Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
237 AM EST Mon Dec 18 2023

Valid 12Z Mon Dec 18 2023 - 12Z Wed Dec 20 2023

...There is a Slight Risk of excessive rainfall over parts of Northern New
England on Monday...

...Lake-effect snow downwind of the Great Lakes and upslope snow over
parts of the Northern/Central Appalachians...

...Rain for most of the West Coast...

A deep storm over the Mid-Atlantic Coast will move northward into Eastern
Canada by Monday evening. The system will produce heavy rain over parts of
the northern Mid-Atlantic Coast northward to New England. Therefore, the
WPC has issued a Slight Risk of excessive rainfall over parts of the
northern Mid-Atlantic Coast northward to New England through Tuesday
morning. The associated heavy rain will create mainly localized areas of
flash flooding, with urban areas, roads, and small streams the most
vulnerable.

In addition, the storm will produce showers and thunderstorms over the
northern Mid-Atlantic Coast/southern New England Coast. The threat of
heavy rain ends on Tuesday as the system moves farther into Canada.

Moreover, in the wake of the deep storm, upper-level energy over the Great
Lakes/Ohio Valley moves eastward to the Northeast Coast by Tuesday
evening. The energy and cold air will aid in creating lake-effect snow
downwind of the Great Lakes and upslope snow over parts of the
Northern/Central Appalachians on Monday into Wednesday. On Monday, the
heaviest snow will be over parts of the Central Appalachians and southeast
from Lake Michigan in Michigan and Indiana. Additionally, another area of
the heaviest snow will be along the central and eastern shore of Lake Erie
in Ohio and New York State. The Lake-effect snow will be much lighter on
Tuesday and end over the Upper Great Lakes.

Meanwhile, a front moving onshore over the West Coast on Monday will
produce rain over most of the Pacific Northwest on Monday into Tuesday
evening and California on Monday into Wednesday morning. The system will
also produce locally heavy snow over the highest elevations of the Sierra
Nevada Mountains and lighter snow over the highest elevations of the
Cascades and parts of Idaho and Nevada.


Ziegenfelder


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php