It’s going to get sweaty out there Wednesday.
An uber-tropical air mass oozes into Minnesota Wednesday. Dewpoints rise into the 70s, and I wouldn’t be shocked to see an 80-degree dew point reading west of the Twin Cities late Wednesday.
80-degree dew points are rare
It’s rare to see dewpoints hit the 80-degree mark in Minnesota. That’s only happened for a total of 28 hours in the Twin Cities since 1945.
Here’s more on the rarity of 80-degree dewpoints from the Minnesota DNR Climate Working Group.
80 degree dew point temperatures are rare in the Twin Cities historical record. Since 1945, there have been only twenty-eight hours of 80 degree dew points recorded. Ten of those twenty hours came in a ten hour period on July 12 and 13, 1995. 8 hours are from July 17-19, 2011. The highest dew point temperature ever recorded in the Twin Cities was 82 degrees at 3pm and 4pm July 19, 2011. This broke the old record of 81 degrees at 11am on July 30, 1999.
Our inbound air mass meets all the criteria for a heat advisory. Highs in the 90s and dewpoints in the 70s combine to produce heat index values above 100 degrees across southern Minnesota. Prolonged activity outside Wednesday will range from difficult to dangerous.
The heat advisory zone runs west from the Twin Cities.
Storms bubble up along a weak front Wednesday evening in northern Minnesota. The highest risk for severe storms lies north of the Twin Cities.
Twin Cities: Sunrise storms Thursday?
The most likely timing for metro storms looks to be early Thursday morning between 4 and 7 am. Storms blow up in northern Minnesota Wednesday evening and work south toward the Twin Cities early Thursday. Here’s NOAA’s NAM 3 km resolution depiction of storm coverage Wednesday evening into Thursday.
Relief next week
The longer range models still show a distinctly cooler and drier air mass intrusion early next week.