Good morning from Southern Connecticut Weather.
We have our first map of the season for a minor snow event that's coming to the state. While some precipitation may start late Wednesday, the bulk of the event will occur on Thursday, possibly impacting the morning commute. The storm will be followed with a breezy and frigid (by early December standards) Friday.
We have our first map of the season for a minor snow event that's coming to the state. While some precipitation may start late Wednesday, the bulk of the event will occur on Thursday, possibly impacting the morning commute. The storm will be followed with a breezy and frigid (by early December standards) Friday.
Above: Our SCW forecast map. This is a minor event. For most, a coating to an inch or two is likely. For our hill towns in NW and NE CT, 1-3" looks more likely, with some isolated areas getting 4" if everything breaks right for them. Along part of SE CT, it looks as if temperatures will be too warm for much if any accumulation, though snowflakes are still likely.
Timing
The timing looks pretty straightforward for this one. Our clipper is currently over central Canada and is moving east. Today looks like another colder than normal but quiet day, with increasing clouds later in the day as the clipper approaches the region. Precipitation may start as early as 8-10pm across the state and because of the track of the storm, it may start out as rain, particularly in coastal and eastern CT. The expectation is that overnight we see a gradual change over to snow for most, especially inland. Some of that snow could be moderate at times, especially in hill towns, leading to our accumulations.
The Thursday morning commute does look to be impacted as bouts of precipitation continue into the morning hours on Thursday. By the afternoon, the storm will be mostly over, with some scattered rain or snow showers gradually ending. This will be a windy storm, with wind advisories up for each of the southern four counties. The wind should die down by Thursday night, with breezy conditions possible Friday.
Timing
The timing looks pretty straightforward for this one. Our clipper is currently over central Canada and is moving east. Today looks like another colder than normal but quiet day, with increasing clouds later in the day as the clipper approaches the region. Precipitation may start as early as 8-10pm across the state and because of the track of the storm, it may start out as rain, particularly in coastal and eastern CT. The expectation is that overnight we see a gradual change over to snow for most, especially inland. Some of that snow could be moderate at times, especially in hill towns, leading to our accumulations.
The Thursday morning commute does look to be impacted as bouts of precipitation continue into the morning hours on Thursday. By the afternoon, the storm will be mostly over, with some scattered rain or snow showers gradually ending. This will be a windy storm, with wind advisories up for each of the southern four counties. The wind should die down by Thursday night, with breezy conditions possible Friday.
Above: the latest 12km NAM depicting the evolution of the storm. There are a number of factors that influence our snow forecast below.
Snow Accumulation
As you see in the map above, this is a minor event. For winter weather lovers, that's probably frustrating, as usually we do not have precipitation type issues for a clipper. There are a few things that have me leaning more conservative. First and foremost, the track of the clipper puts us in a southerly and southwest flow. If this were the kind of clipper that tracked under the region, we'd be in much better shape for all snow statewide. However, the clipper will track to our north, giving us that relatively warm wind direction. As a result, temperatures at the surface look marginal.
For places like the coastline and CT River Valley, you know what that means. Snow may fall because it's cold enough aloft, but it may struggle to accumulate because the surface is too warm. The timing with snow falling overnight helps, which is why I think a measurable coating is likely for most. The further inland you are, the more likely you end up with a higher total.
The other significant factor is the nature of the system itself. It's not terribly dynamic, but may have enough "juice" to allow for minor but more meaningful accumulation in our hill towns, especially in eastern CT where the precipitation shield may be more likely to blossom and a southwest flow could enhance lift in the NE hills. If there's a place that could overperform some and top out with an isolated 4 or even 5" total, it's in this zone. That said, if this comes in weaker, accumulations will be lower in the forecast range.
I would say that there's a 60% chance that we fall within our range on balance, with a 25% chance of a widespread bust (less snow than forecast), and 15% chance of a widespread boom (more snow than forecast).
It's important to remember that although we can get significant storms around this time of the month, climatology overall is still pretty hostile, especially at the coast. It's not until mid to late month that conditions for snow become much more prevalent historically.
Snow Accumulation
As you see in the map above, this is a minor event. For winter weather lovers, that's probably frustrating, as usually we do not have precipitation type issues for a clipper. There are a few things that have me leaning more conservative. First and foremost, the track of the clipper puts us in a southerly and southwest flow. If this were the kind of clipper that tracked under the region, we'd be in much better shape for all snow statewide. However, the clipper will track to our north, giving us that relatively warm wind direction. As a result, temperatures at the surface look marginal.
For places like the coastline and CT River Valley, you know what that means. Snow may fall because it's cold enough aloft, but it may struggle to accumulate because the surface is too warm. The timing with snow falling overnight helps, which is why I think a measurable coating is likely for most. The further inland you are, the more likely you end up with a higher total.
The other significant factor is the nature of the system itself. It's not terribly dynamic, but may have enough "juice" to allow for minor but more meaningful accumulation in our hill towns, especially in eastern CT where the precipitation shield may be more likely to blossom and a southwest flow could enhance lift in the NE hills. If there's a place that could overperform some and top out with an isolated 4 or even 5" total, it's in this zone. That said, if this comes in weaker, accumulations will be lower in the forecast range.
I would say that there's a 60% chance that we fall within our range on balance, with a 25% chance of a widespread bust (less snow than forecast), and 15% chance of a widespread boom (more snow than forecast).
It's important to remember that although we can get significant storms around this time of the month, climatology overall is still pretty hostile, especially at the coast. It's not until mid to late month that conditions for snow become much more prevalent historically.
Above: the latest GFS depiction of the storm. The temperatures just look too marginal for most for a significant event, though even here much of the state does get measurable snow verbatim. Note that the GFS does keep some precipitation around Thursday afternoon, which is why I think rain/snow showers will still be around though less impactful.
Impact
This looks like a minor event overall. For interior CT, especially the hill towns, the impact may be a touch higher given the timing of the snow. We also have to watch for isolated to scattered power outages due to wind. That said, because the leaves are down, widespread outages and tree damage looks unlikely, especially since we're not expecting major accumulation.
It's important to note that the majority of car collisions happen under these very conditions--with minor snowfalls. People overestimate their ability to drive in the snow. Give yourself plenty of time to travel on your Thursday morning commute, and during the evening commute as any water on the roads could refreeze. I do not expect major airline issues with delays or cancellations.
In the wake of the storm, Friday looks very cold. Both the Euro and GFS has most of the state below freezing through the day. The Euro even toys with temperatures struggling to escape the low 20s for many inland. With breezy conditions possible, expect even colder wind chills.
Impact
This looks like a minor event overall. For interior CT, especially the hill towns, the impact may be a touch higher given the timing of the snow. We also have to watch for isolated to scattered power outages due to wind. That said, because the leaves are down, widespread outages and tree damage looks unlikely, especially since we're not expecting major accumulation.
It's important to note that the majority of car collisions happen under these very conditions--with minor snowfalls. People overestimate their ability to drive in the snow. Give yourself plenty of time to travel on your Thursday morning commute, and during the evening commute as any water on the roads could refreeze. I do not expect major airline issues with delays or cancellations.
In the wake of the storm, Friday looks very cold. Both the Euro and GFS has most of the state below freezing through the day. The Euro even toys with temperatures struggling to escape the low 20s for many inland. With breezy conditions possible, expect even colder wind chills.
Above: GFS temperatures Friday afternoon.
Below: Euro temperatures Friday afternoon.
Below: Euro temperatures Friday afternoon.
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Thank you for reading SCW.
-DB
Thank you for reading SCW.
-DB
