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Arctic Front Slides Southward; Heavy Rainfall Potential Across the South and for Hawaii

An arctic front will slowly drift southward this weekend. This will focus snow, locally heavy, from the Intermountain West, Rockies, Plains, and Great Lakes and eventually into the Northeast. Dangerously cold wind chills behind this arctic front are forecast for most of the Plains this weekend. Moisture will increase across the Gulf Coast and the State of Hawaii where flooding concerns increase. Read More >

Overview

An active weather system over the Great Basin brought conditions conducive for severe weather over northern and eastern portions of Wyoming on Monday, June 12th. Heat, moisture and wind shear was greatest in these areas. Storms initially formed near Casper, WY around 12:30pm, moving NNW into southern Johnson County. These storms gradually turned into supercells by 3:00 – 4:00pm, with other convection starting to form in the Big Horn Basin.  The first tornadic storm developed around 5:00pm over SW Johnson County, near Barnum. 1” to 1.75” hail was reported near Barnum by 5:15pm, increasing to 2.5” by 5:30pm 5 miles SW of Kaycee. This storm then proceeded to produce multiple vortices, as it neared Kaycee and Mayoworth. Reports of tornadoes came in between 5:35 and 5:50pm, as the storm slowly moved to the NNE.  

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