A few changes are worth noting for the post-Christmas storm now.
It appears my original track was correct; tracking from western Tennessee into Eastern Kentucky. The SREF mean, the 12z and 18z NAM, and the GFS all reflect this. The Euro still seems to be a bit further south and east, but that appears to be due to the aggressive development of the secondary low near the coast on the model. At this point, even though models did trend slightly today (I wouldn't really call it a trend given that we've only seen one legitimate model run from each of the main models; More than likely, I wouldn't doubt a shift west tonight as a weak shortwave exits off the Northeast coast by tomorrow morning, causing height rises behind it), I think the storm's track is pretty set in stone, with a few wobbles here in there. A shift west and north in the storm would allow for the area to experience heavier snowfall rates with the possibility of sleet mixing in as far north as Lima (a 25-50 mile shift northwest that is). If it stays the same, I'll get to that in a moment with my latest map. If it trends east, expect lower snowfall totals, but higher potential for fluffier, accumulating snowfall. The fluffier snowflakes will accumulate in a shorter period of time, but since snowfall rates would be lighter, then I wouldn't expect more than 2-5 inches if the storm shifted east. At this time though, I don't think its very wise to trust the global models as they are heading into a very bad timeframe. They aren't very accurate with handling the 24-48 hour forecast periods, which is the timeframe which the storm is in now. And because the mesoscale guidance is still about 50-100 miles northwest of the main global guidance, I think its safe to call that the GFS/ECMWF/GGEM will all shift at least slightly northwest in the days before the storm.
A few other aspects worth noting is that even though Northwest Ohio and Northeast Indiana receive a significant snowstorm, the Interior Northeast will also see one. In fact, snowfall totals as high as 18 inches are expected over a large portion of New York State and Pennsylvania. If it weren't for the secondary low, these snowfall totals would not be nearly as high for the Northeast.
Now.. Here's my latest map! Explanations and details come below the map:
Now comes the full explanation.
Models continue to bring a strong Gulf low from far eastern Texas northeastward into Eastern Kentucky. This type of a track is called an Inside Runner, and is generally the most favorable for snowfall in the Upper Ohio Valley and Lower Great Lakes (where we are). It is a prime track because it draws in copious amounts of moisture from the Gulf of Mexico, has excellent access to cold air from the north, and it tracks south of the area, bringing the heaviest snowfall to us or just south of the area. This looks to happen with this storm as well. While the NWS has generally stayed conservative (4-7 inches east of I-69, which is still fairly decent for the area, most models are forecasting heavier snowfall amounts. So far, the GFS and ECMWF are both advertising the lowest snowfall amounts of 4-7 inches, in agreement with the NWS. The NAM is showing 8-10 inches, the Hi-resolution NAM is showing 8-10 inches, and the SREF is similar. So it appears that snowfall from U.S. 24 and south will be in the range of 8-11 inches or so, with lower amounts of 5-7 inches north of that. This is all dependent on the track of the low, which could shift in the next few model runs or so.
There will be several ingredients that need to be closely monitored over the next day or so to properly determine snowfall totals and placement. One of them is frontogenesis. Frontogenesis occurs when a temperature gradient becomes "tighter" or the temperature change across a given distance increases with time. Frontogenesis will initiate small mesoscale bands of heavy snowfall which will aid in snowfall amounts. These bands will not be detected easily until Wednesday morning. Another factor is synoptic scale forcing, such as q-vector convergence and mesoscale uplift from the right entrance region of a jet streak over Canada. This will also aid in the development of slantwise convection which will also be driven by frontogenetical bands by mid-afternoon Wednesday. Eventually, this will weaken, and that is also why areas north of Route 6 won't see as heavy of snow totals. Eventually, I believe that snow will become lighter by about 8 p.m. Wednesday, and tapering off by midnight.
In the case of the heavy snow banding, these bands will most likely set up from Fort Wayne to Toledo, but that is just my best guess at this time. It is too difficult to determine right now where these bands of heavier snowfall will set up, and therefore, I won't know until early Wednesday morning at the onset of precipitation. Visit my Facebook Page for further details with regards to the evolution of this potentially significant snow storm.
Here's a visual map of the snowfall totals that the High-resolution NAM is "printing" out. It brings most if not all of the area 6+ inches of snow, with higher amounts near Fort Wayne and southeast.
