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Snow North and West Through Sunday Morning. Freezing Drizzle, Light Snow and Fog South and East Tonight and Early Sunday. Much Colder with Heavier Snow Thursday.

Winter Weather Advisories for parts of east and south central WY through Sunday morning for snow and gusty winds. Freezing drizzle, light snow and fog tonight and early Sunday for southeast WY and western NE. A strong cold front will sweep across southeast WY and western NE late Wednesday into Thursday bringing the potential for heavier snow and travel impacts to the region. Read More >

Overview

One of the most significant severe weather outbreaks to impact southeast Wyoming and the western Nebraska Panhandle in the past 30 years occurred on the afternoon and evening of June 12, 2017.  A strong low pressure system moving across the northern Rockies on Monday triggered widespread severe thunderstorms across the area. The Storm Prediction Center (SPC) issued a moderate risk forecast for Monday. The Storm Prediction Center issued a particularly dangerous situation (PDS) tornado watch around 1:00 pm.  This is the first ever PDS tornado watch issued for Wyoming.

Throughout the afternoon several tornadoes touched down initially near Fort Laramie, WY and lifted northeast through north central Goshen County, and crossed the state line into Sioux County. Several homesteads were damaged with 2 minor injuries in this area. Another tornado touched down roughly 11 miles northeast of Cheyenne and produced only minor damage. Additional tornadoes formed across the extreme southeast corner of Wyoming and lifted northeast contributing to damage in northwest Kimball County and into Morrill and Box Butte Counties. Numerous homes were damaged with this tornado. The town of Bayard was an area hit the hardest with several homes near complete losses. These storms continued to move northeast until finally weakening later that night.

Forty warnings (24 Tornado and 16 Severe Thunderstorm) were issued. Twenty-two reports of tornadoes were received during the afternoon and evening. The False Alarm Rate for warnings issued was 34%, Probability of Detection for events warned was 94%, and the average lead time from warning issuance to beginning of the event was 22 minutes.

Radar GIF

Radar reflectivity of the storms that developed during the afternoon and early evening.

Supercells near Bushnell tornado north Cheyenne Kimball ne

A couple of supercell storms near Bushnell, NE

Credit: Jacob Deflitch

Tornado that formed north of Cheyenne

Credit: Chuck Patient

Supercell storm near Kimball, NE

Credit: Tyler Sanders

 

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