USA National Weather Service update 12.6.2023

Excessive rainfall and flooding potential continues across the PacificNorthwest...

Moderate upslope snow forecast across the central and southernAppalachians today...

Well above average and potentially record-breaking warmth forecastacross the central United States over the next few days...

An Atmospheric River is forecast to continue impacting parts of thePacific Northwest today before precipitation weakens and becomes scattered by the end of the week. The highest rainfall amounts over the next few days are expected to occur over western Oregon and northern California, slightly south of where the heaviest rain has occurred over the last day.

Nevertheless, a few inches of rain across coastal regions of Oregon and northwest California could lead into instances of flooding. Flood Watches, Warnings, and Advisories remain in effect. Snow levels are anticipated to drop back to below 4000 feet by Thursday and limit the snowmelt/runoff potential from the higher terrain as the next wave of moderate precipitation enters the region.

Snow showers and light snow potential also exists across the Appalachians, Great Lakes, and Northeast through Thursday as cold air rushes in from the northwest due to a developing low pressure system in the western Atlantic.

The most noteworthy accumulating snow is forecast to occur along the higher terrain of the central and southern Appalachians through tonight. Winter Weather Advisories extend from the mountainous terrain of western North Carolina to the Allegheny Front of West Virginia and western Maryland. Here, 3 to 6 inches of snow is possible.

Elsewhere, the central U.S. can expect well above temperatures and dry conditions through Friday ahead of the next cold front and storm system to enter the Great Plains. Highs into the 60s as far north as South Dakota and 70s into southern Kansas are forecast, which equates to around 20 to 30 degrees above average when compared to early December climatology. The warmest day will be Thursday, where several daily high temperature records could be broken throughout the Great Plains and Upper Midwest. Meanwhile, as the aforementioned cold front swings through the Rockies on Thursday and approaches the Plains on Friday, unsettled weather and gusty winds are set to return. Moderate to locally heavy snow is possible across the mountainous terrain of the Rockies, as well as into the central High

Plains on Friday. Strong westerly and downsloping winds may also prove to be hazardous across the northern and central High Plains for the end of the week.