More rounds of excessive rainfall and severe weather expected to pusheastward across the southern Plains tonight reaching into lowerMississippi Valley on Monday......Snow over central Colorado gradually tapers off tonight buthigh-elevation snow is forecast to spread inland from the PacificNorthwest into the northern Rockies on Monday......Critical Fire Weather Risk over portions of the Southern High Plains......Warmer than average temperatures spreads from Midwest into Mid-Atlanticon Sunday while well below average temperatures shift from the FourCorners and Rockies into the Northern Plains...More active and unsettled weather is forecast to continue across themid-section of the country through the remainder of the weekend intoMonday.  Multiple disturbances embedded within a slow-moving upper-leveltrough responsible for the active weather are currently developing anotherlow pressure system over the central Plains.  Showers and thunderstormsare expected to erupt in the warm and unstable air ahead of the lowpressure system east of a dry line from northern Texas through centralOklahoma into eastern Kansas.  A moderate risk of severe weather isforecast through tonight per the Storm Prediction Center with thepossibility of large hail, damaging winds and multiple tornadoes.  Inaddition to the severe weather, intense rainfall rates are expected toaccompany these thunderstorms at times, leading to a moderate to locallyhigh potential of flash flooding to occur in these areas through tonight. By Sunday, the main area of thunderstorms will push farther eastwardtoward the mid- and lower Mississippi Valley with a slightly lower threatof severe weather.  Meanwhile, the heaviest rains should push farthersoutheast into the ArkLaTex region as the trailing cold front associatedwith the low pressure system begins to weaken.  The center of the low isforecast to track northeast across the central Plains on Sunday, reachinginto the upper Midwest on Monday.  Strong to locally severe thunderstormscan be expected to extend northeast across these areas including theMidwest ahead of a warm front to the east of the low pressure center. Meanwhile, the threat of heavy rain will push farther southeast into thelower to mid-Mississippi Valley as the cold front pushes eastward.Meanwhile, snow on the backside of the low pressure system is forecast togradually taper off tonight over central Colorado, and so will the areasof mixed rain/snow extending into the Four-Corners as the system movesfarther away into the central Plains.  Meanwhile, another low pressuresystem will begin to move away from the Great Lakes into Canada withscattered showers ending over the upper Great Lakes but continuing fromthe lower Great Lakes into New England.  Strong southerly flow behind ahigh pressure system will bring very warm air northward into the EastCoast through the next couple of days with high temperatures climbing wellinto the 80s to possibly near 90 degrees for the interior Mid-Atlantic. These temperatures will be in contrast to the cool temperatures expectedfor the Pacific Northwest by Monday as the next upper-level trough fromthe Pacific is forecast to push inland.  This trough will bring widespreadhigh-elevation snow and lower elevation rain across the Pacific Northwesttoward the northern Rockies on Monday with increasingly windy conditionsas a low pressure system begins to develop over the northern High Plainsinto southern Canada.  Meanwhile, dry and warm winds sinking down thesouthern Rockies will continue to keep a critical fire weather risk overthe southern High Plains.