**This post is dedicated to all former and active soldiers and veterans across the Armed Forces.**
I was taking a look at the long range this morning, and decided it was time to do a post on what my thoughts for the middle and end of November are. However, as I was sifting through the data I wanted to include in this post, I came upon the realization that this data indicated a threat for a potentially major winter storm around the Thanksgiving timeframe. Let's jump right in. We'll start off with the long range thoughts, and then go into the major winter storm threat. At this time, the winter storm discussion remains preliminary. Nothing is set in stone for this potential, and the reason I include 'major' in the possibility is due to certain composites I have at my disposal that indicate this could be a big winter storm. Again, it's nowhere near certain. But let's begin.
Composites of November MJO phases 1 and 2 reveal that the West, Plains and Midwest experience cooler temperatures in Phase 1, with a very wet pattern for the Midwest, Gulf Coast and Ohio Valley in that same phase. The East Coast ends up warm and dry for Phase 1, but the opposite is true for Phase 2. The Plains experience warm weather and dry conditions in Phase 2, while the East is bathed in cooler weather. Per the latest teleconnection guidance and MJO forecasts, I would expect a cool Central and East US for the days leading up to Thanksgiving, with the wet pattern possibly persisting across the Central and portions of the East US. Because model guidance has the MJO so weak in the long range, I'm hesitant to say it will have a big impact on the weather pattern for the end of November, but I am confident in saying that it will have at least a slight impact.
Based on all of the teleconnections and indexes presented to me, it looks as if the weather pattern will undergo some change in the next week or two, as a new, more winter-like pattern takes hold near Thanksgiving. This will set the stage for what could be a major winter storm in the US, and that's what we will discuss next.
So what's all of this talk about a Thanksgiving winter storm? It's only November 11- how can I know this is actually a possibility? Well, we know that this is at least a possibility due to the weather experienced in the Bering Sea recently, and the weather East Asia will experience soon.
Joe Renken, weather in the Bering Sea correlates to weather here in the US approximately 2.5 to 3 weeks after the Bering Sea weather anomaly occurs. This storm system in the Bering Sea happened on November 8th, and extrapolating that out 2.5 to 3 weeks ( 17-21 days) leads us to a potential storm system impacting the US around November 25 to 29. Considering November 28th is Thanksgiving, there does appear to be at least decent potential for a winter storm around the Turkey Day timeframe. But this is only scratching the surface of this storm's potential, and for that reason, we'll continue on with the investigation into this potential winter storm.
So, we have tentatively established that there will be a Thanksgiving winter storm. Where would this storm go? Well, we can get a decent idea from not only the aforementioned teleconnection discussion, but also from a set of composites I outlined for the Midwest and Northeast for major storm systems.
Let's outline what we are expecting in terms of teleconnections for the time around Thanksgiving- more specifically, the November 24-29 period for when this storm could occur. The Arctic Oscillation is expected to be neutral or negative for this timeframe, meaning there may be cold air available for a winter storm and not just a regular storm system. The North Atlantic Oscillation should be in neutral or negative territory, which tells us the energy from this storm should be kept south in the Plains, following the probably-positive (or neutral) PNA, which ought to encourage this storm system to head into the Plains, Midwest or Ohio Valley. The EPO will most likely be negative, and this helps out the cold air idea that the negative Arctic Oscillation should try to establish for this storm system. So now that we've established that there should be a neutral/negative AO, a neutral/negative NAO, a neutral/positive PNA, and a negative EPO, let's take a look at some composites I made up for the Midwest for major winter storm systems and their relationships to teleconnections.
Legend on left shows number of storms.
I do have snowstorm composites for the Northeast as well, but the teleconnection composites aren't nearly as definitive on which phase is more favorable as the Midwest composite is. What I did draw from the MJO Northeast winter storm composite, however, is that the latter MJO phases (Phases 7-2) are most favorable for Northeast winter storms. The negative NAO and favorable MJO composite would seem to lend a hand to the Northeast in terms of this winter storm potential, although right now, I personally see the Midwest, Plains and Ohio Valley at risk for this system. But as is with these long range projections, it's not set in stone.
|WARNING: This graphic is unlikely to verify as is shown. I am showing it because the GFS may have caught on to this idea for one run, but I am NOT endorsing it in any way, other than just to point it out.|