After a "brief" hiatus from extremely cold, snowy and blustery weather, our exceptional winter has brought another round of weather that only seems to be suitable for regions north of the Arctic circle [not literally, but you get my point]. After seeing a full weak with temperatures slightly above normal along with rainfall, temperatures have drastically fallen with temperatures below freezing for nearly a week now [discounting Sunday-night into Monday when temperatures rose above freezing for a brief time]. Not only this, but temperatures have fallen below zero for the past several nights, and along with strong, gusty winds at times has lead to wind-chills far below zero on all three nights. Today, breezy conditions have caused another problem; intense blowing and drifting snow. This has lead to near "ground-blizzard" conditions across the region, mainly in the rural areas and has made some roads nearly impassable.
After all this crazy weather, you'd think that Mother Nature would be done by now. I'm here to bring you the solemn news that this is not so. At least two more rounds of light-moderate snowfall is expected over the next three days, followed by a longer period of bitterly cold temperatures and biting Arctic winds. The first round of snow begins tonight, with the potential for 2-4" likely across most of the area [potentially more depending upon if lift/dynamics is focused more in the dendritic-snow growth layer] through Saturday morning. Although I am not expecting heavy snowfall rates [it is possible that snowfall rates could become moderate to heavy in some areas, but it is unlikely at this time, and if it does, it will be brief, small periods of it], I do expect that extremely windy conditions will lead to incredibly low visibilities, with possible whiteout conditions at times. At the same time, the good news is that temperatures will be rising all night, to a peak of 22 or 23 by the early morning hours. However, this will not be enough to affect road conditions until windy conditions subside.
There are several potential factors that could affect snowfall amounts tonight, including:
1.) Moisture- an unusual surge of moisture will affect regions along the front, which will aid in precipitation/snowfall development. Depending upon how much moisture interacts with the DGZ layer [-10 to -18 C temperature range in the mid-levels of the atmosphere], this could enhance snowfall amounts in some parts of the area.
2.) Dynamics- Upper-level forcing could be rather significant tonight, especially as the main wave dives southward towards the region. This in combination with some jet-streak dynamics and WAA will allow light-moderate snow to develop across the area. If dynamics become more focused in the DGZ region of the atmosphere, we could see more efficient snowfall production and thus higher snowfall amounts.
While there are a few other minor issues, they won't have near the effect on snowfall tonight. For instance, if we see less WAA, but colder mid-level temperatures, we will see higher snow ratios, but less overall moisture/forcing. However, if we see slightly warmer mid-level temperatures, we will see more moisture/forcing but lesser snow ratios. At this point, I'm leaning towards slightly higher mid-level temperatures, which could aid in heavier snow totals, even though snow ratios could be a bit lower [around 15:1 or 16:1]. Also, given the fact that clipper systems tend to over-perform on many occasions, I'm willing to bet on 3-4" of snow occurring in some areas.
After the snowfall begins to wane on Saturday, gusty winds behind the front will lead to more blowing and drifting snowfall, as well as falling temperatures. By the end of the day, temperatures will be below 10 degrees again, with lows around 0 Saturday night.
By Sunday, there is still some disagreement between models on precip. amount and heaviest snowfall placement, but at this point it appears that it will be a similar event to what is happening tonight, but perhaps with stronger dynamics and slightly more moisture. For this reason, I believe Sunday's event will be more along the lines of 2-4"/3-5" instead of 1-3"/2-4". This is especially the case if the mid-level instability that is expected can overspread parts of the area, causing mesoscale-banding. However, there is still some uncertainty, especially given the fact that snow-ratios will likely be lower than tonight [around 13:1 or 14:1]. Even so, gusty winds are still expected, leading to more blowing and drifting snowfall. Temperatures will fall throughout the night Sunday into the lower single-digits. Highs on Monday behind the cold front will barely make it above this low, with temperatures falling well below-zero Monday night. By Tuesday and Wednesday, temperatures could be even colder. Tuesday it doesn't look like the area will make it above 0 [some models are indicating highs around -5 to -10 below], with Tuesday-night lows around -10 to -15 [some models are indicating that temperatures could drop below -20, which isn't out of the realm of possibility]. By Wednesday and Thursday, temperatures begin warming up again, with only a slow moderation likely. Given model discrepancy at this point, it appears that the warmest temperatures will get by Thursday is about 19 degrees.
