Eta 5-hour forecast sounding at ELM, with the boundary motion, valid 17 UTC on the 6th.

Slide Links:

Speaker Notes:

The white line on this diagram is the boundary motion, as determined by the observed movement of the line of thunderstorms. The 0-3 km shear vector indicated on this pre-storm sounding is perpendicular to the boundary, indicating a favorable environment for storms to merge into a line. This slide also indicates that individual storms would tend to fall behind the fast-moving boundary, indicating strong front to rear storm relative flow, and a storm structure that was likely tilting up-shear (as in slide 10).