This won't be a very big update, as I have other things to look at before making any more detailed forecasts, but I do want to get the word out about this winter-storm that will likely affect the region Friday night through Saturday.
First, the main points of what I expect to happen [and then the gritty "details"].
1.) This will not likely be a "blockbuster-event" like the Groundhog Day blizzard of 2011 was. I am not expecting crippling snowfall and impassable roadways or anything like that. However, this storm will be rather significant for the area, causing quite a few travel delays and accidents. The "good" news is that this storm will be hitting on a weekend, and thus will not disrupt schools or cause any major travel disruptions [especially considering that the snow is likely to begin falling AFTER rush-hour on Friday].
2.) Secondly, I am not expecting any other precipitation type besides snow; thermal profiles throughout the event will remain below-freezing, with max. saturation likely residing in the DGZ [Dendritic Growth Zone], or at least in the lower-half. This will allow for efficient ice-crystal development processes, and thus we shouldn't have much trouble with developing snow over the area Friday-night. The only caveat will be the potential for dry-air at the onset, which will lead to evaporational-cooling.
3.) Lastly, it looks as if snow-totals will be in the 4-6 inch range overall; I know many area meteorologists are going conservative right [many are placing accumulation amounts around 2-4" or 2-5"], but I'm going to go right out and say what the model consensus has. And even this on the low-side of much of the guidance today. Models like the ECMWF, the CMC, and NAM all have a good 5-8 inches of snow for the area, unlike the GFS, which gave us about 3-6 inches of snow. However, I'm not willing to bet on such high snow totals yet, due to problems with actual precipitation production and moisture transport. As for timing, expect snow to begin around 9-11 p.m. Friday night, and last through at least the early afternoon hours Saturday; 18+ hours of moderate snowfall will likely contribute to decent snow totals area-wide.
Now for the "gritty" details.
One of my main concerns as of this point is the potential for mesoscale-snow banding, and frontogenetical-enforcement. When I say "frontogenetical-enforcement", I'm mainly referring to the tightening of the horizontal temperature gradient [in other words, the temperature contrast from one place to another increases, leading to upward vertical motion on a slanted-scale].
In regards to mesoscale-banding, this could potentially lead to the enhancement of snowfall amounts. In fact, the latest 18z NAM run is pointing towards the formation of heavy-snow bands across NW Ohio and N. Indiana late Friday night before the main event gets underway; if this occurs, and the lower-levels saturate quickly enough, it is quite possible that we pick up a quick 2-3 inches of snow in a short-period of time. However, considering that the NAM seems to be having problems with the timing of drier pockets of air [and thus, lulls in snowfall during the overnight hours], it may just be a fluke run. I'll have to monitor the 00z NAM [which is coming out currently] for further trends. However, it is likely that we do see some kind of mesoscale-banding with this event, which will mainly enhance snow totals along and southeast of U.S. 24.
Not only this, but strong, jet-streak circulations will likely enhance the development of moderate-heavy snow bands. The 18z NAM also showed that a small, macro-scale jet over C. Indiana will "couple" with a jet-streak over Canada, producing intense upward vertical motion in between [this happens due to the fact that strong upward motion usually occurs in the left-exit region and the right-entrance region of jet-streaks, and when these are interposed on each other, they enhance dynamics greatly]. If this were to occur, we would expect the development of heavier periods of snow during the day Saturday or in the early morning hours. This will be yet another factor in my snowfall forecast.
But for now, I'm sticking with the 3-5"/4-6" forecast, as it appears to be reasonable at this time.
First, the main points of what I expect to happen [and then the gritty "details"].
1.) This will not likely be a "blockbuster-event" like the Groundhog Day blizzard of 2011 was. I am not expecting crippling snowfall and impassable roadways or anything like that. However, this storm will be rather significant for the area, causing quite a few travel delays and accidents. The "good" news is that this storm will be hitting on a weekend, and thus will not disrupt schools or cause any major travel disruptions [especially considering that the snow is likely to begin falling AFTER rush-hour on Friday].
2.) Secondly, I am not expecting any other precipitation type besides snow; thermal profiles throughout the event will remain below-freezing, with max. saturation likely residing in the DGZ [Dendritic Growth Zone], or at least in the lower-half. This will allow for efficient ice-crystal development processes, and thus we shouldn't have much trouble with developing snow over the area Friday-night. The only caveat will be the potential for dry-air at the onset, which will lead to evaporational-cooling.
3.) Lastly, it looks as if snow-totals will be in the 4-6 inch range overall; I know many area meteorologists are going conservative right [many are placing accumulation amounts around 2-4" or 2-5"], but I'm going to go right out and say what the model consensus has. And even this on the low-side of much of the guidance today. Models like the ECMWF, the CMC, and NAM all have a good 5-8 inches of snow for the area, unlike the GFS, which gave us about 3-6 inches of snow. However, I'm not willing to bet on such high snow totals yet, due to problems with actual precipitation production and moisture transport. As for timing, expect snow to begin around 9-11 p.m. Friday night, and last through at least the early afternoon hours Saturday; 18+ hours of moderate snowfall will likely contribute to decent snow totals area-wide.
Now for the "gritty" details.
One of my main concerns as of this point is the potential for mesoscale-snow banding, and frontogenetical-enforcement. When I say "frontogenetical-enforcement", I'm mainly referring to the tightening of the horizontal temperature gradient [in other words, the temperature contrast from one place to another increases, leading to upward vertical motion on a slanted-scale].
In regards to mesoscale-banding, this could potentially lead to the enhancement of snowfall amounts. In fact, the latest 18z NAM run is pointing towards the formation of heavy-snow bands across NW Ohio and N. Indiana late Friday night before the main event gets underway; if this occurs, and the lower-levels saturate quickly enough, it is quite possible that we pick up a quick 2-3 inches of snow in a short-period of time. However, considering that the NAM seems to be having problems with the timing of drier pockets of air [and thus, lulls in snowfall during the overnight hours], it may just be a fluke run. I'll have to monitor the 00z NAM [which is coming out currently] for further trends. However, it is likely that we do see some kind of mesoscale-banding with this event, which will mainly enhance snow totals along and southeast of U.S. 24.
Not only this, but strong, jet-streak circulations will likely enhance the development of moderate-heavy snow bands. The 18z NAM also showed that a small, macro-scale jet over C. Indiana will "couple" with a jet-streak over Canada, producing intense upward vertical motion in between [this happens due to the fact that strong upward motion usually occurs in the left-exit region and the right-entrance region of jet-streaks, and when these are interposed on each other, they enhance dynamics greatly]. If this were to occur, we would expect the development of heavier periods of snow during the day Saturday or in the early morning hours. This will be yet another factor in my snowfall forecast.
But for now, I'm sticking with the 3-5"/4-6" forecast, as it appears to be reasonable at this time.
You make a great point the storm will not interrupt school.
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