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Weather Calculator

by Tim Brice and Todd Hall

Showalter Index

Enter the temperatures that you would like:
Answers:
Enter the 500 millibar parcel temperature: ° C
Enter the 500 millibar environmental temperature: ° C
Formula for the Showalter Index Script
Back to the Weather Calculator

What does my answer mean?

Showalter Index greater than 0:
 The atmosphere is stable, but weak convection is possible for indices = 1-2 if strong lifting is present.
Showalter Index between 0 and -3:
 The atmosphere is moderately unstable.
Showalter Index between -4 and -6:
 The atmosphere is very unstable.
Showalter Index between less than -6:
 The atmosphere is extremely unstable.