Published: July 17,2017
A ring of fire weather pattern will grip the U.S. into late week, resulting in dangerous heat and bouts of thunderstorms that may contain damaging wind gusts, hail and heavy rain.
Though "ring of fire" isn't a formal weather term, it's sometimes used by meteorologists to describe a particular summertime weather pattern that sets up occasionally.
Here's how it works: Sinking air associated with a strong upper-level high-pressure system east of the Rockies leads to very hot temperatures near its core. Forming a ring around the high's clockwise flow are disturbances aloft that tap into moisture, resulting in bouts of storms near its periphery.
You can see the general setup for this week's ring of fire weather pattern in the graphic below.
Ring of Fire Weather Pattern
Dangerous HeatThe worst of the heat this week will grip areas from the central Plains into the mid-Mississippi Valley and parts of the South.
Excessive heat watches have been issued by the National Weather Service from eastern Kansas into northern/central Missouri and west-central Illinois for a dangerous combination of hot temperatures and high humidity. This includes Kansas City and St. Louis where heat index values are forecast to be 105-110 degrees, particularly from Wednesday into late week.
(MAPS: Forecast High Temperatures)
Highs in the middle to the upper 90s and a few100s will be common across the South during the second half of this week as well. Heat index values of 100-110 degrees are likely during the afternoon hours.
Forecast Highs Late Week
Few daily record highs are forecast to be threatened since that bar is high now that we are in the climatological hottest time of year in most areas.
(MORE: July the Hottest Month in Most of the U.S.)
Ring of Fire StormsThe periphery of the high will be the main focus for stormy activity into late week.
The northern Plains and Upper Midwest will have the highest chance for bouts of severe storms with damaging winds and hail as disturbances ride through the northern side of the high-pressure system. Flash flooding could also be problematic in those regions due to the several bouts of storms rolling through.
Tuesday's Thunderstorm Forecast
(MORE: Threats From the Southwest Monsoon)
The Northeast, Gulf Coast and Southeast coast will also see isolated to scattered showers and storms at times through this week.
Rainfall Potential Through Friday
MORE: Hottest and Coldest Temperatures Recorded in All 50 States
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