Wednesday, July 20, 2016

July 20, 2016: Very muggy! 90 degree temps expected in Duluth on Thursday (SW wind) feels like temps mid-upper 90s. Heat headlines remain in effect in most of the Northland

/Issued 12:50 PM CDT, Wednesday, July 20, 2016/


NWS headlines map as of 12:45 PM today, July 20, 2016.

...Update on the heat for the rest of today and Thursday...

Note:  Click the following links for more information on these heat headlines.  Source, National Weather Service Duluth, Minnesota.

*Excessive Heat Warning* until 9 PM tonight for Walker, Brainerd and Pine River including Cass and Crow Wing Counties in east central Minnesota.

*Heat Advisory* until 9 PM tonight for International Falls, Bigfork, Grand Rapids, Hill City, Aitkin, McGregor, Hinckley and Pine City including Koochiching, Itasca, Aitkin and Pine Counties in northern and eastern Minnesota.

*Heat Advisory 7 AM to 9 PM Thursday for Duluth, Cloquet and Moose Lake including southern St. Louis and Carlton Counties in northeast Minnesota.

*Excessive Heat Watch* remains in effect in all of northwest Wisconsin for Thursday.

At Noon today an area of low clouds remained over much of north central Minnesota.  These clouds are generally found along and north of a warm front which has moved into central Minnesota early this afternoon.

One thing the clouds are doing is helping to keep temperatures in check with 12 PM temperatures running in the mid 70s to low 80s across the Northland.

Dew points have climbed into tropical levels though, and that part of the forecast has verified nicely.  Early this afternoon dew points were in the middle 60s to lower 70s, and these dew point temperatures may rise a few more degrees through the afternoon hours, possibly as high as 75 degrees in some parts of the Northland by later this afternoon.

A lake breeze continues around Lake Superior today and I don't see this lake breeze going away for the rest of today so this will result in temperatures in the 70s closer to Lake Superior.

The atmosphere is loaded with instability and moisture but warm temperatures in the mid levels of the atmosphere has thus far kept convection from developing in our area, and this could continue right into Thursday, however, with a warm front and cold front expected to move across the Northland through Thursday, scattered showers and thunderstorms can't be ruled out...If storms do develop they could become strong to severe with damaging winds and possibly some hail.  Torrential rainfall and frequent cloud to ground lightning will also occur if storms do develop.

With the cap in place (Warm air aloft) it might prove very difficult for thunderstorms to develop in our area, or for them to survive very far into the Northland should storms fire up over North Dakota or Manitoba later today much like what happened last evening.