1) There will be a significant snowstorm somewhere in the East next week
2) It appears to be a potentially major (12"+) storm - - but we are not certain where exactly this happens
I'm confident in those two things. Now let's talk about what this could potentially be for WHERE it hits. I do believe this has potential to be a historic crippling snow for somewhere in the Mid Atlantic - - let's talk about that.
1) Confident that somewhere will see 12-24" of Heavy Wet snow over a fairly large area. Impossible to tell exactly where. But Power outages - significant tree damage appears likely in some place.
2) Heavy snowfall rates - 1-2" an hour... picture January 17th of this past year on a much large scale. For Carroll County this was a bad storm - 12" of heavy wet snow. It appears that this magnitude of a storm could happen on a much larger scale. If you recall Interstate 77 was shutdown in Bland County and was all but shut down from Fancy Gap to Wytheville. Appears that this type of standstill will happen SOMEWHERE - - on a larger scale with this storm.
To summarize, I am confident in a Major Storm - - Crippling - - Historic - - for somewhere in the East. Exact locations to be pinned down.
NOW let's talk about the setup and some things that can possibly clue us in.
The storm setup is one that for snow at this latitude in the Mid Atlantic is pretty atypical. As you all know, we are in a rather cold pattern, with a trough in place over the Eastern United States. Early next week, a strong piece of upper level energy, just now entering the Pacific NW, will track across the Northern Plains. What is key here is 2 things .. 1) This is not of Arctic Origin - - Pacific, meaning it is likely a stronger piece of energy. 2) It is a strong piece of Upper Level Energy - - which I'll expand upon later. Long story short, it is not your typical "clipper" type of dry energy coming out of the NW. AT the same time, a small surface low will form in the South Central Tennessee Valley and ride up west of the Appalachians. As you know, typically this is NOT a good track for snow in our area. In fact, we will probably see some rain on Tuesday as a warm front with the initial surface low passes somewhat southwest of our area. However, what is KEY here, is the Upper Level Energy diving through the Plains. This is a STRONG piece of energy and will dive south as the jet stream has a trough over area. What essentially going to happen is, this ULL, the stronger piece of energy will become the stronger piece of energy. It will become Vertically stacked, and essentially blow into a major low pressure system wherever this happens. The term we use for this is "digging". How far South does the ULL, or that energy over the Northern Plains "dig".
|here you can see the "track" of the ULl crossing NC. This would be a brilliant track for snow from I40 North|
There are some signals that show us this will happen at a latitude that is rather unusual for this time of year. The big one here is this area of high pressure over Eastern Canada - - otherwise known as Blocking. For days I have said that I don't think this will setup and HOLD. It appears that it won't hold. It will shift and breakdown after next week. However, it does appear more and more like it will hold in place enough to shove this ULL south of the Ohio River. That is critical because typically, it doesn't happen that way. A typical track is somewhere north of the Mason Dixon Line, but again, the blocking appears to be strong enough to force this ULL south of the Mason Dixon Line. This tells me that this low will explode likely somewhere over the Carolina's or Southern Virginia.
|This is an image of the Block over Eastern Canada. You can see a MASSIVE area of High Pressure preventing the storm from cutting essentially North of Virginia.|
|Today's EURO run at the 500MB level.. here we can see thw track of the ULL - - good for snow over Virginia. You can se the ULL begin to go negative in this frame.|
|Here is the GFS, a bit courser of a model, but very good agreement between the two.|
However, we haven't seen too much consistency in this throughout the past few days. Yesterday most models kept this north of here, tracking it across VA and off the Delmarva Coast. This would shift the snow to the North. Some of the models dug the energy all the way into Georgia and off the South Carolina Coast - - missing Virginia to the SOUTH. So again here, there hasn't been a consistency over the past few days within the operational models.
|If the ULL tracks between these two red lines Virginia Would get crushed. Every Model shows a track between these two lines.|
|For fun and games, here is the EURO snow map for today. Has 8-16" from VA/NC border north and a bullseye of 1-2' over the Shenandoah. NOT a forecast, just a model output.|
Some closing thoughts. The NC/VA border counties appear IMO to be too far South to be in the bulls-eye at this point in time. Yes with this track it appears we will see some very good snows. But it appears the heaviest snow could setup north of us over the Shenandoah Valley.
YES NOVA- - This storm looks to be very large - - so I think you get in on it too.
North Carolina is the big question mark - - particularly south of I-40 or US 421. Need it to dig a bit further South. Do think far Northern NC is very much in the game though.
I won't put out a snow map yet. Remember, we want a track along or SOUTH of Interstate 40. A track further North of this is still possible. I will post an update tomorrow and again Monday as the storm draws closer. We are within almost 3 days of the storm now so we are entering a window of Higher confidence. The specifics aren't important now - - just know that the Mid Atlantic will likely bit very hard in some portion by Thursday Morning.