National Weather Service United States Department of Commerce

Heat Wave and Severe Thunderstorms this Independence Day

A prolonged, dangerous heat wave will persist through the Independence Day weekend across the Ohio Valley, Midwest, and Mid-Atlantic. Numerous temperature records are expected. Clusters of severe thunderstorms will move across parts of the Allegheny Plateau into Mid Atlantic this Independence Day, with potential for widespread damaging winds. Additional severe thunderstorms in the Great Plains. 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)