National Weather Service United States Department of Commerce

Treacherous Travel Conditions Expected Early In The Week

The interaction of an arctic air mass and moisture will set the stage for an expansive area of dangerous travel conditions early in the week. A zone of freezing rain and drizzle along with some sleet is very likely from parts of Texas to the Ohio and Tennessee Valleys. Meanwhile, heavy rain and flooding will remain in the forecast for a large portion of the Hawaiian Islands on Monday. Read More >

This page will be replaced with a new version on or about Feb 1, 2023. Email w-slc.webmaster@noaa.gov with any feedback.

 

 

 

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