Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EST Fri Feb 02 2024 Valid 12Z Fri Feb 02 2024 - 12Z Sun Feb 04 2024 ...Unsettled weather for the West Friday as heavy snow continues for the Sierra and spreads into the Great Basin and Rockies... ...Widespread thunderstorms shift from the Southern Plains Friday to the Lower Mississippi Valley/Gulf Coast on Saturday... ...Mild temperatures persist across central portions of the country through this weekend... An upper-level trough and accompanying surface frontal system will push eastward through the Great Basin and Rockies Friday, expanding the coverage of mountain snow and a rain/snow mix for lower elevation valleys across the West. A secondary upper-level trough/area of low pressure off the Pacific Northwest will also keep weather unsettled along the West Coast. Heavy higher elevation snow is expected for many of the local mountain ranges across the West including in California, the Great Basin, and the Rockies, which will likely see at least a foot of new snow through Sunday morning. Precipitation will be much lighter for most lower elevations, and any snow that mixes in should lead to little to no accumulations. Some heavier showers will be possible along the northern California/southern Oregon coast where thunderstorms are expected. Precipitation chances should come down for a period through the day Saturday for California and the Great Basin as the system moves further to the east while heavy snow continues in the Northern/Central Rockies. However, the first wave of heavy precipitation associated with another Atmospheric River may begin to impact portions of California as early as Saturday night, and likely by Sunday morning. Gulf moisture will begin to flow northward over the Southern Plains in advance of the approaching upper-level trough/surface frontal system moving through the West Friday, with isolated shower and thunderstorms during the day becoming more widespread by Friday night. Some severe thunderstorms are possible for central Texas as cooling temperatures aloft with the approaching trough should lead to sufficient CAPE, along with expected strong windshear, for some more robust updrafts. The Storm Prediction Center has issued a Slight Risk (level 2/5) of severe thunderstorms mainly for the threat of large hail. An increasingly moist boundary layer as well as the expectation for an organized line of storms to push eastward may also lead to increased coverage of some heavier downpours and an isolated risk of flash flooding. Storm chances will continue eastward into the Lower Mississippi Valley on Saturday where a developing coastal low may help to locally enhance storm coverage/intensity, leading to a bit higher threat of heavier rain and flash flooding, with a Slight Risk of Excessive Rainfall (level 2/4) in effect. The progressive nature of the system will bring clearing conditions through the region late Saturday night as storm chances increase across the Southeast and Florida. An amplified upper-level ridge over the central/eastern U.S. will keep high temperatures mild and well above average Friday and Saturday, particularly for portions of the Plains and the Midwest. Forecast highs range from the 30s and 40s for the Northeast and the Great Lakes, the 40s and 50s for the Northern Plains and the Ohio Valley, the 50s and 60s for the Central Plains and Carolinas, and the 60s and 70s for the Southern Plains and Southeast. Highs will remain cooler than average to the west under the influence of the upper-level trough, with highs mainly in the 40s for the Great Basin, 50s for the Pacific Northwest and northern California, and 60s for the Desert Southwest and southern California. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php