HEAVY THUNDERSNOW POSSIBLE IN NC/SC..NWS GREENVILLE/SPTG

[hurricanedude]

A low pressure system at the surface will move southeast from the Ohio River valley tonight... and reach the western Carolinas and northeast Georgia Tuesday. The low is expected to move southeast through the Savannah River valley during the day. An associated upper level low pressure area... is expected to move across western North Carolina at about the same time.

Snow is expected to fall in the mountains Tuesday morning and persist through much of the day. A Winter Storm Warning has been issued for most of the Tennessee border counties in North Carolina for heavy snowfall... while the remainder of the North Carolina mountains are expected to receive light accumulations of 1 to 3 inches.

Snow... mixed with rain... is expected along and north of Interstate 40 from the eastern slopes of the mountains... to the northwest Piedmont. In those areas... accumulations could reach an inch or so... with higher accumulations near the mountains.

Rain will become mixed with snow... or change to snow in some areas... from northeast Georgia... across upstate South Carolina... to the southern foothills and southern Piedmont in North Carolina. Accumulations are expected to be an inch or less around Charlotte... to just trace or light accumulations from Gaffney southwest to Hartwell Georgia. The South Carolina and Georgia mountains could have an inch or so. Areas from Elberton to Greenwood may have some snow mixed with rain.

There are a couple of factors which make snowfall accumulation forecasts quite difficult in this case. First... warm ground temperatures may prevent significant accumulations... especially early in the snowfall. Even through the event... accumulations on road surfaces may not be significant... especially some distance from the mountains.

Second... there is the potential for heavy showers and even some thunderstorms to occur during mid day and into the afternoon. Heavy showers or storms can yield very high snowfall rates which can cause rapid accumulations to occur. The heavy wet snowfall could add up to several inches quickly in localized bands... especially on grassy surfaces.

Listen for later information on the developing winter weather situation.

[JCT777]

The central/western Carolinas have been the sweet spot for snow during the past 3 to 4 weeks.

[Stormsfury]

The GFS has definitely trended wetter with this system ... but what concerns me ... for South Carolina is how much of this is PRE-FRONTAL and quite possibly a small line of thunderstorms ... although I believe snow will mix in with rain in just about all of South Carolina, some locations in North Carolina and even the northern portions of South Carolina have good chances of accumulating snow, and some of it could be quite heavy ...

Remember, 1000-850mb thicknesses are somewhat marginal, (1000-500mb thickness are more than enough to support decent snow growth), however, stronger sun angle, and what's interesting are just how dry the air is currently. Moisture recovery is expected with this with some WAA ahead of the diving s/w ... the funny thing is with such a dynamic system that the stronger sun angle may contribute to a little stronger instability, and in turn counterbalance the SFC temperatures in help drawing very cold air aloft, especially where sufficient convection development occurs ...

The setup is clearly there for some locations to get thunder with such a dynamic system, and SPC actually has a generalized outlook for tomorrow's system ... with the potential for isolated wind/hail damage. Steep lapse rates in the order of 7ºC/KM with a strong mid and upper level jet on the southern side of the digging trough... this could easily be a situation where one location gets heavy snow, and 3 miles away, it's 3º warmer and just rain (or rain/snow mix) ...

[JQ Public]

we may even get an inch...gluck guys!