The heat is on! A strong upper level high pressure ridge, effectively known in the meteorology community has a "heat dome" or a "death ridge" will move from the Ohio Valley late this week into the southeastern U.S. this weekend. Temperatures will skyrocket into the triple digit range from Detroit to Philadelphia southward to Memphis and Montgomery. This "death ridge" is indicated on the 500 millibar pressure chart, or the 18,000 feet level as a large oval with lines ridging around it:
The oval shaped area parked right over the Shoals in Alabama is the center of the high pressure ridge. It will migrate toward Atlanta by this weekend. This map basically shows the level of the 500 mb pressure level at given areas of the country. Heat causes the pressure surfaces to expand, so areas with hotter temperatures will show the lines buckling upward indicating that 500 mb is higher in those locations than those with colder temperatures such as over Thunder Bay in Canada and British Columbia. We as meteorologists use this chart often to see where storm systems are and to get an idea of the general pattern across the country.
Here are some of the record highs that occurred on Thursday, June 29th:
Rawlins WY 92F tied 1961
Bluefield WV 92F
Wheeling OH 94F
Morristown TN 97F
Madison WI 97F tied 1931
Grand Rapids MI 97F tied 1931
London KY 99F **all time June record**
Jackson KY 100F **all time June record**
McAlester OK 100F tied 1954
Greenville MS 101F tied 1925
Knoxville TN 101F
Springfield MO 101F
Fayetteville AR 101F
Joplin MO 102F
Dayton OH 102F tied 1944
Sidney NE 102F
Toledo OH 103F
Louisville KY 103F **all time June record**
Tupelo MS 104F tied 1954
Concordia KS 104F tied 1990
Indianapolis IN 104F **all time June record and hottest since Jul 14 1954**
Muscle Shoals AL 105F
Paducah KY 105F tied 1952
Nashville TN 105F *hottest so early*
North Little Rock AR 105F **all time June record tie Jun 25 2012**
Evansville IN 106F **ALL time June record**
Bowling Green KY 106F tied 1936
Fort Smith AR 106F
Topeka KS 106F tied 1936
Wichita KS 106F tied 1990
Fort Wayne IN 106F **all time record tied 3 other times**
Little Rock AR 107F **all time June record**
Harrison AR 107F **all time June record**
Colombia MO 107F **all time June record**
St Louis MO 108F **all time June record**
Dodge City KS 108F
Russell KS 109F
The heat continues this weekend, and even parts of our area will see 100° heat. The most likely area for these hotter temperatures will be inland sections closer to Hwy 84, near the high pressure ridge aloft. Temperatures will continue hot into Sunday before backing off some by the middle of next week as the high pressure area shifts back to the west. It will remain hot however through the middle of next week, but
we could see some relief from isolated afternoon storms that will flare up from time to time. Stay cool!
Chief Meteorologist Derek Beasley
