National Weather Service United States Department of Commerce

Severe Thunderstorms and Heavy Rain from the Plains to the Mid-Atlantic; Ongoing Heat in the South

Severe thunderstorms and showers pose a risk for excessive rain, localized flash flooding, strong gusts and/or large hail across portions of the northern and central Plains, the Lower Missouri to Lower Ohio Valleys, and across the Mid-Atlantic this afternoon and evening. Extreme heat is ongoing over the Desert Southwest and the Southeast U.S.. 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)