Great Basin

The winds next week are expected to be influenced by an “inside slider” — a type of low-pressure system that is expected to move down from Canada into interior California and Nevada and bring wind from high pressure over the Great Basin, but not the rain that is desperately needed.

They occur when a large area of high pressure becomes established over the interior of western US, centred around the Great Basin, which includes much of Nevada and parts of Utah, Idaho and south-east Oregon.

A clockwise high-pressure system was parked over Northern California and the Great Basin as a counterclockwise low-pressure system hovered over Arizona.

The dry, strong Santa Ana winds are being driven by a system of high pressure building in the Great Basin, which is sending air hurtling through canyons and mountain passes to the coast, where there is low pressure.

Santa Ana winds form around this time of year when a system of high pressure builds in the Great Basin — over Nevada and Utah — and then seeks a release valve off the coast, where there is low pressure.