Saturday (July 15th, 2017)

Overview

The upper level high bringing hot temperatures to the area today (Friday) will push east over the weekend, allowing an increasing chance of showers and thunderstorms Saturday and Sunday, several of which could be strong to severe.

Timing

West of I-15: Thunderstorms will begin developing by mid-afternoon, possibly a bit earlier in the mountains, pushing east by the evening hours. A few thunderstorms may linger across SW MT later into the night.

East of I-15: Thunderstorms will begin developing by late-afternoon, pushing east through late-evening. Thunderstorms may linger later into the night from Lewistown to Bozeman.

Sunday: Thunderstorms look to be more confined along and south of a Dillon to Lewistown line.

 

Potential Impacts

  1. Strong wind gusts of 50 - 70 mph
  1. Hail (half inch to quarter-size)
  1. Frequent lightning
  1. Increasing fire weather concerns from gusty winds and lightning associated with thunderstorm activity

Confidence

  1. At least a few thunderstorms producing 50-70 mph thunderstorm wind gusts = HIGH (Saturday), MODERATE (Sunday)
  1. At least one or two storms producing penny or greater size hail = MODERATE (Saturday), but LOW (Sunday)
  1. Frequent lightning = HIGH
  1. Fire starts from lightning  = MODERATE

 

Please monitor our web site for the latest updates at http://www.weather.gov/tfx/ 

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