Good evening from Southern Connecticut Weather.
Winter weather advisories are up once again for all of Connecticut as the latest storm in our extremely active pattern approaches. This one, like most of the others, will be a mixed bag system, with snow, sleet, freezing rain, and rain for the state over most of the weekend. Let's get right to it. There's a lot to discuss, including a look at big wind potential Monday, another Arctic blast, and the next potential storm in the pipeline.
Winter weather advisories are up once again for all of Connecticut as the latest storm in our extremely active pattern approaches. This one, like most of the others, will be a mixed bag system, with snow, sleet, freezing rain, and rain for the state over most of the weekend. Let's get right to it. There's a lot to discuss, including a look at big wind potential Monday, another Arctic blast, and the next potential storm in the pipeline.
Above: the snow and ice map for our upcoming storm. For southern CT, I expect a general 1-3" of snow and sleet, followed by a glaze of ice especially inland. For northern CT it gets more tricky, with 2-5" of snow and sleet expected and a glaze of ice for most. In NW CT, really most of Litchfield County, there is a greater risk of modest ice accumulation via freezing rain on Sunday.
Overall Setup
We've been watching this storm closely the last few days, and while the general setup is now relatively straightforward, the devil is in the details.
Unlike our last few systems of middling strength, this is a big dog. A low pressure system will eject from the south, and rapidly intensify as it tracks northeast. Because there is no real Atlantic blocking to shunt it out to sea up under our region, with will cut to our west as it intensifies. That means we rain eventually.
However, there is a relatively deep level of cold air in place, and that will ensure that the front end of the system will produce snow and ice. Importantly, this storm will try to spawn a mesolow off the coast that would lock in colder air as precipitation runs over the region, but that is something we will need to watch for as the storm evolves. Rather than the original thought of two separate waves this weekend, there's really only one big storm. Note the surface pressure in the 975mb range over near Buffalo and the expanse of the snow on the NW side of the low. This is a sprawling and powerful storm, that will influence the wind potential after it departs Monday and drag in our latest Arctic blast.
The GFS below illustrates the storm evolution and the cold air advection Monday morning.
We've been watching this storm closely the last few days, and while the general setup is now relatively straightforward, the devil is in the details.
Unlike our last few systems of middling strength, this is a big dog. A low pressure system will eject from the south, and rapidly intensify as it tracks northeast. Because there is no real Atlantic blocking to shunt it out to sea up under our region, with will cut to our west as it intensifies. That means we rain eventually.
However, there is a relatively deep level of cold air in place, and that will ensure that the front end of the system will produce snow and ice. Importantly, this storm will try to spawn a mesolow off the coast that would lock in colder air as precipitation runs over the region, but that is something we will need to watch for as the storm evolves. Rather than the original thought of two separate waves this weekend, there's really only one big storm. Note the surface pressure in the 975mb range over near Buffalo and the expanse of the snow on the NW side of the low. This is a sprawling and powerful storm, that will influence the wind potential after it departs Monday and drag in our latest Arctic blast.
The GFS below illustrates the storm evolution and the cold air advection Monday morning.
The Forecast
Timing
This is trickier than I'd like because there is a bit of a discrepancy in the high resolution models for when this starts. Tomorrow morning and early afternoon look fine statewide. If you have morning and even early afternoon activities or travel plans, they will be fine. However, snow will break out statewide tomorrow afternoon. I think we see snow start out light for the state from west to east between approximately 3-7pm. The earliest start time will be in western CT, with the start of the storm during the middle part of that time frame in central CT, and latter part of that time frame in eastern CT.
The snow will be moderate at times, and given the cold that will be in place tomorrow expect road conditions to deteriorate as the snow continues. It will snow statewide most of tomorrow. As the cold air aloft erodes, we will see the mix line start to creep into CT. In southwest CT, it will happen the earliest, with a flip from snow to sleet likely between about 10pm to midnight. Once this mix line starts showing up, it will blast its way through much of southern CT, turning most of southern CT to rain by early Sunday morning.
