"Ring Of Fire" Severe Storms Harassing Various Parts Of The Nation

This map is from last summer and not this week,
but it depicts the series of disturbances
riding above a heat ridge in the middle of the
United States. These disturbances cause
a series of severe storm outbreaks and is known
as a "ring of fire" around the top of the heat ridge.  

In the summer, a common, and sometimes scary weather set up forms, and it's happening now.

It's called the Ring of Fire.

Here's what it is:

A big, very hot area of high pressure sets up somewhere around the middle of the country.

That has happened now, and is responsible for a terrible heat wave in Oklahoma and surrounding areas. Heat indexes are as high as 110 degrees.

(The heat ridge is also over the Desert Southwest, setting that area up for the record heat wave I talked about yesterday.)

Very hot, very humid air always has a lot of potential to feed thunderstorms, and they can grow explosively in this type of air mass. But under the ridge, the air is sinking, which squelches thunderstorms most of the time.

However, along the northern edges of the heat ridge, little disturbances and cold fronts zip basically west to east over the top of the ridge. Often in the eastern United States, the disturbances head southeastward down the front side of the heat ridge over the middle of the country.

These disturbances brush up against the super hot, wet air, and provide the rising air needed to produce big thunderstorms.  All that hot, wet air feeds the fire and storms get cranking.

Yesterday, a broad area from Wisconsin to Kentucky, on the front side of the heat ridge, got lots of severe weather. Nationwide, there were 314 reports of damaging winds and 64 reports of large hail, according to NOAA's Storm Prediction Center.

Today, forecasters are watching the Ohio Valley and Mid-Atlantic states. A pretty strong little storm system  is riding southeastward on the front side of the heat ridge again, and a severe weather outbreak is likely today in these areas.

The combination of the strength of the storm system, and the heat and humidity feeding into it from the south and west means there's a good possibility of very strong winds with some of the thunderstorms

With all that humidity around, the rain with the storms could be heavy, and there is a flash flood watch out for parts of the Middle Atlantic states, including Washington DC and Baltimore.

In fact, the biggest threat today might be the flash flooding. Several inches of rain could fall in just a very few hours with some of the storms in parts of Pennsylvania.

It looks like there might be more severe weather along the northern edge of the heat ridge in Montana and North Dakota Saturday, and over the Upper Mississippi Valley and Great Lakes Sunday and/or Monday.