Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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103 FXUS01 KWBC 221818 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 118 PM EST Fri Nov 22 2024 Valid 00Z Sat Nov 23 2024 - 00Z Mon Nov 25 2024 ...Very strong Atmospheric River is starting to press south producing one last round of heavy rain/mountain snows and strong wind gusts across portions of central California into tonight... ...Moderate to heavy snow for portions of the Central Appalachians today; while lighter snows linger across Northeast Interior New England through Saturday night... ...Elevated Fire Weather conditions exist across northern Peninsular Florida today... ...Some possible Frost/Freeze conditions across the South tonight... ...Above average temperatures expand across the Central U.S. this weekend... Regional RADAR mosaic and GOES Satellite suite show the second strong surface cyclone lifting north off the Pacific Northwest coast. Stronger flow aloft has allowed the cold front to finally make an onshore push and direct the anomalously strong Atmospheric River to direct away from saturated/flooded areas of Northern California providing beneficial rainfall across Central California into the Central Sierra Nevada range where it will continue to produce heavy mountain snows tonight into very early morning Saturday. Multiple feet of snow is likely to accumulate generally at or above 7000`. Very strong/gusty winds will slowly diminish through the rest of the day today, behind the front into the Pacific Northwest. Given saturated grounds, tree-falls remain possible and may result in additional power outages. Onshore flow will continue through the weekend with scattered lighter showers, mountain snows (reducing in elevation with cold air filtering in) and reducing winds. A very strong core of an upper-level closed low over the Northeast has supported a strong surface low with enhanced winds as it is swinging back around from Upstate New York through Northeast PA before transferring to a developing surface near Georges Bank toward Nova Scotia. The strength of the winds and wrapped around moisture is also enhancing upslope flow out of the Ohio Valley providing another opportunity for moderate to heavy snows across the Central Appalachians for a few more hours as the storm moves away. Additional 5-9" snow is accompanied by high winds that a Blizzard Warning is in effect until 6pm this evening for portions of eastern WV. Winter storm warnings and advisories extend into portions of central and northeast PA and southern and southeast Upstate NY through the evening as well. By the weekend, the secondary low near Nova Scotia will take full control and generally stall, throwing moisture and change for light lingering snow and rain showers through Interior northeast New England through the weekend. Along the periphery of this storm, strong winds and dry conditions have resulted in an area of Elevated Fire Weather (level 1 of 3) to be issued across the northern neck of Peninsular Florida for the remainder of the day. Also, behind the front, the higher winds are bringing sufficiently cold air south that weather service offices in Mississippi and Alabama to issue Frost and Freeze Warnings. With the Atmospheric River and stronger westerly flow aloft across the Rockies, will bring downsloping winds and broad return flow around the High Pressure across the Southeast/Northeast Gulf of Mexico by the weekend. This will bring solid warming across the Southern and Central Plains through the weekend with High temperatures in the 70s and 80s in the south and 50s and 60s across the the Lower Missouri River and Western Midwest states...generally 5-15 degrees above normal. A record or two may be broken. Though another surge of colder Arctic air is starting to nose into the High Plains of N MT by Sunday (20-30 degrees below normal). Gallina Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$