However, for northern CT, that mixing will be hard to dislodge during the early morning hours. That will give the area an extended period of sleet and then potentially freezing rain. In NW CT especially, surface cold will be hard to dislodge, so there's a chance icing continues into the day Sunday there, and across much of northern CT if the mesolow develops fast enough to lock in the cold for longer.
At any rate, warmth eventually wins with this storm for most if not all of the state. By Sunday afternoon and night we will likely have periods of moderate to heavy rain moving through the state until the storm passes and winds start to ramp up in its wake. Monday will be clear, but it will be very windy.
Snow & Ice Accumulation
If you look at the image below, this is basically how the storm will play out over time.
We will start with cold air at the surface and aloft across the entire state. That's why we will start off as snow. Over time tomorrow, warm air aloft will erode the cold, changing us to sleet. As more warmth moves in as the storm intensifies to our west, then we will see freezing rain. The surface cold will be hardest to dislodge in northern CT, which is why freezing rain will likely last longer here than in southern CT. Once the warmth has overwhelmed the entire column, we rain.
Timing
This is trickier than I'd like because there is a bit of a discrepancy in the high resolution models for when this starts. Tomorrow morning and early afternoon look fine statewide. If you have morning and even early afternoon activities or travel plans, they will be fine. However, snow will break out statewide tomorrow afternoon. I think we see snow start out light for the state from west to east between approximately 3-7pm. The earliest start time will be in western CT, with the start of the storm during the middle part of that time frame in central CT, and latter part of that time frame in eastern CT.
The snow will be moderate at times, and given the cold that will be in place tomorrow expect road conditions to deteriorate as the snow continues. It will snow statewide most of tomorrow. As the cold air aloft erodes, we will see the mix line start to creep into CT. In southwest CT, it will happen the earliest, with a flip from snow to sleet likely between about 10pm to midnight. Once this mix line starts showing up, it will blast its way through much of southern CT, turning most of southern CT to rain by early Sunday morning.
However, for northern CT, that mixing will be hard to dislodge during the early morning hours. That will give the area an extended period of sleet and then potentially freezing rain. In NW CT especially, surface cold will be hard to dislodge, so there's a chance icing continues into the day Sunday there, and across much of northern CT if the mesolow develops fast enough to lock in the cold for longer.
At any rate, warmth eventually wins with this storm for most if not all of the state. By Sunday afternoon and night we will likely have periods of moderate to heavy rain moving through the state until the storm passes and winds start to ramp up in its wake. Monday will be clear, but it will be very windy.
Snow & Ice Accumulation
If you look at the image below, this is basically how the storm will play out over time.
We will start with cold air at the surface and aloft across the entire state. That's why we will start off as snow. Over time tomorrow, warm air aloft will erode the cold, changing us to sleet. As more warmth moves in as the storm intensifies to our west, then we will see freezing rain. The surface cold will be hardest to dislodge in northern CT, which is why freezing rain will likely last longer here than in southern CT. Once the warmth has overwhelmed the entire column, we rain.
This makes the snow and ice accumulation forecast tricky. Along the coast, you honestly want more snow than ice, which means you want heavy enough precipitation to keep the column cool as long as possible before warmth arrives.
For southern CT, I anticipate a general 1-3" of snow and sleet, along with a glaze of freezing rain before a flip to rain. The lowest snow amounts are likely in coastal SW and SE CT, with more snow and sleet the further inland you are.
For northern CT, the guidance is all over the place. My best call is a general 2-5". I doubt many see 5". I want a high ceiling for if this trends colder. I think most likely land in the 2-4" zone.
It's really important to note that I'm intentional in setting these ceilings and floors. It's not going to be a bust if most of the state is 1-2" of snow--that would likely mean that there's fairly substantial icing in the form of sleet (which accumulates much less efficiently like snow) and freezing rain. The ice is the story for this storm.
