Everything is still lining up for our area to get in on some rain Monday (Christmas Eve) and than again on Tuesday (Christmas Day). Strong to severe storms will be possible, especially south of Interstate-85. The rain will move out by Wednesday morning. By late Wednesday, as the strong low pressure system track northeast of us, the Western NC Mountains will turn windy and much colder as a transition to snow takes place in the high elevations.
As our pattern has shifted to rainy/wet with more subtropical energy infused into it, this Christmas system will be one in a number of systems responsible for flipping the pattern to cold around the 29th or 30th through the first few days of January. Importantly, there are signs that this could be an extended cold snap for us lasting for more than three to four days into the new year. As this happens, moisture availability for SC/NC is uncertain, but it is interesting to note that the subtropical jet stream stays active.
Tonight's run of the 0z European forecast model showed a Canadian system diving into the base a subtropical system and phasing with it over the Midwest around the 28th. All the while, a key piece missing much of last winter and this past fall (a ridge of high pressure present out west) pokes up into British Columbia later on in the run and this taps into Alaskan cold sending it southeast. All of these factors considered, it sure looks like a colder start to 2013. If nothing else, there is a high chance that January 2013 starts off much colder than the insect-infested start of January 2012 in the SE.
Still, no telling just yet if any moisture will cruise into the mix by early January. Sometimes the cold can be too strong and lead to a bone-dry chill with a storm track that is far too suppressed to our south. That scenario isn't likely, but is possible.
Lastly, I sincerely hope everyone has a relaxing and enjoyable Christmas.
I'll be here to update you through Wednesday as Kendra and Alex are enjoying some well-deserved time off.