I'll have more updates later.
After all this crazy weather, you'd think that Mother Nature would be done by now. I'm here to bring you the solemn news that this is not so. At least two more rounds of light-moderate snowfall is expected over the next three days, followed by a longer period of bitterly cold temperatures and biting Arctic winds. The first round of snow begins tonight, with the potential for 2-4" likely across most of the area [potentially more depending upon if lift/dynamics is focused more in the dendritic-snow growth layer] through Saturday morning. Although I am not expecting heavy snowfall rates [it is possible that snowfall rates could become moderate to heavy in some areas, but it is unlikely at this time, and if it does, it will be brief, small periods of it], I do expect that extremely windy conditions will lead to incredibly low visibilities, with possible whiteout conditions at times. At the same time, the good news is that temperatures will be rising all night, to a peak of 22 or 23 by the early morning hours. However, this will not be enough to affect road conditions until windy conditions subside.
There are several potential factors that could affect snowfall amounts tonight, including:
1.) Moisture- an unusual surge of moisture will affect regions along the front, which will aid in precipitation/snowfall development. Depending upon how much moisture interacts with the DGZ layer [-10 to -18 C temperature range in the mid-levels of the atmosphere], this could enhance snowfall amounts in some parts of the area.
2.) Dynamics- Upper-level forcing could be rather significant tonight, especially as the main wave dives southward towards the region. This in combination with some jet-streak dynamics and WAA will allow light-moderate snow to develop across the area. If dynamics become more focused in the DGZ region of the atmosphere, we could see more efficient snowfall production and thus higher snowfall amounts.
While there are a few other minor issues, they won't have near the effect on snowfall tonight. For instance, if we see less WAA, but colder mid-level temperatures, we will see higher snow ratios, but less overall moisture/forcing. However, if we see slightly warmer mid-level temperatures, we will see more moisture/forcing but lesser snow ratios. At this point, I'm leaning towards slightly higher mid-level temperatures, which could aid in heavier snow totals, even though snow ratios could be a bit lower [around 15:1 or 16:1]. Also, given the fact that clipper systems tend to over-perform on many occasions, I'm willing to bet on 3-4" of snow occurring in some areas.
After the snowfall begins to wane on Saturday, gusty winds behind the front will lead to more blowing and drifting snowfall, as well as falling temperatures. By the end of the day, temperatures will be below 10 degrees again, with lows around 0 Saturday night.
By Sunday, there is still some disagreement between models on precip. amount and heaviest snowfall placement, but at this point it appears that it will be a similar event to what is happening tonight, but perhaps with stronger dynamics and slightly more moisture. For this reason, I believe Sunday's event will be more along the lines of 2-4"/3-5" instead of 1-3"/2-4". This is especially the case if the mid-level instability that is expected can overspread parts of the area, causing mesoscale-banding. However, there is still some uncertainty, especially given the fact that snow-ratios will likely be lower than tonight [around 13:1 or 14:1]. Even so, gusty winds are still expected, leading to more blowing and drifting snowfall. Temperatures will fall throughout the night Sunday into the lower single-digits. Highs on Monday behind the cold front will barely make it above this low, with temperatures falling well below-zero Monday night. By Tuesday and Wednesday, temperatures could be even colder. Tuesday it doesn't look like the area will make it above 0 [some models are indicating highs around -5 to -10 below], with Tuesday-night lows around -10 to -15 [some models are indicating that temperatures could drop below -20, which isn't out of the realm of possibility]. By Wednesday and Thursday, temperatures begin warming up again, with only a slow moderation likely. Given model discrepancy at this point, it appears that the warmest temperatures will get by Thursday is about 19 degrees.
I'll have more updates later.
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