Good evening from Southern Connecticut Weather.
Busy times.
Tonight we're dealing with a close scrape from a storm to the south (Storm One) and the second storm this week (Storm Two) is already on its heels. A mixed bag is on tap for our Thursday, and because of the timing there is likely to be some impact. Storm Three is waiting this weekend. Let's dive in.
Busy times.
Tonight we're dealing with a close scrape from a storm to the south (Storm One) and the second storm this week (Storm Two) is already on its heels. A mixed bag is on tap for our Thursday, and because of the timing there is likely to be some impact. Storm Three is waiting this weekend. Let's dive in.
Above: a snapshot of the high resolution NAM, showing mixed precipitation in northern Connecticut and rain in southern CT around 4am Thursday morning.
Storm Two (Late Wednesday-Thursday)
In this pattern you should expect some of everything: hits, misses, snow, rain, and mixed precipitation. Literally. The fast flow in the atmosphere moves storms along very quickly, while the oscillating temperature gradient between warm and cold makes precipitation type for each system tricky.
Storm Two has trended weaker over the last few days, which has a big impact on conditions and impact. If it were stronger, we'd likely be able to hold more cold in place as warm air tried to erode the cold, but with a weaker storm and lighter precipitation, we can't get enough cooling to hold off the rain.
There will still be enough cold late tomorrow for things to start off as snow, but that snow will be light and quickly change over. In southern CT, it will quickly go from snow (a coating) to mix to rain, while inland areas will hold onto mixing a little longer on Thursday.
The NAM below depicts this well, showing a period of snow starting between approximately 8-10pm Wednesday night, followed by a change to mix and then rain Thursday morning.
In this pattern you should expect some of everything: hits, misses, snow, rain, and mixed precipitation. Literally. The fast flow in the atmosphere moves storms along very quickly, while the oscillating temperature gradient between warm and cold makes precipitation type for each system tricky.
Storm Two has trended weaker over the last few days, which has a big impact on conditions and impact. If it were stronger, we'd likely be able to hold more cold in place as warm air tried to erode the cold, but with a weaker storm and lighter precipitation, we can't get enough cooling to hold off the rain.
There will still be enough cold late tomorrow for things to start off as snow, but that snow will be light and quickly change over. In southern CT, it will quickly go from snow (a coating) to mix to rain, while inland areas will hold onto mixing a little longer on Thursday.
The NAM below depicts this well, showing a period of snow starting between approximately 8-10pm Wednesday night, followed by a change to mix and then rain Thursday morning.
Because of the timing, this weak storm will have some impact, especially inland. Unlike last week, the cold is unlikely to hang on as long.
For southern Connecticut, expect a coating of snow and a light glaze of ice Wednesday night into early Thursday. By sunrise it will be a plain rain. As a result, the impact looks low, and while widespread delays are possible I do not think they are likely.
For northern Connecticut, we could see a coating to an inch or isolated two spot before a glaze of ice. While some guidance shows a change to rain, it's possible that a dry slot moves in before there is meaningful rainfall. Because mixing could continue past sunrise in northern CT, widespread delays look likely, and cancellations are possible.
This is a fast mover, so the PM commute although wet, shouldn't be too bad.
For southern Connecticut, expect a coating of snow and a light glaze of ice Wednesday night into early Thursday. By sunrise it will be a plain rain. As a result, the impact looks low, and while widespread delays are possible I do not think they are likely.
For northern Connecticut, we could see a coating to an inch or isolated two spot before a glaze of ice. While some guidance shows a change to rain, it's possible that a dry slot moves in before there is meaningful rainfall. Because mixing could continue past sunrise in northern CT, widespread delays look likely, and cancellations are possible.
This is a fast mover, so the PM commute although wet, shouldn't be too bad.
Storm Three (Saturday-Sunday)
The final storm of the week continues to have the biggest potential, but there's a lot of uncertainty over whether it will be a significant rain event (1"+) or a wintry storm.
This one is tricky, and it's a lot about timing. A piece of Arctic air is trying to move toward the region as the weekend storm develops. Recent guidance has backed off a significant cold press leading to another mixed bag to rain system. There is a lot that can still change with this, so it's not worth going into too much detail yet until some of the major features are more stable, but this looks to be a longer duration storm as a follow up wave tries to develop along the temperature gradient.
With a colder press, the gradient and thus the low would sag further south, bringing significant snow and/or ice. Without that cold press from the polar vortex, the temperature gradient is further north, and the storm effectively cuts to our west, bringing heavy rain Saturday and Sunday.
In terms of timing, it looks like onset wants to speed up. Right now, we're looking at snow breaking out early Saturday afternoon, with precipitation likely lasting through Sunday as the follow up wave develops. There are still significant differences between the GFS and Euro. At this time, I think this one brings a snow to mix to rain event.
GFS, which is much more wintry with snow and potentially significant ice.
The final storm of the week continues to have the biggest potential, but there's a lot of uncertainty over whether it will be a significant rain event (1"+) or a wintry storm.
This one is tricky, and it's a lot about timing. A piece of Arctic air is trying to move toward the region as the weekend storm develops. Recent guidance has backed off a significant cold press leading to another mixed bag to rain system. There is a lot that can still change with this, so it's not worth going into too much detail yet until some of the major features are more stable, but this looks to be a longer duration storm as a follow up wave tries to develop along the temperature gradient.
With a colder press, the gradient and thus the low would sag further south, bringing significant snow and/or ice. Without that cold press from the polar vortex, the temperature gradient is further north, and the storm effectively cuts to our west, bringing heavy rain Saturday and Sunday.
In terms of timing, it looks like onset wants to speed up. Right now, we're looking at snow breaking out early Saturday afternoon, with precipitation likely lasting through Sunday as the follow up wave develops. There are still significant differences between the GFS and Euro. At this time, I think this one brings a snow to mix to rain event.
GFS, which is much more wintry with snow and potentially significant ice.
The Euro on the other hand goes from snow to significant amounts of rain during the period.
There's still a ton to sort out with the weekend. A storm is likely and we will likely have some snow, but how much snow before going to ice or possible rain remains highly uncertain. Stay tuned.
As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.
Thank you for reading SCW.
-DB
As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.
Thank you for reading SCW.
-DB
