National Weather Service United States Department of Commerce

Extreme Heat and Excessive Rainfall Today

Dangerous and extreme heat will remain across portions of the southern U.S. through the weekend. A heat wave over the Southwest U.S. will intensify this week, peaking and expanding into the Intermountain West and northern High Plains this weekend. Multiple rounds of thunderstorms will produce heavy to excessive rainfall with significant flash flooding across portions of southern New England. 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)