11:45 a.m. UPDATE
The Storm Prediction Center has shoved the slight and enhanced risk areas for severe weather to the north, now placing the Twin Cities in a slight risk and much more of southern Minnesota in an enhanced risk.
Damaging winds up to about 75 mph will be possible with the line of storms that, as of 11:45 a.m., located along a line from Benson to Marshall and moving east-southeast. A wind gust of 78 mph was measured in Benson, according to the weather service.
8:30 a.m. original story
A line of strong to severe storms pushing through northern South Dakota Thursday morning is expected to ride a boundary east-southeast through southern Minnesota and pose a threat for torrential rains and damaging winds.
But just how the storm system evolves as it arrives and blasts through southern Minnesota remains a bit of a mystery. The National Weather Service (NWS Twin Cities) believes there are three scenarios that could unfold.
- "A strong, lengthy bow echo, capable of producing large hail and possible widespread damaging winds, plows through."
- "A more compact bow echo; still be capable of producing wind and hail, though likely not as widespread."
- "An area/cluster of scattered showers and strong thunderstorms."
A severe thunderstorm watch is already in place across southwestern Minnesota until 3 p.m., where scattered severe winds up to 75 mph are possible.
The HRRR computer model would suggest a smaller-scale bow echo that packs a significant punch in far southern Minnesota and northern Iowa.
The NAM computer model projects a strong, lengthy bow echo (scenario 1).
Both solutions show the most severe impacts in far southern Minnesota and northern Iowa, though this is a developing storm situation that will require monitoring as the day progresses.
In terms of timing, it's likely that the storms will move into western Minnesota by midday and then strengthen as they slide across south-central Minnesota and continue moving into a potentially favorable environment for damaging winds, large hail and possibly a tornado or two, the weather service says.
One way or another, it's going to rain a lot in the southern half of Minnesota now through Saturday. The NWS is forecast upwards of 4 inches of rain in some areas, also updating its forecast to call for 2-4 inches in the Twin Cities over the next 48 hours.
After the morning/midday storms plow through Minnesota, there could be a short break before more showers and storms move through. Storms that develop Friday could be severe, namely across southeastern Minnesota.
Minnesota gets a short break Saturday before another chance of severe storms arrives Sunday. In fact, the Storm Prediction Center (SPC) already has a slice of the state, including the Twin Cities, in a slight risk for severe weather on Sunday.
It'll be a day worth monitoring as the SPC is suggesting potential for large hail, damaging winds and tornadoes.