National Weather Service United States Department of Commerce

Heat Builds in the West; Extremely Critical Fire Weather in the Northwest

A heat wave over the Southwest will intensify this week, peaking and expanding into the Intermountain West and northern High Plains this weekend. Critical to extremely critical fire weather conditions are forecast from the Northwest and the northern Great Basin this weekend. Particularly Dangerous Situation Red Flag Warnings have been issued. 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)