As we begin to progress through this week, our 60s are long gone from here. 40s and 50s will return as our highs across the area, but that's not the point I'm making here in terms of our winter. The bigger story is what could be occurring as we head into mid-January (and I warned folks earlier about how the warm January forecasts are truly in danger). Now try to bear with me on what I have come across while taking a look at some of the data regarding our Northern Hemisphere pattern. I can't promise that I explained it all perfectly but I did the best I could to interpret my findings so keep that in mind.
NOTE: This is what I gathered from the previous runs of some of the modeling (mainly Euro), so the new runs DO NOT apply to this...
Alright. Going back to late December when our Christmas Storm was forming out west, our pattern featured the Greenland Block sitting up north with our East Pacific trough in place and an upper level low sitting off the East Coast. Meanwhile, a piece of energy entering southwestern California (developing system) was ready to make its way across the Southern U.S. Now we all know that eventually, that system ended up bringing us our snow from late Christmas Eve and early Christmas Day thanks to our two streams phasing at just the right time to help amplify that storm. As that lifted out on the 26th, the pattern shifted to where troughing was now taking place along the West Coast, ridging through West-Central U.S. and into Western Canada, and then troughing over the Eastern U.S. Are you with me so far (at least I hope so haha)?
Moving along to yesterday (per 0z Euro data), the pattern shifts to where ridging takes place in Alaska with a trough diving through Central U.S. From there, I begin to notice something about our Greenland Blocking that caught my interest greatly, and that was the sign of it beginning to strengthen...powerfully. From hours 72-120, that block becomes much greater than it was. The polar vortex has no choice but to head southward after our block moves westward and soon ends up being displaced to where the Great Lakes are get hammered by this nasty intrusion of cold air. Around this time, a disturbance that showed up on the 72hr. ends up as a potential coastal storm for the upcoming weekend (more likely for the northeastern states), but those details are still being worked out. The block at this point has become even more powerful (and that word is starting to sound like an understatement at this point).
Now as for the 0z Euro Ensembles, the energy is a bit more powerful in this case. On Jan. 6, our southern feature at 1007mb is off the NC coast from Cape Hatteras that has swung through the SE. At this point, if anything did happen with it, we would see a bit of snow out this but nothing to get excited about. Also to our north, an upper air feature settles in place over the Great Lakes associated with the PV. That eventually combines with that southern feature and ends up becoming a major storm system for the NE with that arctic air beginning to intrude over the NE and MA.
Heading toward hr. 168 on the Euro (Jan. 9th), the PV gets displaced WAY south by a few hundred miles or so. The reason for that is because the model now shows that block as a VERY MASSIVE (from NE Canada all the way to Yukon)! With that vortex being this far south, any southern system just gets suppressed quite a bit. That low is pushed into southern MS and AL and by Day 10, it ends up trying to traverse along the East Coast but is still SE of Hatteras. When it leaves, that arctic air grasps the SE and we are looking at a nasty outbreak forming. Speaking of this setup, the CMC at Day 7 (hr. 174) wants to change this and cause an over-running pattern instead, which would have the moisture flow from TX toward the Carolinas and VA while the arctic air is pressing southward. Granted this isn't a major system being depicted here, but I figured I mention it for the sake of it.
Now as for GFS, I'm not too concerned about what it showed mainly because of what it has done with our PV. The model takes this and places the vortex in the NE around Boston! I wholeheartedly doubt this will verify due to it handling the feature way too far south. In this case, our shortwave would get utterly destroyed by this and you have absolutely nothing to work with. Interesting to note, this would bring some -15 850s to parts of the Eastern U.S. which is very brutal for some folks.
At 500mb on the 12z Euro during hr. 216, it models the PV back in the Dakotas thanks to it having the Gulf low present with blocking going from Eastern Canada to the Northern slopes of Alaska. Euro ensembles has a disturbance taking shape in the Plains with a jet stream flow from Japan all the way across the southeastern states with that Alaskan Ridge still there. This tells me that a stormy pattern is coming up later on, which makes things interesting down the road. Euro at Day 10 at hr. 240 has the vortex sitting over Pittsburgh of all places with this dip taking place across the Central U.S. That dip represents something known as the Siberian Express. With the ridge along the West Coast and the block settling over Eastern Canada, that arctic air gets spilled southward and toward the Eastern U.S. Consequently, this causes VERY COLD air to take over most of the U.S., even down across parts of the Deep South such as the Panhandle of Texas or Arkansas!! Back across our region per 12z OP, there are -14 to -16 850s over most of NC with -20 850s in the Apps! Unbelievable of how powerful this arctic air is. Then finally on the 12z Euro Ens., they show those very cold anomalies pushing eastward into the Eastern U.S.
Having all that said, we could be easily averaging this month as below average if that arctic intrusion comes to play. Course, this will limit our precipitation chances but we'll see. This was just something I wanted to summarize from last night's runs but didn't get a chance to type this due to my illness throughout yesterday (had a massive headache and an upset stomach). Speaking of precipitation, while this weekend's not looking impressive, next weekend seems quite promising and could be a significant hit if this pattern adjusts for such, but I'll explain that later. For now, take care everyone.
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