*If you just want a plain, non-technical forecast; skip to the part that says "non-technical" forecast.
Over the past few days, the model consensus for the track of this potentially significant storm has trended well east. So far east in fact, that the area would have no problem seeing an all-snow event. And several models do suggest the potential for a period of significant snowfall across the area (mainly east of Interstate 69. The heaviest snowfall will remain in Northwest Ohio and southeast).
But don't get excited yet. Several models have actually trended so far east that the area gets little more than a few snow showers, and lake effect after the storm. Some of the global models depict a storm moving from the Southeast and transfering to the East Coast instead of a low that travels into Kentucky, and then transfers to the East Coast (which would bring us decently heavy snowfall accumulations).
Many meteorologists (especially meteorologists from the East) would probably disagree with me on this next point, but I would like to put it on the table for now. One of the main reasons why the consensus track has trended east is because of the current trough of low pressure that is currently located along the East Coast. The trough will push northeast, and become trapped by a developing ridge over the Atlantic (NAO transitioning to its neutral or positive phase around Christmas). At the same time, instead of breaking down the block over Northeast Canada it shifts it west, into the Hudson Bay and regions farther west. Eventually, depending on how neutral or positive the NAO goes, will determine how strong of a rex block will develop. Current trends would indicate that because the PNA is still neutral to negative, that it should go at least to near neutral in coming days. I believe that the Euro is doing a better job (again, most would disagree with me) with handling a weaker rex block (actually, its not really a true rex block. A true rex block is an open wave pattern. In this case, the lows on either side of the block over Canada are closed, making it more similar to an omega block.) over Maritime Canada and the North Atlantic. This would tell me (as well as past analogues) that models will eventually shift back farther west. Not only this, but I believe that some of the models are over doing the strength of the initial clipper for Christmas Eve and Christmas Day. This would affect the eventual path of the storm as well. And because I believe that there will be a weaker rex block, the shortwave will travel slightly farther north than what models are indicating. While this would eventually help "strengthen" the rex block, it wouldn't do so as much as indicated by computer models.
While I do not disagree with a primary low that transfers to the East Coast, I believe that recent model trends reflect "pseudo-reality". What I mean by this is that I believe the models are too weak, and too far east with the primary surface low. In situations such as this, the surface low will likely track through Kentucky, and southern Ohio, which would bring the area a good 6-12 inches of snow (mainly south of Route 6). BUT, it will primarily depend on how quickly the secondary low develops. Sometimes, models depict this happening too early, and some too slowly. Time will tell what will happen. At the current time, I would think it is possible that secondary development occurs faster, but it will depend on the strength of the shortwave over Texas, and how quickly energy can consolidate. Since the ECMWF generally has a better grip on these types of things, I can say that having one primary shortwave is definitely more probable then having a weaker initial wave, with several smaller ones as well.
Here's my storm track map:
This map is based upon the latest forecasts, and factoring in other "causations" as well. If the east trend continues today, I will shift the snow region farther eastward, but this is my best guess at this time. Most of the region will be in the dark blue, and depending on the track of the system, could bring us some decent snowfall amounts. I would expect a good 1-8 inches of snow in the dark blue (one on the edge, 8 closer to the pink). In the pink, I'm expecting a good 9-15 inches, with some areas getting 15-18 inches (isolated).
Over the past few days, the model consensus for the track of this potentially significant storm has trended well east. So far east in fact, that the area would have no problem seeing an all-snow event. And several models do suggest the potential for a period of significant snowfall across the area (mainly east of Interstate 69. The heaviest snowfall will remain in Northwest Ohio and southeast).
But don't get excited yet. Several models have actually trended so far east that the area gets little more than a few snow showers, and lake effect after the storm. Some of the global models depict a storm moving from the Southeast and transfering to the East Coast instead of a low that travels into Kentucky, and then transfers to the East Coast (which would bring us decently heavy snowfall accumulations).
 |
| Depiction of the large trough in the East which will eventually redevelop the "block". |
Many meteorologists (especially meteorologists from the East) would probably disagree with me on this next point, but I would like to put it on the table for now. One of the main reasons why the consensus track has trended east is because of the current trough of low pressure that is currently located along the East Coast. The trough will push northeast, and become trapped by a developing ridge over the Atlantic (NAO transitioning to its neutral or positive phase around Christmas). At the same time, instead of breaking down the block over Northeast Canada it shifts it west, into the Hudson Bay and regions farther west. Eventually, depending on how neutral or positive the NAO goes, will determine how strong of a rex block will develop. Current trends would indicate that because the PNA is still neutral to negative, that it should go at least to near neutral in coming days. I believe that the Euro is doing a better job (again, most would disagree with me) with handling a weaker rex block (actually, its not really a true rex block. A true rex block is an open wave pattern. In this case, the lows on either side of the block over Canada are closed, making it more similar to an omega block.) over Maritime Canada and the North Atlantic. This would tell me (as well as past analogues) that models will eventually shift back farther west. Not only this, but I believe that some of the models are over doing the strength of the initial clipper for Christmas Eve and Christmas Day. This would affect the eventual path of the storm as well. And because I believe that there will be a weaker rex block, the shortwave will travel slightly farther north than what models are indicating. While this would eventually help "strengthen" the rex block, it wouldn't do so as much as indicated by computer models.
 |
| 00z ECMWF's forecast of the blocking pattern over Canada. |
While I do not disagree with a primary low that transfers to the East Coast, I believe that recent model trends reflect "pseudo-reality". What I mean by this is that I believe the models are too weak, and too far east with the primary surface low. In situations such as this, the surface low will likely track through Kentucky, and southern Ohio, which would bring the area a good 6-12 inches of snow (mainly south of Route 6). BUT, it will primarily depend on how quickly the secondary low develops. Sometimes, models depict this happening too early, and some too slowly. Time will tell what will happen. At the current time, I would think it is possible that secondary development occurs faster, but it will depend on the strength of the shortwave over Texas, and how quickly energy can consolidate. Since the ECMWF generally has a better grip on these types of things, I can say that having one primary shortwave is definitely more probable then having a weaker initial wave, with several smaller ones as well.
Here's my storm track map:
 |
| Preliminary storm map. |
This map is based upon the latest forecasts, and factoring in other "causations" as well. If the east trend continues today, I will shift the snow region farther eastward, but this is my best guess at this time. Most of the region will be in the dark blue, and depending on the track of the system, could bring us some decent snowfall amounts. I would expect a good 1-8 inches of snow in the dark blue (one on the edge, 8 closer to the pink). In the pink, I'm expecting a good 9-15 inches, with some areas getting 15-18 inches (isolated).
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