Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 235 AM EST Thu Feb 18 2016 Valid 12Z Thu Feb 18 2016 - 12Z Sat Feb 20 2016 ...Heavy rain along with higher elevation snow to impact the West Coast... ...Light snow showers expected for the Great Lakes and New England... A robust upper level low will be the primary driver during this active weather period for the West Coast the next few days. As the upper low moves over the West Coast toward the Intermountain West, a cold front will push across the Great Basin and northern Rockies. Widespread precipitation is expected throughout the western coastline in addition to the Intermountain West. The heaviest axis of precipitation for Thursday will concentrate along coastal California--most especially southern California which is will get continuous influx of subtropical moisture. The Sierra Nevada mountain range can also expect heavy snowfall on Thursday. In fact, the higher elevations across the Cascades, northern Rockies, and Great Basin will all receive snowfall on Thursday. By Thursday evening and into Friday morning, the cold front will move into the Great Plains and thus a decrease in precipitation coverage can be expected especially for southern California and the central Great Basin. However, another upper level low along with an accompanying surface front will approach the Pacific Northwest by Friday morning. Precipitation will continue throughout Friday for this region and the northern Rockies, which also includes higher elevation snow, as the surface front moves inland across the Intermountain West. Unlike the previous frontal system, most of the higher elevation snow will concentrate along the Oregon and Washington Cascades and northern Rockies. By Saturday morning, the front will move across the Plains and consequently precipitation amounts will decrease. The swift moving front associated with the widespread precipitation for the western portions of the U.S. will cross the Plains and approach the Great Lakes by the early hours of Friday. Light snow can be expected for the Upper Great Lakes for Friday morning. By Friday night and into Saturday morning, the surface low will move eastward toward the lower Great Lakes and light snow will spread across western New England. Fanning Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php