National Weather Service United States Department of Commerce

Thunderstorms in the North Central U.S.; Dangerous Heat in Texas

There is a severe weather and isolated flooding threat from the Central to Northern Plains tonight into early Thursday. The severe weather threat will progress eastward to the Upper Mississippi Valley/Great Lakes into the Lower Ohio Valley Thursday. Major to extreme heat will continue to impact much of southern Texas into next week, where widespread record-breaking temperatures are possible. 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)