National Weather Service United States Department of Commerce

Severe Weather Threat Across the Central U.S.

Severe thunderstorms will be possible over portions of the Central Plains today. An Moderate Risk (level 4 of 5) has been issued for western and central Kansas. The main threats will be damaging wind gusts, large hail, and a few tornadoes. The severe weather threat continues across the Central U.S. over the next few days. Read More >

 

Clicking on the map will generate a Clearing Index table for the next 7 days for that location

      
   

 

 

 

Mouse over the images below to see better detail, or click for full scale view

 

 

 

 
The Clearing Index is an Air Quality/Smoke Dispersal Index used to regulate open burning and as input for other air quality decisions throughout Utah. The Clearing Index is defined as the Mixing Depth (depth of the mixed layer in 100s of feet above ground level) multiplied by the Transport Wind (average wind in the mixed layer in knots). Clearing Index values below 500 are considered poor ventilation and open burning is restricted under these conditions. Any Clearing Index values above 1000 are considered excellent ventilation and are referred to as 1000+. Data for the Clearing Index on these web pages are derived from several operational atmospheric computer models. The data will be reviewed and may be edited by NWS meteorologists before dissemination.
   
An example calculation of the Clearing Index:
Mixed Layer Depth = 10000 feet
Transport Wind = 8 knots
Clearing index = (10000/100 feet) X 8 knots = 800
   
Note: Clearing Index is 1000+ if measurable precipitation or cold front passage occurs.
   
Utah Smoke Management Program