Dog Days of Summer: Heat, humidity, another severe risk

Welcome to the Dog Days of Summer.

The ancient Greeks believed when the dog star Sirius appeared to rise in the July morning sky it added additional heat to the intense summer sun.

National Geographic elaborates on the meaning of the phrase "Dog Days."

To the Greeks and Romans, the “dog days” occurred around the day when Sirius appeared to rise just before the sun, in late July. They referred to these days as the hottest time of the year, a period that could bring fever, or even catastrophe.

“If you go back even as far as Homer, The Iliad, it’s referring to Sirius as Orion’s dog rising, and it describes the star as being associated with war and disaster,” said Jay B. Holberg, author of Sirius: Brightest Diamond in the Night Sky and senior research scientist at the University of Arizona Lunar & Planetary Laboratory. “All throughout Greek and Roman literature, you found these things.”

The phrase “dog days” was translated from Latin to English about 500 years ago. Since then, it has taken on new meanings.

Warmest two weeks of the year in Minnesota On average we're now entering the warmest two weeks of the year in Minnesota. According to my trusty Minnesota Weatherguide Environment Calendar the average daily high and low temperatures at MSP Airport peak at 84 and 64 degrees now through July 22nd.

Steamy Tuesday

Tuesday feels all of July. Temperatures and dew points surge into the tropical zone Tuesday afternoon. Temps will push 90 in southern Minnesota. Southerly winds push the tropical moisture plume north again. Dew points surge into the sultry 70s by late Tuesday.

Severe risk returns Tuesday night

The next wave of storms fires Tuesday evening across northern Minnesota and works south and east. NOAA's Storm Prediction Center has upped the severe risk into the "enhanced" category Tuesday evening.

It looks like another late evening for metro storms. The best timing suggests storms will fire Tuesday evening in the eastern Dakotas, then march southeast, approaching the Twin Cities in the hours surrounding midnight. Here's NOAA's NAM 3 km resolution model.

Heat builds into next week?

The longer range jet stream pattern suggests heat will build this weekend into next week across the Upper Midwest.

So far we've bagged 7 days at or above 90 degrees at MSP Airport this season. That's slightly ahead of the average pace for 11 days of 90+ degree summer heat. I think we'll be close to 90 this weekend in the Twin Cities. And we could ad 2 to 3 days next week. Overall I can see 3 to 6 days of 90+ heat likely in the next two weeks, with additional days in the upper 80s.

Dog Days indeed.