Dynamically-Driven
Chinook Winds
qWhen the cross-mountain flow near the mountain-top is strong and an inversion is present upstream just above the mountaintop, the mountain wave pattern will take a form called “hydraulic jump”.
qAir passing over the mountain between the inversion level and mountaintop accelerates downslope in a shooting flow toward the base of the mountain.
streamfunction
qThe strongest winds in downslope windstorms occur as the
shooting flow reaches the
mountain base.
qNear or just beyond the mountain base, the flow abruptly rises
to produce the “hydraulic
jump”.
qChanges in the upstream wind sped and the height and strength
of the inversion influence
the character of a downslope windstorm.