A very rainy day with cool temperatures and breezy conditions will turn into a snowy evening for some as temperatures turn colder. Keep in mind that it will take a while before a changeover from rain to snow occurs. We maintain that Upstate towns will see all rain until a short window of time this evening when snow will fall across many Upstate towns. Western NC will transition from rain to snow late this afternoon and stay in heavy snow for a longer period of time.
Since there will be a two to three-hour window for the snow to fall in the Upstate, accumulations of a dusting to 3" will be possible. In other SC areas, there will be less of a window for snow to fall and briefs bursts of inconsistent snow OR no snow at all will lead to no accumulations.
River Flood Warning: This is in effect for Transylvani and Henderson counties until 11:00pm Saturday. This is due to river rising which will continue even after the rain has stopped tonight. Watch out for flooding on roads and there could be road-washouts in these areas.
Flood Watch: An additional 1-3" of rain is anticipated today across our area. A Flood watch has been issued for Western NC as well as most of the Upstate north of the following counties: Greenwood, Abbeville and portions of NE Georgia. Watch out for flooding on roads and river rises in these areas as well .
Snow - Timing: After it rains most of the day across our area, (1) snow will begin first in Western NC between the hours of 3pm and 6pm where the Winter Storm Warning is posted. There will be a window of four-seven or so hours for heavy snow to accumulate.
(2) In the northern Upstate: specifically northern Greenville, northern Pickens, northern Spartanburg, Cherokee and northern Pickens county (areas within the Winter Weather Advisory), I expect the snow will start by late afternoon or early evening from 4pm to 7pm or so and there will be a window of three or more hours for heavy snow to accumulate.
(3) For NE Georgia as well as all other Upstate areas, the rain will last longer as it will take more time for the cold pocket of air in the mid-levels underneath this upper-level system to move over our heads. Rain will transition to snow between the hours of 5pm and 9pm. Some towns not be located directly underneath heavy precipitation or cold-core leaving those areas with all rain.
Accumulations: Western NC valley towns will pick up between 2 and 5" of snow while higher terrain will be in line for very heavy accumulations of 6-12" (with the highest in spotty areas likely near Cataloochee and the Balsam Mountains). Travel concerns will be widespread in the Mountains and some power outages may occur due to the heavy snow.
A new Winter Weather Advisory area has been posted for ALL of Greenville, Anderson, Spartanburg, Oconee and Pickens counties. Dusting to 1" and as high as 2-3" are possible in spotty areas, yet some areas will see more rain where heavy precipitation bands do not set up and are unable to pull down the mid-level cold air.
Portions of the northern-most Upstate under a Winter Weather Advisory are expected to see tough road conditions develop this evening and tonight as 2-5" is likely (depending on elevation). These are areas like northern Oconee, Sunset, Pumpkintown, Table Rock, Ceasars Head, close to Slater-Marietta as well as Hogback Mtn., Landrum, Inman, Gaffney and Blacksburg.
**Again, spotty accumulations of a dusting-3" or so are very possible around Anderson, Greenville, Spartanburg, Union and Pickens. In fact, Spartanburg, Cherokee and portions of Union Co. have a chance at closer to 2-3". This will be solely dependent upon where heavy bands of precip changing to snow will occur and remain as pivoting, nearly-stationary snow bands this evening. This is a challenging forecast as to where the heavy snow will set up here in SC due to small-scale processes (at the mesoscale level) which are tough to pinpoint at this time.
We'll have more this afternoon and tonight as Kendra will provide updates.
Sunny Tomorrow: If you are tired of the cloudy, cold scenario, you'll be pleased with tomorrow's conditions as sunshine returns with cool conditions sticking around. Snow in Western NC will melt slowly while any Upstate snow left over will melt very quickly tomorrow mid-morning to lunch as the sun comes out.