Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 257 AM EST Wed Jan 16 2019 Valid 12Z Wed Jan 16 2019 - 12Z Fri Jan 18 2019 ...Heavy precipitation returns to California... ...Arctic air surges south across the northern Plains... A major winter storm will hammer much of California through early Thursday as a deep surface low tracks towards the coast. An impressive surge of deep moisture ahead of the cold front through Wednesday night will produce widespread heavy rain across the lower elevations of the West Coast states, with 2 to 4 inches of rain likely for many areas. A broad slight risk area for excessive rainfall encompasses much of central California, and a moderate risk for the mountainous terrain near Los Angeles, along with the possibility of mud slides. Blizzard conidtions are expected for the higher elevations of the Sierra Nevada through early Thursday with the expectation of at least two feet of snow and winds in excess of 50 mph. Very heavy snow is also expected for the mountains of northern California and extending northward across the Cascades. As the storm system moves inland across the Intermountain West, numerous snow showers are expected from Nevada to western Colorado, and these could be heavy at times. Elsewhere, a strong cold front will surge southward across the Plains on Tuesday and into early Wednesday, bringing frigid temperatures to the Dakotas and the Upper Midwest by the middle part of the week. In fact, high temperatures will be nearly 15-20 degrees below normal. There should be enough moisture with this front to produce some mixed precipitation over the lower Great Lakes and snow showers behind the front over northern Michigan. With a large surface high over the Gulf Coast region, return flow from the Gulf of Mexico will bring an increase in moisture through eastern Texas and into the central Plains, where some showers are likely on Wednesday. Precipitation will spread north and east across the Mississippi Valley on Thursday as a front pushes eastward across the Mississippi Valley eastward into the Mid-Atlantic. Along the northern portions of the Great Lakes and Ohio Valley, expect snow and a wintry mix with this system from Thursday night and into Friday. Reinhart/Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php