National Weather Service United States Department of Commerce

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

The image below is a 1000m resolution, "true color" image from the MODIS satellite valid today - 1 February 2012.  A couple interesting features noted on the image are described below:

  •  Areas in "brown" are predominantly void of snow.  As such - a vast majority of South Dakota is completely snow free!  Obviously, this is quite rare for the 1st of February.
  • The "brown ground" is able to absorb much more solar energy, which allows temperatures to warm. This is a major reason why temperatures have remained above normal. 
  • Residual areas of snowcover (white) are confined to the Black Hills region in western South Dakota and the Glacial Lakes region in northeastern South Dakota. 
  • A large section of Lake Oahe north of Pierre is free of ice (dark blue color).  Again, very rare for early February.