It appears my original track was correct; tracking from western Tennessee into Eastern Kentucky. The SREF mean, the 12z and 18z NAM, and the GFS all reflect this. The Euro still seems to be a bit further south and east, but that appears to be due to the aggressive development of the secondary low near the coast on the model. At this point, even though models did trend slightly today (I wouldn't really call it a trend given that we've only seen one legitimate model run from each of the main models; More than likely, I wouldn't doubt a shift west tonight as a weak shortwave exits off the Northeast coast by tomorrow morning, causing height rises behind it), I think the storm's track is pretty set in stone, with a few wobbles here in there. A shift west and north in the storm would allow for the area to experience heavier snowfall rates with the possibility of sleet mixing in as far north as Lima (a 25-50 mile shift northwest that is). If it stays the same, I'll get to that in a moment with my latest map. If it trends east, expect lower snowfall totals, but higher potential for fluffier, accumulating snowfall. The fluffier snowflakes will accumulate in a shorter period of time, but since snowfall rates would be lighter, then I wouldn't expect more than 2-5 inches if the storm shifted east. At this time though, I don't think its very wise to trust the global models as they are heading into a very bad timeframe. They aren't very accurate with handling the 24-48 hour forecast periods, which is the timeframe which the storm is in now. And because the mesoscale guidance is still about 50-100 miles northwest of the main global guidance, I think its safe to call that the GFS/ECMWF/GGEM will all shift at least slightly northwest in the days before the storm.
A few other aspects worth noting is that even though Northwest Ohio and Northeast Indiana receive a significant snowstorm, the Interior Northeast will also see one. In fact, snowfall totals as high as 18 inches are expected over a large portion of New York State and Pennsylvania. If it weren't for the secondary low, these snowfall totals would not be nearly as high for the Northeast.
Now.. Here's my latest map! Explanations and details come below the map:
Now comes the full explanation.
Models continue to bring a strong Gulf low from far eastern Texas northeastward into Eastern Kentucky. This type of a track is called an Inside Runner, and is generally the most favorable for snowfall in the Upper Ohio Valley and Lower Great Lakes (where we are). It is a prime track because it draws in copious amounts of moisture from the Gulf of Mexico, has excellent access to cold air from the north, and it tracks south of the area, bringing the heaviest snowfall to us or just south of the area. This looks to happen with this storm as well. While the NWS has generally stayed conservative (4-7 inches east of I-69, which is still fairly decent for the area, most models are forecasting heavier snowfall amounts. So far, the GFS and ECMWF are both advertising the lowest snowfall amounts of 4-7 inches, in agreement with the NWS. The NAM is showing 8-10 inches, the Hi-resolution NAM is showing 8-10 inches, and the SREF is similar. So it appears that snowfall from U.S. 24 and south will be in the range of 8-11 inches or so, with lower amounts of 5-7 inches north of that. This is all dependent on the track of the low, which could shift in the next few model runs or so.
There will be several ingredients that need to be closely monitored over the next day or so to properly determine snowfall totals and placement. One of them is frontogenesis. Frontogenesis occurs when a temperature gradient becomes "tighter" or the temperature change across a given distance increases with time. Frontogenesis will initiate small mesoscale bands of heavy snowfall which will aid in snowfall amounts. These bands will not be detected easily until Wednesday morning. Another factor is synoptic scale forcing, such as q-vector convergence and mesoscale uplift from the right entrance region of a jet streak over Canada. This will also aid in the development of slantwise convection which will also be driven by frontogenetical bands by mid-afternoon Wednesday. Eventually, this will weaken, and that is also why areas north of Route 6 won't see as heavy of snow totals. Eventually, I believe that snow will become lighter by about 8 p.m. Wednesday, and tapering off by midnight.
In the case of the heavy snow banding, these bands will most likely set up from Fort Wayne to Toledo, but that is just my best guess at this time. It is too difficult to determine right now where these bands of heavier snowfall will set up, and therefore, I won't know until early Wednesday morning at the onset of precipitation. Visit my Facebook Page for further details with regards to the evolution of this potentially significant snow storm.
Here's a visual map of the snowfall totals that the High-resolution NAM is "printing" out. It brings most if not all of the area 6+ inches of snow, with higher amounts near Fort Wayne and southeast.
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