Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 AM EDT Fri Apr 12 2024 Valid 12Z Fri Apr 12 2024 - 12Z Sun Apr 14 2024 ...Powerful low pressure system to produce gusty winds and heavy rain across parts of the Great Lakes, Ohio Valley, and Northeast through Friday... ...Lower elevation rain and mountain snow to enter California on Saturday... ...Well above average temperatures forecast to surge into the northern/central Plains this weekend... A broad area of showers and thunderstorms across the Midwest and into the Northeast will continue Friday as a deep cyclone over the Great Lakes slowly shifts into Canada. Showers should taper off from west to east across the Great Lakes/Ohio Valley as the low departs, with more moderate to heavy rainfall most likely along the Appalachians into the Lower Great Lakes. The heaviest rainfall is expected ahead of a trailing cold front through New England where an influx of moist southeasterly flow off the Atlantic along upslope portions of the northern Appalachians contributes to some more potent storms and rain totals. A Slight Risk of Excessive Rainfall (level 2/4) has been issued for portions of New Hampshire and Maine along and ahead of the White Mountains where the combination of heavy rain and snowmelt could lead to some instances of flooding. Some lighter lingering showers will last into Saturday, particularly for interior portions of the Northeast. Conditions will also remain breezy across the region with Wind Advisories in place for portions of the Great Lakes, Appalachians, and New England. In the West, some light lower elevation rain showers and higher elevation/mountain snow showers will be possible along a frontal system pushing southward through portions of the northern Great Basin and Pacific Northwest Friday. An approaching Pacific system will bring higher precipitation chances spreading southward into California later Friday and into the day Saturday. Some moderate to locally heavy showers will be possible along the coast, with accumulating snowfall expected for the Northern Coastal Ranges, Klamath Mountains, and Sierra Nevada. A Winter Weather Advisory has been issued for southern portions of the Sierra where 6-12 inches of snow is forecast. Gusty winds are expected here as well, especially along the area mountain ranges. Cooler, below average temperatures will spread eastward from the Lower Great Lakes/Ohio Valley/Tennessee Valley Friday into the Northeast/Mid-Atlantic Saturday following recent cold front passage. Highs will tend to be at or just below average further south into the Southeast and Florida. A broad area of much above average temperatures across the West/Plains Friday will expand into the Mississippi Valley Saturday as upper-level ridging shifts eastward over the central U.S. The greatest anomalies will reside over the northern and central Plains Saturday, where highs into the 80s are upwards of 20-25 degrees above normal. Much cooler temperatures will arrive in California Saturday as the Pacific system begins to move inland. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php