National Weather Service United States Department of Commerce

Flash Flooding Continuing Along the Gulf Coast; Dry Thunderstorms in the West

Excessive rainfall continues to produce life-threatening, locally catastrophic flash flooding along the central Gulf Coast. Isolated to scattered dry thunderstorms may cause lightning-ignited fires and erratic behavior due to gusty winds across parts Oregon, California, and the Great Basin into the weekend. Read More >

Dispersion Index Table

DISPERSION INDEX TABLE

 
Dispersion Index Interpretation
>100 Very Good (but may indirectly indicate hazardous conditions.)
60-100 Good (typical burning values)
41-60 Fair to Good (climatological afternoon values for most inland forests.)
21-40 Fair (stagnation if accompanied by persistent low wind speeds.)
13-20 Poor to Fair (stagnation, if persistent; better than average for nighttime.)
7-12 Poor (stagnant, but near average at nighttime.)
1-6 Very Poor (climatological nighttime value for most locations.)