It might have been the 5th warmest Autumn on record in Charlotte and really warm for most of the country but that is about to change. Some of the earliest cold air we have seen in years is poised and ready to invade the lower 48 states next week. This cold air has been building in Siberia for most of the Autumn on the other side of the globe. There they had the 4th highest October snowfall on record. That cold air is already spilling across the Arctic into Alaska and western Canada this weekend.
By next week the jetstream will drive it first into the western U.S. From there the cold will build east through the end of next week. The upper-level pattern shows an incredibly low 500 mb anomaly for this time of year. Basically, a very deep/big dip in the jetstream compared to normal. Both the GFS and ECMWF ensemble models show this, so there is lots of agreement among the two major models.
Looking at the temperature departures from average we are talking maybe 15-20° below average in some spots of the Carolinas. This would mean highs only in the 30s and lows in the teens and 20s, even for Charlotte!
What about rain?
The good news is as this pattern changes to cold a series of storms will sweep across the South including late this weekend and early next week. We often see a strong storm as the jet stream buckles like this to a much different pattern. Much needed rain will fall Sunday through Tuesday.
So any wintry precipitation?
This is always the 1st question asked when I see a pattern change like this. The easy answer is, it’s just too hard to tell so far out, but the 1st ingredient is going to be there; THE COLD AIR! It is almost impossible to nail down a snow or ice forecast more than three-five days out let alone 7-14 days. Don’t fall for the model hype they never verify, but the pattern does favor the chance. The best thing to look at in my opinion are the ensembles chances of 1″ of snow. Right now that shows the mountains with the best chance but little east of the mountains right now. For now, this looks cold only we will have to wait and see if we can sync it up with a storm next week. Stay tuned!