Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 346 AM EDT Sat Apr 13 2024 Valid 12Z Sat Apr 13 2024 - 12Z Mon Apr 15 2024 ...Heavy lower elevation rain, mountain snow, and gusty winds forecast for California... ...Shower and thunderstorm chances from the Great Lakes into the Northeast this weekend, with a threat for some severe weather in the Upper Ohio Valley/central Appalachians Sunday... ...Well above average temperatures across the Interior West/central U.S. Saturday expand to the East Coast Sunday... A deep upper-level closed low and associated surface frontal system approaching the California coast this morning will be the dominant driver of hazardous weather for the country for at least the next several days. Pacific moisture flowing inland will bring moderate to locally heavy lower elevation coastal/valley rain showers and thunderstorms to portions of the Pacific Northwest and California Saturday. The heaviest rain totals are expected where the moist flow intersects favorable upslope regions along the central Coastal Ranges into the Transverse Ranges and northern/central Sierra, and some isolated instances of flooding could occur. Rainfall amounts overall should come down into the day Sunday as the system moves further inland and the influx of moisture from the ocean decreases. However, some locally heavy amounts are once again possible, particularly for the Transverse Ranges where wet antecedent conditions from the prior days rainfall will bring another risk of some isolated flooding. In addition to rainfall, higher elevations in the northern Coastal Ranges, Klamath Mountains, and Sierra Nevada will see some moderate snowfall accumulations, with Winter Weather Advisories in place. Much cooler air settling in following the passage of the cold front and with the deep upper-low overhead will even lead to some snow for higher elevations in the mountains around greater Los Angeles. Some light to moderate lower elevation rain showers and higher elevation snow will also spread into the Great Basin Saturday and northern Great Basin/Rockies Sunday. Otherwise, conditions in vicinity of the system will be rather dry as it pushes through the Rockies and into the Plains by Monday morning, with a renewed threat for more widespread showers and thunderstorms, including some severe weather, later Monday just beyond the current forecast period. Winds will also be rather gusty as the system passes through the West. Some lingering areas of light to moderate showers continue this morning across portions of the Great Lakes/Interior Northeast, rotating around a deep cyclone located in southeastern Canada. Some higher elevations of the Appalachians may see some snow mix in. Gusty winds will remain in place as well. Shower chances should taper off into the day as the cyclone moves away from the U.S. However, a clipper-like system dropping southeast from Canada will bring a renewed chance of moderate showers and thunderstorms Sunday to the Interior Northeast, Lower Great Lakes, Upper Ohio Valley, and central/northern Appalachians. A strengthening upper-level wind field will overlap enough surface moisture/buoyancy to lead to the threat of some severe thunderstorms, with a Slight Risk (level 2/5) from the Storm Prediction Center from eastern Ohio into central Pennsylvania. Damaging winds will be the main threat, though some large hail and a tornado or two will be possible as well. A broad area of high temperatures 10-20 degrees above average will expand from the Interior West/Plains into the eastern U.S. this weekend as an upper-level trough departs the East Coast. Some of the greatest anomalies will be over portions of the northern/central Plains on Saturday, where highs into the 80s are upwards of 20-30 degrees above average. A few near record-tying/breaking highs will be possible Sunday across parts of the central/southern Plains into the Middle Mississippi Valley as highs reach into the mid-80s to low 90s. The combination of warmer temperatures as well as dry antecedent conditions and gusty winds have prompted an Elevated Risk of Fire Weather (level 1/3) from the Storm Prediction Center for portions of the central/southern High Plains Saturday and Sunday. In contrast, highs will be cool and well below average in California Saturday, spreading into portions of the central Great Basin and Desert Southwest Sunday, as the Pacific system pushes inland. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php