Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EST Mon Feb 19 2024 Valid 00Z Tue Feb 20 2024 - 00Z Thu Feb 22 2024 ...Heavy rain and heavy mountain snow in California are expected to become less intense... ...A moderate risk of excessive rainfall remains in effect along portions of coastal southern California into tonight... ...Warming trend expected to expand across the Great Plains and into the Great Lakes through midweek... The West Coast continues to be in the midst of an active weather pattern as the core of an energetic large-scale low pressure system pushes onshore today. Under this weather pattern, California remains under the impact of heavy precipitation. The northern portion of California will be one area of concern where additional heavy rainfall will lead to a slight risk of flash flooding into Tuesday. Another area of concern will be along portions of coastal southern California where more focused heavy rainfall forced by local terrain will keep a moderate risk of flash flooding in place through tonight. Meanwhile, heavy snow can be expected over the higher elevations. By Tuesday, the low pressure system is forecast to weaken. This will allow the coverage and intensity of the rain/snow to progressively decrease with time. Nevertheless, additional residual energy arriving from the Pacific will result in more rounds of light to moderate elevation-dependent rain/snow into Wednesday. Meanwhile, moisture from the weakening low pressure system will continue to push well into the Intermountain West, bringing additional rounds of rain/snow across the Great Basin and into the northern Rockies over the next couple of days before reaching into the central Rockies and toward the Four Corners by Wednesday. Meanwhile, much of the eastern two-thirds of the country will remain dry through the next couple of days under a slow-to-evolve weather pattern. A warming trend is expected to expand across the Great Plains through midweek where an upper ridge is forecast to build. High temperatures will be between 15-25 degrees above average by Wednesday over much of the central U.S. Dry conditions will extend into portions of the Four Corners region as well. By later on Wednesday, much of the energy associated with the upper-level trough moving through the western U.S. will begin to move into the central Plains where a new low pressure system is forecast to develop. Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php