Snowy weather pattern continues in the interior mountains ofnorthwestern U.S. and down into the Sierra Nevada as the next round ofenhanced rainfall reaches northwestern California and southwestern Oregonon Tuesday.Accumulating snowfall near the Canadian border of the Northern Plainsexpected to taper off early on Monday.Another coastal storm is forecast to bring new round of rain up theAtlantic coast from later Monday through Tuesday as some threat of heavyrain emerges along the central Gulf Coast.Much above average, Spring-like temperatures shifting from thePlains/Midwest into the Northeast as Critical Fire Weather threat persiststhrough tonight in the central/southern High Plains.As the main energy associated with the latest winter storm that impactedthe western U.S. moves off into the northern Plains, the intensity of thesnow and high winds along the Sierra Nevada as well as across theIntermountain West will gradually wane through Monday.  However,reinforcing upper-level energies arriving from the Pacific with keep theunstable cold air mass in place across a large section of the westernU.S., with frequent rounds of mountain snows continuing and reaching asfar east as the central Rockies through the next couple of days.  Fromlater on Monday into Tuesday, another influx of moisture from the nextPacific frontal system is expected to bring a renewed round of enhancedrainfall from northwestern California to southwestern Oregon where somelocally heavy rainfall may occur.  Some embedded thunderstorms could alsoreach farther north along the coast of the Pacific Northwest and northernCalifornia on Monday as added instability associated with a surface troughedges toward the coast.  The moisture will then penetrate inland, reachinginto the northern Rockies as a round of moderate to locally heavy mountainsnows on Tuesday.Meanwhile, an intensifying low pressure system is bringing a round ofaccumulating snowfall near the Canadian border of North Dakota with awintry mix farther east across northern Minnesota on Sunday.  Theprecipitation will taper off later tonight as the storm moves farther awayinto southern Canada.  To the south and east, the recent dry spell willinitially limit rainfall amounts along a wavy front trailing southwesttoward a developing low pressure system over the central High Plains. However, persistent southerly flow from the Gulf of Mexico will eventuallydirect moisture northward to expand an area of rain from the Midwest tothe Great Lakes later on Monday into Tuesday.  Meanwhile, an upper-leveldisturbance will begin to interact with the returning Gulf moisture tobring an emerging threat of heavy rain into the central Gulf Coast stateson Tuesday and especially by Tuesday evening.Along the East Coast, following a recent round of widespread enhancedrainfall, another coastal low pressure system is forecast to form alongthe stalled front and track up the Mid-Atlantic coast Monday into Tuesday. This relatively compact system is forecast to deliver another round ofenhanced rainfall up the Mid-Atlantic states Monday and Tuesday, reachinginto New England by Tuesday afternoon.  Across Florida, thunderstormchances are forecast to decrease as the lingering front weakens with timebut they will increase again later on Tuesday as the aforementionedupper-level disturbance begins to approach from the west.Widespread much above average, Spring-like high temperatures will persistacross the central/eastern U.S. into Monday. The greatest anomalies of25-35 degrees over the lower/mid-Missouri Valley northeastward into theupper Great Lakes on Sunday will shift into the Ohio Valley, lower GreatLakes, and interior Northeast on Monday.