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Summary

A line of strong to severe thunderstorms rapidly intensified in strength in the late afternoon of July 10, 2021 along the Mogollon Rim. Low level rotation associated with this line of storms formed around 4:50 PM MST and produced a tornado that lasted from 5:01 PM until 5:07 PM MST. The EF1 tornado left a 1.25 mile damage path oriented northeast to southwest between Happy Jack and Clints Well, Arizona. Damage was limited to intermittent areas of damaged or downed pine trees along the tornado track.

 

Timeline

 

Loop from 4:44 PM - 5:14 PM July 10, 2021 showing reflectivity (top) and base velocity (bottom) imagery over southeastern Coconino County where a tornado formed. The gray circles denote times with a notable velocity couplet and low-level storm rotation. The orange circles denote formation and termination of the strongest rotation couplet.

A tornado moved from northeast to southwest between Happy Jack, AZ and Clints Well, AZ in southeastern Coconino County in the late afternoon of July 10, 2021. The tornado track is estimated about a mile and a quarter in length through mainly rural forest.

 

 

• 4:44 PM - A line of showers and thunderstorms forming along an outflow boundary begins to move southward from the Little Colorado River valley and towards the Mogollon Rim.
• 4:50 PM - The outflow boundary from the LCR collides with the Mogollon Rim Convergence Zone boundary to rapidly create a line of strong to severe thunderstorms moving southwestward over the Mogollon Rim. Weak low level rotation begins to form.
• 4:56 PM - Rapid intensification of the line of severe thunderstorms continues and the velocity couplet further tightens to show temporal continuity in very low-level rotation.
• 5:01 PM - 5:07 PM - The tightened low level couplet is maximized with a tornado moving southwestward. The tornado created a damage path of about 1.25 miles in rural forest lands between Happy Jack and Clints Well, Arizona in this time period. 
• 5:14 PM - The tornado diminishes on the western side of Lake Mary Road as the velocity couplet weakens. 

• Intermittent areas of damaged and/or downed trees along an estimated 1.25 mile damage path. Multiple surveyed sites confirmed cyclonic (counterclockwise) rotation of the tornado, as shown on the base velocity imagery above, with trees laying southeastward on the left flank of the damage path and southwestward on the right flank.

Uprooted pine tree laying southeastward near the start of the damage path. Measured width of the roots was 140 inches.

Previously burned pine tree snapped at the base of the trunk

Pine tree snapped about halfway up the trunk with the top half of the tree laying southwestward.

Pine trees snapped in half and laying southeastward near the terminus of the damage path

For more information on impacts and general inquiries about this event, please reference the contacts below:

• National Weather Service:
  • Brian Klimowski, Meteorologist-in-Charge at brian.klimowski@noaa.gov
  • Tony Merriman, Warning Coordination Meteorologist at tony.merriman@noaa.gov

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