Less snow and more ice as I described above is probably the highest impact and worst case scenario. It is on the table, but I expect more cold in place for more measurable snow and some ice.
Below is the latest high resolution NAM depiction, showing the difficulty in getting the cold air in CT totally eroded. There will be places in southern CT on Sunday that rocket their way into the 40s, while parts of northern CT will be struggling to cross the freezing mark, especially early.
This is a very tricky setup.
For southern CT, I anticipate a general 1-3" of snow and sleet, along with a glaze of freezing rain before a flip to rain. The lowest snow amounts are likely in coastal SW and SE CT, with more snow and sleet the further inland you are.
For northern CT, the guidance is all over the place. My best call is a general 2-5". I doubt many see 5". I want a high ceiling for if this trends colder. I think most likely land in the 2-4" zone.
It's really important to note that I'm intentional in setting these ceilings and floors. It's not going to be a bust if most of the state is 1-2" of snow--that would likely mean that there's fairly substantial icing in the form of sleet (which accumulates much less efficiently like snow) and freezing rain. The ice is the story for this storm.
Less snow and more ice as I described above is probably the highest impact and worst case scenario. It is on the table, but I expect more cold in place for more measurable snow and some ice.
Below is the latest high resolution NAM depiction, showing the difficulty in getting the cold air in CT totally eroded. There will be places in southern CT on Sunday that rocket their way into the 40s, while parts of northern CT will be struggling to cross the freezing mark, especially early.
This is a very tricky setup.
Wind & Power Outages
Overall, being on the warm side of this storm isn't going to cause a lot of wind issues early. In fact, for most of the storm I'm not expecting significant wind. However, in the wake of the storm we are likely to get a significant period of wind on Monday. That's going to be discussed later since it's post storm.
With possible icing in interior CT however, wind on Monday will be something to watch. The ice by itself doesn't look to be major, but there could be some isolated to scattered outages on Sunday, and more scattered outages on Monday depending on whether we can get the higher winds to verify.
Overall Impact
This is a high impact event. To be clear--it's not a let's panic and go get bread and milk storm, but it's high impact because most events will likely be canceled for later Saturday and into Sunday, even though it'll likely be fairly warm in southern CT eventually. Flights will likely get delayed between Saturday evening and Sunday early afternoon.
The snow by itself isn't bad, but the combination of snow (which could be moderate at times statewide on Saturday), sleet and freezing rain especially inland, and the prospect of heavy rain and snowmelt on Sunday that could cause some localized flooding issues, makes this a messy event.
Road conditions will not be great for northern CT on late Saturday afternoon/evening into much of Sunday. In southern CT, road conditions will not be great Saturday afternoon/evening into Sunday morning in terms of snow/ice. Wet roads will be a thing late Sunday morning and through the evening.
Because of the timing of the storm and winds after, there is the chance of widespread delays Monday morning, but it's a little early to lock that in. I just need to note it here because the potential is there.
Overall, being on the warm side of this storm isn't going to cause a lot of wind issues early. In fact, for most of the storm I'm not expecting significant wind. However, in the wake of the storm we are likely to get a significant period of wind on Monday. That's going to be discussed later since it's post storm.
With possible icing in interior CT however, wind on Monday will be something to watch. The ice by itself doesn't look to be major, but there could be some isolated to scattered outages on Sunday, and more scattered outages on Monday depending on whether we can get the higher winds to verify.
Overall Impact
This is a high impact event. To be clear--it's not a let's panic and go get bread and milk storm, but it's high impact because most events will likely be canceled for later Saturday and into Sunday, even though it'll likely be fairly warm in southern CT eventually. Flights will likely get delayed between Saturday evening and Sunday early afternoon.
The snow by itself isn't bad, but the combination of snow (which could be moderate at times statewide on Saturday), sleet and freezing rain especially inland, and the prospect of heavy rain and snowmelt on Sunday that could cause some localized flooding issues, makes this a messy event.
