National Weather Service United States Department of Commerce

Wildfire Danger Continues in Southern California

High pressure building into the Western U.S. will create strong offshore winds in southern California. Temperatures in this region are unseasonably hot, and conditions are dry. The combination of these strong winds and dry conditions will bring fire danger to portions of southern California. Red Flag Warnings are in effect here. Any new fires in this region could quickly grow out of control. Read More >

Showalter Index

by Tim Brice and Todd Hall
 
Enter the temperatures that you would like:
 
Enter the 500 millibar parcel temperature: °C Answers:
Enter the 500 millibar environmental temperature: °C

What does my answer mean?

Showalter Index greater than 0: Stable, but weak convection possible for SI = 1-2 if strong lifting is present.
Showalter Index between 0 and -3: Moderately unstable.
Showalter Index between -4 and -6: Very Unstable.
Showalter Index between less than -6: Extremely Unstable.

 

What is the formula for the Showatler Index?