'Ring of fire' pattern fueling severe storm potential in far southern Minnesota

Intense heat dome across the central U.S. providing fuel for possible severe storms

Severe weather risk areas
Severe weather risk areas Tuesday.
National Oceanic and Atmospheric Administration Storm Prediction Center, via Iowa Emergency Management

You’ve probably heard the phrase “hotter than the Fourth of July.” Well, this year’s Fourth of July heat is carrying over into the Fifth of July with a massive heat dome across the central United States.

Temperatures will approach the 100-degree mark across much of Iowa and Nebraska:

Forecast high temperatures Tuesday
Forecast high temperatures Tuesday.
National Oceanic and Atmospheric Administration

The steamy air mass under the heat dome is also producing oppressively tropical dew points in the 70s to even 80-plus degrees!

That dome of heat and moisture is fuel for potentially severe storms along the northern edge of the heat wave.

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The contrast of cooler air to the north across northern Minnesota where temperatures are in the 60s and 70s provides a favored zone for thunderstorms to run along the northern boundary of the heat dome.

Ring of Fire
Ring of fire favored storm zone.
Oklahoma Mesonet

Meteorologists call that a “ring of fire” pattern. Areas around the periphery of these massive high-pressure heat domes are also favorable zones for derecho formation.

Derecho formation
Derecho formation.
NOAA

The National Oceanic and Atmospheric Administration’s Storm Prediction Center has painted the area with a moderate risk (4 of 5 categories) for severe storms Tuesday afternoon and evening. The moderate risk zone includes parts of southwest Minnesota, northwest Iowa, and southeast South Dakota:

Severe weather risk areas
Severe weather risk areas Tuesday
NOAA Storm Prediction Center, via Iowa Emergency Management

A bowing line of severe storms is racing across the region as of this post, and will roll through northwestern Iowa into Tuesday evening.

People in southwestern Minnesota should stay aware for possible severe weather warnings as the line moves by through Tuesday afternoon.