/Issued 5:57 PM CDT, Saturday, August 25, 2018/
Radar loop ending at 6:40 PM CDT, Saturday, August 25, 2018.
A few thunderstorms moving E-NE across northwestern Minnesota late this afternoon.
Goes-16 Enhanced Infrared satellite loop from Saturday, August 25, 2018.
Loop time: 3:02 PM to 5:32 PM.
Scattered strong to severe thunderstorms have erupted late this afternoon mostly over southern Ontario Province down toward Angle Inlet and Baudette in extreme northern Minnesota. Note: Colder cloud tops show up in yellow and orange colors on this map.
18z HRRR model run
Simulated Radar Forecast valid from 10 PM this Saturday evening to 1 AM Monday morning. This model shows multiple waves of scattered strong to severe thunderstorms impacting parts of the Northland from late tonight through early Monday morning.
The entire Northland is under a Slight Risk of Severe Thunderstorms for Sunday and Sunday night. Stay Weather Aware!
12z European Ensemble model. 8-25-2018
Mostly cloudy to partly sunny skies across the Northland today with highs in the 70s, it was a little on the muggy side as well today with afternoon dew points running in the low to mid 60s. Surface map late this afternoon had a cold front stretching from northwest Minnesota to central South Dakota where it meets up with an area of low pressure over central South Dakota.
A cold front is forecast to move E-SE reaching a line from western Lake Superior to southwestern Minnesota by 7 AM Sunday — Scattered showers and thunderstorms are expected to develop near this boundary tonight, mostly impacting far northern Minnesota, although model guidance has been showing additional development occurring early Sunday morning farther south near the Brainerd Lakes and I-94 corridor in central Minnesota. The environment for these storms will have CAPE of 500-1500 J/kg along with steep mid level lapse rates of 7.0 to around 8.0 c/km and about 30 to 40 knots of deep layer wind shear, these parameters are favorable for a few strong to severe thunderstorms tonight with hail and strong winds being the primary threats. Lows tonight under partly to mostly cloudy skies will range from the mid 50s to mid 60s.
There will be little movement to a cold front which is forecast to extend from western Lake Superior to southwest Minnesota Sunday morning, this boundary will probably lift a bit to the north through the day before it shifts east as a cold front Monday morning. The potential is there for a few rounds of scattered strong to severe thunderstorms in northeast Minnesota and northwest Wisconsin Sunday and Sunday night. There will be favorable amounts of instability, moisture and wind shear present for severe weather on Sunday with hail and strong winds being the main risks the way it looks now. Highs Sunday will mainly be in the 70s, but if storms are more widespread, then highs could end up a little cooler.
Note: There will also be a threat for heavy rainfall with the thunderstorms tonight and Sunday with PWATS reaching 1.50 to 1.80″ at times. Flooding probably won’t be a big concern through Sunday, however, due to the recent period of dry weather that has occurred in most of the Northland, but if storms start to move over the same location for a few hours, that would increase the risk for flash flooding.
Trends in the computer models is to shift the cold front farther south with it stretching from southern Minnesota to northern Wisconsin on Monday — If this ends up happening, then the greatest potential for additional rounds of showers and thunderstorms, heavy rainfall and strong to severe thunderstorms would be from the southern half of Minnesota into central/northern Wisconsin with only a few showers possible in northeast Minnesota for Monday. Highs Monday are forecast to range from the lower 70s to lower 80s.
Note: Much cooler temperatures are expected for Tuesday with highs only in the 50s and 60s! This cool down will be brief as warmer air returns again for mid to late next week along with more chances for scattered showers and thunderstorms from Thursday through the Labor Day weekend the way it looks now. The pattern that is developing late next week and through the holiday weekend should have many dry hours, but will also run the risk for getting hit by some showers and thunderstorms at times, it’s impossible to predict what day/s hold the greatest chance for rain this far out in time so stay tuned to later forecasts over the next few days.
Duluth, Minnesota Climate Normals for August 26
Sunrise Sunday: 6:21 AM CDT
Sunset Sunday: 7:59 PM CDT