The pattern is changing and we are going into a much stormier pattern starting this upcoming weekend. If you are a snow lover you might need to wait a while longer for a “real” threat of wintry weather. As is often the case with the 1st storm in a pattern change you just don’t have the cold air for snow. In the Carolinas you’d like to see the cold air establish itself first then get a storm if you are a snow lover. This weekends storm is just lacking serious cold air to work with. It doesn’t mean we can’t see some wintry mix especially in the mountains or even north of I-40 though.
Model Run Down:
Right now, all the models are pointing to a cold rain east of the mountains. There is some hint of weak cold air damming up against the mountains Saturday which could lead to some minor icing along the Blue Ridge. The upgraded GFS shows a very cold rain with a wintry mix along the mountains. Likely some freezing rain but even snow at higher elevations.
The temperatures just look way too warm for snow as a warm nose of air, at 850mb will keep this mainly a cold rain or light wintry mix where the cold dry air holds up against the mountains. The precipitation types or P-Types show a rain and ice mix for the mountains but for some reason the GFS has a band of light snow along and north of I-40. This appears to be an error as the temperature profiles don’t support this and likely this is just an error in the model.
The ECMWF soundings and thicknesses all show rain or some ice but certainly not snow. People get caught up in these snowfall maps but realize that the ECMWF model takes all winter precipitation where there is a 32° 850mb or surface temperature and converts it all to snow at a 10:1 ratio. So be cautious when looking at these snowfall maps make sure to cross check the thicknesses and temperatures profiles.
The ECMWF shows a much stronger storm with much more moisture but notice the 540 line is nowhere in the area. This is the blue line where the rain snow’line typically is. The Candian model also supports an all rain event east of the mountains with a wintry mix in the mountains.
Conclusion and thoughts:
This weekend is the 1st storm in what will be an active storm track through the end of the year. Snow lovers this isn’t your storm yet! This is the one that lays the groundwork for the next few. I see this as a cold rain east of the mountains with a light icing event for the mountains and adjacent foothills. It’s still 6 days out, but there is enough agreement in the guidance and pattern to think we see mainly rain east of the mountains with a wintry mix in the mountians. The only real question is the strength of the storm and track. So stay tuned as this winter pattern starts to build in this weekend.