Road conditions will not be great for northern CT on late Saturday afternoon/evening into much of Sunday. In southern CT, road conditions will not be great Saturday afternoon/evening into Sunday morning in terms of snow/ice. Wet roads will be a thing late Sunday morning and through the evening.
Because of the timing of the storm and winds after, there is the chance of widespread delays Monday morning, but it's a little early to lock that in. I just need to note it here because the potential is there.
Looking Ahead
I will do this very quickly, since the weekend storm is the main focus. We're nowhere close to being done with this active wintry pattern. It's likely to last until at least early March. There is no early spring likely this year.
As I mentioned above, Monday we are likely to see a very windy day in the wake of our storm. Right now, I think we see wind advisories for gusts of 45-50mph statewide, but there is a signal for greater wind potential on Monday. If that happens, power outages will become more likely. Stay tuned to for additional updates as that comes into greater focus.
One thing is a guarantee: we get Arctic cold in the wake of this big weekend storm. Expect high temperatures well below normal, with the chance we string together some days below freezing. This time of year, temperatures start to rebound. Believe it or not, the average high/low temperature in Hartford in mid February is 38/20, while it's 40/25 in Bridgeport.
The Arctic blast will be much worse to our west, but it'll be plenty cold here. Below is a European ensemble 5 day averaged temperature departure next week.
I will do this very quickly, since the weekend storm is the main focus. We're nowhere close to being done with this active wintry pattern. It's likely to last until at least early March. There is no early spring likely this year.
As I mentioned above, Monday we are likely to see a very windy day in the wake of our storm. Right now, I think we see wind advisories for gusts of 45-50mph statewide, but there is a signal for greater wind potential on Monday. If that happens, power outages will become more likely. Stay tuned to for additional updates as that comes into greater focus.
One thing is a guarantee: we get Arctic cold in the wake of this big weekend storm. Expect high temperatures well below normal, with the chance we string together some days below freezing. This time of year, temperatures start to rebound. Believe it or not, the average high/low temperature in Hartford in mid February is 38/20, while it's 40/25 in Bridgeport.
The Arctic blast will be much worse to our west, but it'll be plenty cold here. Below is a European ensemble 5 day averaged temperature departure next week.
There will be plenty of cold, which will lead us to the next storm in the pipeline.
There is zero reason to get excited about or dread a possible storm next week. At this time, we do have higher than usual confidence that something will develop. Because there is going to be cold air in place and likely blocking in the Atlantic, we know it is highly unlikely to cut like this weekend storm. We have moderate confidence that the timing for a storm would be late Wednesday or Thursday. We do not know track and storm evolution. This could easily miss because of a poorly timed phase--just like that blizzard we missed out on a month ago. This could be a messy phase that brings us another modest snowfall. It could be a big dog blizzard. There's no real reason to do anything other than look at next week with a casual eye and avoid the hype on social media and elsewhere. Let's see where we are Sunday before taking anything related to next week seriously.
There is zero reason to get excited about or dread a possible storm next week. At this time, we do have higher than usual confidence that something will develop. Because there is going to be cold air in place and likely blocking in the Atlantic, we know it is highly unlikely to cut like this weekend storm. We have moderate confidence that the timing for a storm would be late Wednesday or Thursday. We do not know track and storm evolution. This could easily miss because of a poorly timed phase--just like that blizzard we missed out on a month ago. This could be a messy phase that brings us another modest snowfall. It could be a big dog blizzard. There's no real reason to do anything other than look at next week with a casual eye and avoid the hype on social media and elsewhere. Let's see where we are Sunday before taking anything related to next week seriously.
Above: the GFS from this afternoon showing a miss next week.
Below: the Euro showing a messy phase leading to a modest storm next week.
Below: the Euro showing a messy phase leading to a modest storm next week.
Nothing to be riled up about. At all.
Yet.
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
Yet.
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
