Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 352 AM EDT Fri Apr 6 2018 Valid 12Z Fri Apr 6 2018 - 12Z Sun Apr 8 2018 ...Heavy rain expected for the West Coast and parts of the Deep South through Saturday... A developing storm system over the southern plains on Friday is expected to cause a variety of weather impacts to the south-central U.S. to close out the week. An impressive cold front for this time of year is ushering in an arctic air mass from Canada, and this boundary will intercept deep moisture from the Gulf of Mexico. Heavy rain capable of producing flooding and severe weather are both expected from the ArkLaTex region to western Alabama on Friday ahead of the front. Rainfall amounts of 1 to 3 inches, locally higher, are likely in this area by Saturday morning. The southeast U.S. and Virginia will be affected by this same storm system going into Saturday as it rapidly tracks eastward. The severe weather parameters will be a little less favorable for the southeast coast, but there should be enough shear and instability to support some strong to severe storms from the Florida Panhandle to the Outer Banks of North Carolina. Moderate to heavy rainfall is expected across much of Virginia and North Carolina, with some snow possible for the central Appalachians. For the West Coast, an atmospheric river will bring copious rainfall to the northern half of California and southwest Oregon through Saturday morning, with the potential for several inches of rainfall in some areas. Given the warm nature of this event, snow levels will be unusually high and even most of the higher Sierra mountains will get rain Friday and Friday night, before transitioning to snow showers later on Saturday behind a cold front. Significant rainfall is also expected across much of Nevada and the Great Basin as the moisture streams inland. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php