Showalter Index Calculator

Heavy Rain and Flash Flooding in the West; Heat Expands in the Central U.S.

Monsoonal moisture will produce showers and thunderstorms with heavy rain over parts of the Southwest, Great Basin, and Central Rockies through Monday. Flash flooding is possible, especially in and around burn scars and in areas of steep terrain. Heat will persist across the Central U.S. early this week, spreading into the Ohio Valley and Mid-Atlantic later this week. Read More >

Showalter Index

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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.

Heavy Rain and Flash Flooding in the West; Heat Expands in the Central U.S.

Showalter Index

by Tim Brice and Todd Hall

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