Calculating Bunker's ID Method

[Gene Capuli]

Greetings to all. I'm currently trying to calculate Bunker's ID on a gridded dataset format with isobaric winds e.g. ERA5 (not 'directly' thru hodo). Following Bunker's equation, I already have/determined the;

1. 0-6 km Mean Wind Vector
2. The Shear Vector from 0-500 m to 5.5-6 km
3. Deviation "D" set as 7.5 m s^-1

I would like to ask what the "k̂" (k hat) parameter stands for Bunker's method? Is it some kind of a vector or 'constant' that I missed out that requires cross product? Thanks.

Image reference: Predicting Supercell Motion Using a New Hodograph Technique

 

[gdlewen]

k̂ (k-hat) in this context is a unit vector pointing in the z-direction. (Assuming standard vector notation is being used.). You can assume it has magnitude = 1.

If you use python and install the MetPy package, they offer this function. If you want to do this yourself as a learning exercise (something I highly-recommend because I do it all the time) more power to you.

Ref: bunkers_storm_motion — MetPy 1.5