Update at 3:30 p.m. to add tornado watches.

The Storm Prediction Center has issued two tornado watches that cover all of Minnesota except the northeastern and southeastern corners.

Two tornado watches have been issued for Minnesota. Storm Prediction Center

This is a serious weather situation. Strong to severe storms are likely to develop rather quickly during the latter half of this afternoon. Tornadoes are possible. Widespread damaging winds, possibly in excess of 70 miles per hour, and scattered large hail are possible, especially in the watch area in central to southern Minnesota.

The latest indications are that most storms that form will track toward the northeast as the entire weather system moves eastward.

National Weather Service radar from Chanhassen will track the storms and indicate any warnings that are issued. Warnings are issued when severe weather has been confirmed or is indicated on radar. They can be issued for all or parts of counties

The atmospheric stage continues to be set for a significant round of strong to severe thunderstorms across Minnesota this afternoon and evening.

A deepening upper level low pressure center with an advancing speed maximum over South Dakota will cause significant divergence aloft over Minnesota this afternoon. That means that air flowing outward in the upper atmosphere must be replaced by rising air. That upward pull generally strengthens thunderstorms.

GFS model forecast of wind flow in the upper atmosphere at 4 p.m. Saturday. NOAA/College of DuPage

At the surface, a cold front riding eastward from the Dakotas will be the trigger for storms as we go through the heating of the afternoon.

Expect strong storms to develop first across northwestern Minnesota this afternoon and then build farther to the south as the whole storm system moves eastward.

The latest convective outlook from the Storm Prediction Center extends the Enhanced Risk area farther into northern Minnesota and covers nearly the entire state with a Slight Risk.

Risk areas for severe weather mainly Saturday afternoon and evening.

Initially, supercell storms are likely to produce large hail and possibly tornadoes within the Enhanced Risk Area. Then, as thunderstorms merge into squall lines farther east later in the day, the severe weather risk will change to one of mainly damaging straight-line winds.

At this time, it appears that storms will approach the metro area from the west-northwest by very late afternoon or early evening.

GFS model 3-hour precipitation ending at 7 p.m. Saturday. NOAA/College of DuPage

Storms should weaken as they advance into Wisconsin and lose both daytime heating and support aloft.

So, whether you are at a family barbecue or maybe a football game today, stay weather alert. And remember that the biggest risk to people outdoors during thunderstorms is from lightning.