Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 AM EST Thu Dec 03 2015 Valid 12Z Thu Dec 03 2015 - 12Z Sat Dec 05 2015 ...Pacific storm system to bring heavy snow and possible freezing rain to the higher elevations of the northwestern U.S... ...Heavy snow possible for portions of northern Maine... ...Slow-moving frontal boundary expected to bring heavy rain to portions of South Florida... Much of the Pacific northwest will have widespread, mixed precipitation as a frontal system pushes through Washington and Oregon today. Rain is expected for areas west of the coastal ranges. For areas to the east, a mix of rain, freezing rain and snow will possible and likely dependent on elevation. Mountains snow and valley rain will increase as the front advances through the Rockies and into the High Plains on Friday. Most of Washington and north-central Oregon have warnings and advisories in effect for this winter storm system. Heavy snow is expected for the Cascades in association with this system, with 1 to 2 feet of snow possible. Additionally, freezing rain amounts of a tenth to a quarter inch are possible in passes and areas prone to cold easterly winds. Farther south in the Sierra Range, 4 to 15 inches of snow is forecast. Snowfall amounts of 4 to 8 inches will be possible for portions of the Northern and Central Rockies. An additional round of showers will be possible for the Pacific Northwest by early next week as another low pressure system approaching the region. Cold air will spill into the Northeast today as a low pressure center and associated front passing through. Rain over this region will likely transition to a wintry mix by this afternoon from portions of the central Appalachians into interior New England. The surface low offshore will strengthen as it is invigorated by an approaching upper-level disturbance, which will result in the precipitation changing to all snow across northern New England. Heavy snow will be possible at times, with 5 to 10 inches of snow possible for northern portions of Maine. Snow is expected to taper off by Friday morning. Winter storm warnings and winter weather advisories are in effect for northern Maine with this system. The trailing cold front associated with the low pressure system across the Northeast will cross the Florida Peninsula tonight, and will move into South Florida today. Numerous showers and thunderstorms will develop along and ahead of this boundary. The boundary will stall near the Florida Keys on Friday which will focus numerous showers and thunderstorms over South Florida. Impressive moisture flowing into this system will result in the potential for heavy rainfall. 2 to 4 inches of rain, with locally higher amounts, are possible across South Florida through Friday. An Excessive Rainfall Outlook issued by WPC highlights the potential for heavy rain for this area. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php