Jeff Masters - Sizzling October Sunday for Northern Plains

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=3152
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Sweaters and jackets lay dormant, replaced by T-shirts and shorts, for many residents of the United States over the weekend. Temperatures soared into the 80s and 90s across many parts of the country west of the Mississippi River. It wasn’t exactly chilly across the eastern U.S., either, with sunshine and pleasant 60s and 70s the rule over most areas. The most impressive extremes occurred on Sunday over the Northern Plains, where an already-warm airmass from the Rockies warmed even further as west winds pushed it downslope.


Figure 1. High temperatures observed on Sunday, October 11, 2015. Image credit: The Weather Channel.


Even though we’re now into mid-October, when average temperatures are falling fast, several locations managed to break monthly records for heat on Sunday. Many others experienced their warmest (or hottest) day ever recorded so late in the autumn, as catalogued by weather.com. In a number of cases, the readings on Sunday were one to two weeks later than any comparable heat in more than a century of record-keeping.

Locations where Sunday was the warmest day notched so late in the autumn include the following (thanks go to Nick Wiltgen and Linda Lam at weather.com for some of the record-heat data used below):