Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 AM EST Sun Dec 19 2021 Valid 12Z Sun Dec 19 2021 - 12Z Tue Dec 21 2021 ...Snow across northern New England as well as showers/thunderstorms along the Eastern Seaboard will taper off later today as low pressure system moves off the East Coast... ...Unsettled weather lingers over the Pacific Northwest, the northern Rockies and into the northern High Plains... ...Low pressure system forms over the Gulf of Mexico and moves toward Florida by Tuesday morning... A low pressure system centered near the New England coast early this morning will continue to intensify as it slides quickly offshore. Snow across northern New England early this morning will gradually taper off during the day. Meanwhile, scattered showers and some thunderstorms further south along the Eastern Seaboard will linger a bit longer today but they will eventually slide off the coast behind a cold front by this evening. Fine weather with more seasonably cold temperatures will prevail across much of the central to eastern U.S. beginning on Monday when a high pressure system dominates the weather pattern. Meanwhile, unsettled weather is expected to continue across the Pacific Northwest as arctic air attempts to filter in from Canada while a low pressure system develops off the West Coast. A couple inches of coastal/lower elevation rain and more than a foot of heavy snow in the Cascades can be expected. The precipitation will be oriented near a stationary front across Oregon today. The front is forecast to move northward tonight into Monday as a cyclone continues to develop off the West Coast. This will spread the unsettled weather northward into Washington on Monday. In the mean time, some of the heavy snow will extend eastward into northern Idaho and Montana where an arctic front dips slowly across the area. An Alberta clipper moving quickly across the Canadian prairies will bring colder air into the northern Plains today. Snow associated with the cold front trailing from the clipper will be light across the upper Great Lakes later today followed by interior New England on Monday and into Tuesday morning. Elsewhere, rain chances are expected to increase across southern Texas today as a low pressure system is forecast to develop along a meandering front in the western Gulf of Mexico. The low is expected to track eastward toward Florida on Tuesday where showers and thunderstorms will be on the increase Monday night into Tuesday. Some of the showers will also brush the Gulf Coast from west to east as the low pressure system develops in the Gulf. Kong Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php