Scattered Strong to Severe Thunderstorms and Heavy Rainfall possible late this afternoon into tonight

Setup for today includes a warm front which will lift slowly north out of central Minnesota, this boundary combined with any leftover boundaries from this morning’s thunderstorm complex will help initiate another round of scattered thunderstorms over parts of the Northland late this afternoon, continuing into tonight.

Hazards through this evening include

-Large Hail to golf ball size

-Damaging Winds to 70 mph

-A tornado or two

-Dangerous Lightning

-Heavy Rainfall

Note: Tree and property damage may be possible. Dangerous conditions for outdoor recreation and camping.

Know the difference between a Watch and Warning – A Watch means conditions are favorable for severe weather, a watch usually covers a large area and lasts for ~6 hours, while a warning means severe weather is imminent, take shelter now! Warnings typically will cover a smaller area, and will last up to an hour.

A Slight Risk for Severe Thunderstorms covers all of northeast Minnesota and northwest Wisconsin through tonight, and the Tornado probabilities have increased as well in the latest update from the Storm Prediction Center (11:30 AM Wednesday)

There is now a 5% chance for a tornado for portions of north-central, east-central, and northeast Minnesota into far northwest Wisconsin (orange shaded area on map) 2% chance for a tornado in the areas shaded in green.

No shortage of moisture for storms today with dew points in the 60s and 70s across the upper Midwest.

One potential problem to get thunderstorms to develop may be the Elevated Mixed Layer or capping inversion which is in place today as hot/dry air heads NE out of the western High Plains. 700mb temps as of midday are up to +10C across southern portions of the Northland, with even warmer air farther south which will continue to advect northeastward into our area this afternoon. Note: The expectation is that the forcing with the warm front will be strong enough to erode the cap which will cause thunderstorms to develop in our area later this afternoon.

And finally there is a lot of potential energy in the atmosphere this afternoon with a large reservoir of high CAPE of >2000 J/kg lurking off to our southwest. The air mass across the Northland continues to destabilize this afternoon in wake of this morning’s thunderstorms, and with clearing and further heating ongoing as of 2 PM Wednesday, we should see higher amounts of CAPE begin to lift NE into the Northland. Note: Mid Level Lapse Rates are also impressive today in part due to the Elevated Mixed Layer with values of 7.0-8.0 C/km over much of the Northland, this raises some concern for possibly some large hail from a few of the storms that may develop late this afternoon or early this evening.

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Early Wednesday morning Derecho as seen on Goes-16 Sandwich Satellite loop starting ~12 AM Wednesday and ending ~7 AM Wednesday, July 8, 2020.

Source: https://weather.cod.edu/

And here’s a radar loop of Wednesday morning’s Derecho which affected parts of North Dakota and west-central Minnesota.

Loop time 12 AM to 7 AM Wednesday, July 8, 2020.

Widespread wind damage reports (blue dots on map) from Montana to west-central Minnesota from Tuesday evening through early Wednesday morning including 11 significant wind reports >65 knots (black squares on map)

Source: https://www.spc.noaa.gov/

Storm Reports from around the Northland from Wednesday morning, July 8, 2020

Source: https://www.weather.gov/dlh/

8:34 AM: Hail 0.25″. Hinckley, MN (Pine County)

8:16 AM: Thunderstorm Wind Gust 47 mph. 4 ENE Brook Park, MN (Pine County)

6:55 AM: Thunderstorm Wind Gust 43 mph. 3 W Woodrow, MN (Crow Wing County)

6:50 AM: THUNDERSTORM WIND DAMAGE. 3 N Brainerd, MN (Crow Wing County) Birch tree unknown diameter blown over.

6:40 AM: THUNDERSTORM WIND DAMAGE. 4 NW Casino, MN (Cass County) 6FT Glass Top Patio Table overturned.

6:35 AM: Heavy Rain 1.50″. 1 NNW Motley, MN (Cass County) Wind gust knocked over 2FT planters.

6:30 AM: THUNDERSTORM WIND DAMAGE. 4 E Pillager, MN (Cass County) About an 8 inch diameter oak tree was uprooted during gusty winds. Fell over and caused damage to nearby fence.

Rainfall Reports from Wednesday morning, July 8, 2020

Source: https://mesowest.utah.edu/

Brainerd, MN: 0.70″

Chisholm-Hibbing Airport: 0.57″

Moose Lake, MN: 0.50″

Hill City, MN: 0.48″

Orr, MN: 0.46″

Pine River, MN: 0.46″

Hinckley, MN: 0.44″

Bigfork, MN: 0.43″

Cass Lake, MN: 0.39″

Walker, MN: 0.34″

McGregor, MN: 0.26″

Saginaw, MN: 0.22″

Duluth Airport: 0.18″

Cook, MN: 0.16″

Minong, WI: 0.15″

Solon Springs, WI: 0.14″

Barnes, WI: 0.12″

Superior Airport: 0.10″

Littlefork, MN: 0.09″

Ely, MN: 0.07″

Hayward, WI: 0.05″

International Falls, MN: 0.02″

A look at Radar Estimated Rainfall Totals from this morning’s round of thunderstorms. Greatest amounts were found along a line roughly from Fargo to Brainerd, south to St. Cloud.

Thanks for reading!

Tim

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