SIOUX FALLS, S.D. (KELO) — Strong to severe thunderstorms have developed this afternoon in eastern and southeast KELOLAND.  These storms will continue to move north/northeast through the afternoon.  All modes of severe weather are possible. 

There is a Tornado warning for northeastern Lyon County, Minnesota, until 4:45 p.m. CDT Monday. This includes Marshall; seek shelter if in that area.

As of 3:45 p.m. CT, the line of thunderstorm activity extends from Roberts County to Sioux City, Iowa, stretching nearly 250 miles as the crow flies.

The more severe part of the storm is in northeastern South Dakota and moving into western Minnesota.

There is a severe thunderstorm warning for portions of Lincoln (MN), Lyon, Murray and Pipestone Counties until 4:30 p.m. CDT Monday. 70 mph gusts are possible with this line, moving northeast at 65 mph.

While things have quieted down in portions of southeastern South Dakota, we’re going to watch a cluster of storms in northeast Nebraska as it moves northeastward toward the Missouri River over the next hour or so.

There are a number of ways to receive weather alerts and updates from the KELOLAND Live Doppler HD Storm Center.  

Our Weather page includes the latest current conditions along with information on rainfall totals and wind speed.  

You can easily track the severe storms as they move toward your neighborhood using our KELOLAND Live Doppler Radars online.  

Our Storm Center page combines all of the online resources to follow the weather. 

You can also check the weather in dozens of towns across the area on our KELOLAND Live Camera page.

As you are on the go, make sure to check the KELOLAND News and KELOLAND StormTracker apps for updates.  Download the apps now so that you are prepared when storms hit. 

Observers reported seeing a tornado on the ground in the Rock County, Minnesota, area as of 3:22 p.m. CT.

A tornado warning for southwestern Robert and northwestern Grant Counties until 3:30 pm. Radar indicated rotation with this storm, moving north at 50 mph. This includes Marvin and Wilmot.

Tornado warning for eastern Brookings and western Lincoln (MN) Counties until 3:15 p.m. CDT Monday. Radar indicated rotation. This line is moving northeast at 60 mph.

A severe thunderstorm warning has been issued for portions of Lincoln, Lyon, and Minnehaha Counties until 3:15 p.m. CDT Monday. This storm is capable of producing large hail, moving northeast at 45 mph.

We are continuing to watch this storm southwest of Sioux Falls as it begins to move into a more favorable environment for severe development. Keep an eye out and an ear open if you’re in parts of Turner and Lincoln Counties.

Tornado warning for east-central Kingsbury, north-central Lake, and western Brookings Counties until 2:45 p.m. CDT Monday. This line is moving north at 45 mph. Radar indicated rotation.

Tornado warning for Moody County, eastern Lake County, and Northern Minnehaha County until 3 p.m. CDT Monday. Radar indicated rotation. This is moving northeast at 35 mph.

TORNADO WATCH is in effect for southeast KELOLAND through 6 p.m. CT  I wouldn’t be surprised if another watch will be issued farther to the north.  Stay weather aware throughout the day and have a way to get weather warnings. 

Most of the severe weather will be north of Interstate 90 by 5 p.m., but expect ongoing severe weather in eastern and northeast KELOLAND through the evening hours.   

During the evening, strong westerly winds will move into southeast KELOLAND with gusts over 50 mph.  These winds will bring in much cooler and drier air through the overnight.  Temperatures tonight will fall to the 40s and 50s for many locations. 

With the cooler air tomorrow, skies will be mostly cloudy with periods of sunshine.  An isolated shower or two will still be possible, but anything that falls and makes it to the ground will remain light. 

Wednesday will be very cool with highs only in the 60s, but we’ll slowly warm later in the week and for the weekend.   

Updated 7:30 a.m. CT

An outbreak of severe weather is forecast in eastern KELOLAND today. Storms are still ongoing this morning, adding to the complexity of the forecast for today. First, it is important to recognize the potential for a very dangerous forecast with the potential for several tornadoes in eastern SD, NW IA, and western MN during the daypart forecast. The severe weather will likely develop much earlier in the day, as early as noon. There even exists the potential for a couple of large, long-track tornadoes in our viewing area.

First, the maps this morning show a strong area of low pressure lifting northward into South Dakota. This will help trigger the expected rounds of severe weather in the forecast.

The most likely scenario depends on morning thunderstorms moving north and west of the James Valley before 9am, with partial clearing expected in much of southeastern KELOLAND. While severe weather is possible in central KELOLAND near the surface low track, most of the attention will be focuses on the highly volatile atmosphere farther east, specifically east of the James River Valley. All the ingredients for severe weather will be in place as early as 11am or noon.

This graphic below shows the needed information to tune in NOAA weather radio in your location. Please make sure you have a way to receive emergency severe weather alerts today.

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The main question is what mode of storms will be favored. If the storms take on more of a line or linear mode, hail and high winds may accompany a threat of a few tornadoes as the line develops in the zone bordered between Mitchell, Yankton, and Sioux Falls. This line will be move quickly to the northeast into western MN and adjacent areas of east-central and northeast SD. While this outcome would produce severe weather, it is the lesser to the two situations being considered.

The other school of thought focuses on the storms remaining discrete supercells for a longer period of time. If this second scenario develops, we will be facing a larger tornado outbreak, probably the largest in a few years for this area. As mentioned, this even opens the door to a couple of tornadoes developing and staying on the ground for many miles. These situations, while rare in KELOLAND, do occur and the Storm Prediction Center has already highlighted this possibility in the latest Day 1 outlook. Severe weather is expected and you should be monitoring the weather frequently through the day.

After the storms pass through, a period a very strong southwest winds with gusts to 50-60mph are possible in southern and southeastern SD. If you are towing a camper or driving a high profile vehicle late Monday afternoon or evening, we would advise being aware of this non-thunderstorm wind threat.

We will be updating the forecast frequently in the next 12 hours. Our KELOLAND Storm Center staff is ready and fully prepared to cover breaking weather in our Upper Midwest region.