National Weather Service United States Department of Commerce

Severe Weather in the Central Plains; Heavy Rainfall in the Tennessee Valley; Critical Fire Weather in the West

Scattered severe storms capable of large to very large hail, severe wind gusts, and a few tornadoes will be possible across the central Plains this evening. Heavy to excessive rainfall may bring a flooding threat from the Great Lakes to the Mid-South through tonight. Hot, dry and windy conditions will continue to bring a critical fire weather threat from the Southwest into the Great Basin. Read More >

Smoke dispersal is categorized by using the Ventilation Rate. Ventilation Rate forecasts for a specific point can be found using the Fire Weather Dashboard. Click a spot on the map and scroll down to find daily and hourly Ventilation Rate values for the next few days.

 

Fire Weather Dashboard

 

The link above is configured to display smoke dispersal categories as shown here:

 

  Smoke Dispersal Vent. Rate, knot-feet (x1000)
     Excellent             150 or greater
     Very Good 100 to 149.99
     Good 60 to 99.99
     Fair 40 to 59.99
     Poor less than 40

 

Ventilation Rate = Transport Wind (kts) Mixing Height (ft)