Heavy Rainfall and Snowfall Heading For the Southwestern U.S. (credit: NWS Reno, Nevada)

DISCUSSION: As the next round of deep Pacific moisture comes on board into many parts of the western and southwestern United States, there will be a very prolific precipitation event on tap for the next 24 to 48 hours.  As noted in the detailed forecast graphic attached above (courtesy of forecasters from the National Weather Service office located in Reno, Nevada), there will be impressive rainfall and snowfall totals found across eastern California as well as parts of western Nevada.  The majority of the heaviest snowfall will unfold as a direct result of there being a perfect set up for orographic (or terrain-based) enhancement of localized precipitation intensity.  This process occurs due to air parcels being forced to ascend more quickly over steeper-sloped surfaces such as hills and/or mountainsides.  As this occurs, a maximum amount of overall moisture is extracted from the given air parcel which produces locally heavier precipitation.  

In the case of the western and southwestern United States, this often occurs (and will also occur in this particular case) in the form of heavier valley rainfall as well as heavier mountain snowfall.  During this upcoming winter storm, forecasters are anticipating to see heavy snow and strong winds at upper elevations.  This nasty combination will create whiteout conditions and substantially increase regional avalanche hazards. Winds will also be very strong at times with Sierra ridge winds in excess of 150 mph possible.  Thus, the overall travel conditions will be extremely dangerous, if not impossible at times so be sure to remain on the side of caution if you get caught in an area getting hit hard by this upcoming winter blast.

To learn more about other high-impact weather events occurring across North America, be sure to click here!

​©2017 Meteorologist Jordan Rabinowitz