Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EST Sun Jan 21 2024 Valid 12Z Sun Jan 21 2024 - 12Z Tue Jan 23 2024 ...Heavy precipitation moving across California today and again on Monday... ...Heavy rain expected to develop over southern Texas later today, shifting east into eastern Texas and Louisiana on Monday... ...Freezing rain and sleet to impact Oklahoma and Kansas this evening, spreading into the Midwest on Monday, following by wet snow across the upper Midwest and into the Great Lakes by Tuesday morning... Sunday morning will begin with a deep freeze engulfing much of the eastern two-thirds of the country under the dominance of a large dome of arctic air pressure. Sub-freezing temperatures will reach as far south as central Texas and northern Florida while sub-zero temperatures will be found across the upper Midwest. The expansive area of high pressure will then slide eastward to reach the East Coast on Monday. With no additional replenishment of arctic air from Canada, a steady warm-up is in store for the mid-section of the country. Deep return flow behind the high pressure system will begin to set up a channel of moisture from the Gulf of Mexico into the southern Plains later today into Monday. The chance of heavy rain is expected to increase quickly across southern Texas this evening and continue into Monday. Meanwhile, the presence of arctic air farther north will support mixed precipitation, sleet and ice as the moisture reaches into Oklahoma and Kansas tonight. The moisture will continue to surge northeastward into the Midwest on Monday, overrunning the arctic air and resulting in freezing rain/sleet. By Monday night into early Tuesday, an upper-level trough exiting the southern Rockies will interact with a front to bring an expanding area of snow into the upper Midwest into lower Michigan toward the lower Great Lakes. Meanwhile, lake-effect snow this morning downwind from the Great Lakes will gradually taper off later today, as will the upslope snow over portions of the central Appalachians. Along the West Coast, multiple frontal systems arriving from the Pacific will bring more active weather onshore through the next couple of days. Heavy rain will likely continue across northern California today, followed by a brief lull this evening before the next surge of heavy rain expected to arrive on Monday. Meanwhile, heavy wet snow is expected along the Sierra Nevada during similar time frame. In addition, the influx of warmer air overrunning the trapped cold air near the ground will continue to bring the potential of ice/freezing rain for the Columbia Gorge for the next couple of days. Mixed precipitation will begin to penetrate further inland across the Four Corners by Monday night into Tuesday morning with the passage of an upper-level trough as precipitation tapers off in California. Unsettled weather will also continue along the coast of the Pacific Northwest. Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php