

However, because it is less detailed than the first model, I believe the amount of coverage for that heaviest rain is overdone.

Once the convection thins and more sunshine breaks through later in the week on a very humid southwestern flow, the heat will rebuild. With a hot ridge of high pressure to our south, Friday may be the hottest day. Here is the surface setup.

Actual project high temperatures push 90 inland from Lake Erie, although Lake Erie shoreline temperatures will benefit from the cooler (low 70s lake temp) lake waters.

At least on Friday, there will be more of a lake breeze than there was on the oppressive Fourth of July. Take a look at the heat elsewhere, such as in New York City and District of Columbia, where there will be no helpful lake breeze. Locally, Friday's southwestern flow may confine most convection to the edge of the lake breeze, mainly inland to the south and east of the metro area.

Heat and humidity hold into Saturday with some sunshine. The proximity of a stationary front may still trigger a few thunderstorms, but most of the day will be rainfree. Courtesy of Michael Ventrice and IBM’s the Weather Company, here are modeled heat indices for Saturday:

It will be steamy here, but absolutely brutal elsewhere. And here are modeled Saturday temperatures from IBM’s Deep Thunder  model. Note the vast difference from Buffalo’s lake-influenced high to Cleveland and Detroit, where there will be no lake influence:

Models seem to push that front just a little south of Western New York for Sunday, but not very far. If that occurs, Sunday would be a little more comfortable, but not so crisp as the last three Sundays. Pardon the self-censorship, but I’m not even going to show you the American GFS model dew points for this weekend, if you don’t mind. They are Houston-esque, and I firmly believe they are unrealistically high.

So when is some meaningful relief likely? (I’m ignoring those among you who enjoy the lack of evaporating sweat, whom I regard as sturdier but wacky.) The upper air pattern will shift from that hot ridge of high pressure being stacked up over us later this week.

A new upper air paradigm will evolve the following week, when the hot ridge shifts west and some comfortable troughing sets up over the Great Lakes.

If this ensemble verifies, and I am confident it will since this trend has been showing up for a week, it will be cool enough to dance in the streets. I’m a rotten dancer, but I may join you.

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