Severe Thunderstorms and Heavy Rainfall Across the Midwest into the Great Lakes Region; Significant Heat in the Southwest

Strong to severe storms may produce damaging winds, isolated hail, and a few tornadoes from the Midwest into the lower Great Lakes. These storms may also produce areas of heavy rain and flash flooding. Significant heat will continue across parts of the Desert Southwest into western Texas and north Alaska. Dangerous heat will also build into the Eastern and Central U.S. and continue into next week. 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.)