[idvusers] A boulder floods bundle

A timely teachable moment for the vorticity unit in my weather analysis class.

http://weather.rsmas.miami.edu:8080/repository/entry/show/RSMAS-UM+Repository+for+atm-ocean+data+and+its+science/The+Mapes+IDV+collection/IDV+Bundles/Boulderflood_synoptics_all?entryid=2409b172-2b85-46c7-b824-05675de1d714


See also this annotated movie about the upper level vorticity precursors.
I tell the students every pixel has a circular flow decaying as 1/r, and 
through these flows the red and blue pixels advect each other.
http://weather.rsmas.miami.edu:8080/repository/metadata/view/Boulderflood_soliton_rel_abs_vort300.mov?element=1&entryid=78441aec-e696-48dd-8525-27e5658f9bdd&metadata.id=d908ac3b-be67-4412-97be-bb1597374301