Good evening! Here are your latest updates:
The region has gotten lucky and had a couple relatively dry days across at least the southern half of North Dakota, South Dakota, and Minnesota, but portions of North Dakota have gotten a significant amount of rain in the last 24 hours with some areas getting 2.5+” of rain.
Past 24 hour rainfall:
Saturday Evening:
Though the storms have moved out of the area for the time being the next chance of severe storms will come this evening once the energy from daytime heating reaches its peak. Storm chances will greatly increase in the area right around 7pm CDT. Model simulated radar shows a rapidly developing line of thunderstorms that are likely to be severe with the primary risk being strong winds, but there will also be pockets of large hail. There is also a good potential for isolated tornadoes to develop particularly in the south-central region of North Dakota as outlined in the region circled on the graphic below:
Model simulated low-level energy at 7pm:
This line of storms will move out of North Dakota between 12am-2am CDT eastward into northern Minnesota. The main portion of the storm could begin to cross the border of northern Minnesota ~11pm and continue to move through the northern part of Minnesota before it takes a dive into the southeast portion of Minnesota and western Wisconsin. Typically these systems follow the energy so here is a graphic of where the storm is most likely to move based on the low level energy gradient tomorrow morning:
With the line on Saturday evening there will be heavy downpours that could lead to flash flooding in the area. The majority of eastern North Dakota only needs 1.5-2″ of rain within a 3 hour period to cause flash flooding currently. These storms could give the majority of the region 0.5-1.5″ of rain with isolated regions of 2+” as it moves through. There will be plenty of moisture for some of these cells to cause flash flooding.
Sunday- Monday Evening:
The storms that will be moving through South Dakota, southern North Dakota, and Minnesota are all part of the same cluster of energy that will begin to push through South Dakota early Sunday afternoon. There will be the chance for a severe storm or two out of this system with the main risks being strong winds and large hail, but the major concern with this system will be flash flooding. The largest risks are in western South Dakota where these cells will be slower moving at first along with a corridor stretching from far eastern South Dakota through the majority of the southern half of Minnesota. The encircled regions below are at the greatest risk for flash flooding based on how much moisture will be available for these storms along with modeled precipitation amounts through the weekend, but southern portions of North Dakota and all of South Dakota are at risk for flash flooding Sunday and Monday:
Model simulated radar tonight through Monday afternoon:
Rain totals across the southern parts of North Dakota and the majority of South Dakota will range from 0.5-2″ with isolated pockets of 2.5+” of rain throughout the next couple days. Southern Minnesota will be worse off with both the Saturday system and the Sunday-Monday system moving through. The majority of the southern half of the state will see 1-2.5″ with several pockets of 3+” of rain possible.
Upper-level energy from Saturday evening – Monday evening (What sparks these storms):
Current Flash Flood guidance (how much rain we need in 3 hours to get flash flooding; With each round of rain we get these numbers will fall):
Modeled Amount of moisture in the region from tonight through Monday evening (Storms that develop in regions of purple or greater can get 1.5+ inches of rain within 3 hours):
As always if you have any questions or concerns don’t hesitate to reach out. Have a great rest of your weekend!