Dan Robinson
EF5
I'm using the whitewater rafting class levels as a template for categorizing the risk of chase maneuvers. This is my first attempt at populating these classes. Feel free to add your input/revisions!
* high visibility/classic supercells
Class VI: Among all chasers who perform these maneuvers, there is an average of one accidental tornado impact every 2 seasons. High risk of death or injury even for experienced and adequately-equipped chasers.
- Entering the outer circulation of violent or wedge-sized tornadoes*
- Approaching violent rain-wrapped tornadoes
- Entering rain-filled RFD toward an area with an intense radar-indicated circulation and/or large, violent tornado reported
Class V: Average of one accidental tornado impact every 4 seasons. Requires absolute mastery of chasing execution and adequately-equipped vehicle.
- Approaching violent or wedge tornadoes within 100 yards of the outer circulation*
- Entering rain-filled RFD with reported tornado and/or strong radar-indicated circulation
- Positioning within the notch of HP supercells in extreme tornado environments
- Approaching strong rain-wrapped tornadoes
- Entering the outer circulation of strong tornadoes*
Class IV: Average of one accidental tornado impact every 6 seasons.
- Positioning under the meso in extreme tornado environments
- Positioning within the notch of HP supercells in strong tornado environments
- Approaching weak rain-wrapped tornadoes
Class III: Average of one accidental tornado impact every 10 seasons.
- Approaching strong tornadoes within 100 yards of the outer circulation*
- Approaching violent tornadoes within 1/4 mile*
- Positioning within the notch of HP supercells in moderate tornado environments
- Positioning under the meso in strong tornado environments
- Entering any rain-filled RFD toward a developing/developed meso
- Approaching/entering outer circulation of weak tornadoes*
Class II: Average of one accidental tornado impact every 12 seasons.
- Approaching strong tornadoes within 1/4 mile of the outer circulation*
- Approaching violent tornadoes within 1 mile*
- Positioning within the notch of HP supercells in weak tornado environments
- Positioning under the meso in weak tornado environments
- Crossing low-visiblity (rainy) RFD/hook slicing to gain visual of a meso/tornado
- Core punching from the north through the forward flank of a supercell
- Approaching strong tornadoes within 1/2 mile*
- Approaching outer circulation of weak tornadoes*
Class I: Average of one accidental tornado impact every 20 seasons.
- Positioning either behind or 90 degrees right of the track of supercells and tornadoes
- Positioning more than 5 miles ahead of supercells/tornadoes, never crossing their path
- Staying more than 2 miles from weak tornadoes
- Staying more than 5 miles from strong to violent tornadoes
* high visibility/classic supercells
Class VI: Among all chasers who perform these maneuvers, there is an average of one accidental tornado impact every 2 seasons. High risk of death or injury even for experienced and adequately-equipped chasers.
- Entering the outer circulation of violent or wedge-sized tornadoes*
- Approaching violent rain-wrapped tornadoes
- Entering rain-filled RFD toward an area with an intense radar-indicated circulation and/or large, violent tornado reported
Class V: Average of one accidental tornado impact every 4 seasons. Requires absolute mastery of chasing execution and adequately-equipped vehicle.
- Approaching violent or wedge tornadoes within 100 yards of the outer circulation*
- Entering rain-filled RFD with reported tornado and/or strong radar-indicated circulation
- Positioning within the notch of HP supercells in extreme tornado environments
- Approaching strong rain-wrapped tornadoes
- Entering the outer circulation of strong tornadoes*
Class IV: Average of one accidental tornado impact every 6 seasons.
- Positioning under the meso in extreme tornado environments
- Positioning within the notch of HP supercells in strong tornado environments
- Approaching weak rain-wrapped tornadoes
Class III: Average of one accidental tornado impact every 10 seasons.
- Approaching strong tornadoes within 100 yards of the outer circulation*
- Approaching violent tornadoes within 1/4 mile*
- Positioning within the notch of HP supercells in moderate tornado environments
- Positioning under the meso in strong tornado environments
- Entering any rain-filled RFD toward a developing/developed meso
- Approaching/entering outer circulation of weak tornadoes*
Class II: Average of one accidental tornado impact every 12 seasons.
- Approaching strong tornadoes within 1/4 mile of the outer circulation*
- Approaching violent tornadoes within 1 mile*
- Positioning within the notch of HP supercells in weak tornado environments
- Positioning under the meso in weak tornado environments
- Crossing low-visiblity (rainy) RFD/hook slicing to gain visual of a meso/tornado
- Core punching from the north through the forward flank of a supercell
- Approaching strong tornadoes within 1/2 mile*
- Approaching outer circulation of weak tornadoes*
Class I: Average of one accidental tornado impact every 20 seasons.
- Positioning either behind or 90 degrees right of the track of supercells and tornadoes
- Positioning more than 5 miles ahead of supercells/tornadoes, never crossing their path
- Staying more than 2 miles from weak tornadoes
- Staying more than 5 miles from strong to violent tornadoes
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