Good evening from Southern Connecticut Weather.
A major winter storm is taking shape to our south, and is set to impact the entire state tomorrow into early Thursday. This discussion will try to be concise and to the point, focusing on impacts and remaining uncertainty in the forecast.
We are taking the numbers up for the western portion of the state. We are taking the numbers down just a tad in eastern portions of the state due to continued uncertainty over dry slotting and the rain/snow line.
A major winter storm is taking shape to our south, and is set to impact the entire state tomorrow into early Thursday. This discussion will try to be concise and to the point, focusing on impacts and remaining uncertainty in the forecast.
We are taking the numbers up for the western portion of the state. We are taking the numbers down just a tad in eastern portions of the state due to continued uncertainty over dry slotting and the rain/snow line.
The Setup
The overall meteorology behind the development and progression of the system has not changed. We have a fairly difficult setup where a low moves off the Mid-Atlantic coast as another piece of energy digs from the northwest. This interaction plays a role in the overall track of the low, which impacts temperature profiles in the atmosphere.
Today, the guidance has more or less remained the same with these features, but we’ve seen how ticks west or east of the low impact snow totals, with further west tracks introducing more warmth into the state and further east tracks keeping much of the state solidly in a snow profile. Small shifts will mean a lot, as I’ll explain below.
In terms of dynamics, this looks to be another rapidly intensifying storm, but not at the level of our most recent event. As a result, we can expect a period of moderate to heavy snow across much of the state and gusty winds.
In anticipation of the event, the National Weather Service has issued winter storm warnings for all of the state, with the exception of coastal Middlesex and New London Counties.
The overall meteorology behind the development and progression of the system has not changed. We have a fairly difficult setup where a low moves off the Mid-Atlantic coast as another piece of energy digs from the northwest. This interaction plays a role in the overall track of the low, which impacts temperature profiles in the atmosphere.
Today, the guidance has more or less remained the same with these features, but we’ve seen how ticks west or east of the low impact snow totals, with further west tracks introducing more warmth into the state and further east tracks keeping much of the state solidly in a snow profile. Small shifts will mean a lot, as I’ll explain below.
In terms of dynamics, this looks to be another rapidly intensifying storm, but not at the level of our most recent event. As a result, we can expect a period of moderate to heavy snow across much of the state and gusty winds.
In anticipation of the event, the National Weather Service has issued winter storm warnings for all of the state, with the exception of coastal Middlesex and New London Counties.
Overall Impact
Our graphic has not changed from our first call yesterday. We expect a high impact event statewide. In fact, school closures and parking bans are already being announced. Let’s go in more detail with each.
Snowfall Accumulation
As you saw above, we’re upping the numbers slightly. For me, this is less guidance driven and based more on higher confidence of higher totals in western Connecticut. For the central portion of the state, I think our original 6-12 call works. Everyone should keep in mind that not everyone is going to get the upper end of these forecast totals. Most will likely stay near the middle of the ranges.
The toughest call is for eastern Connecticut and southeastern CT. For SE CT, we are concerned about the extent of the rain/snow line and dry slotting. I think there will be mixing and rain there, but how long and how deep into the state that line goes is heavily dependent on the track of the low.
Snowfall Accumulation
As you saw above, we’re upping the numbers slightly. For me, this is less guidance driven and based more on higher confidence of higher totals in western Connecticut. For the central portion of the state, I think our original 6-12 call works. Everyone should keep in mind that not everyone is going to get the upper end of these forecast totals. Most will likely stay near the middle of the ranges.
The toughest call is for eastern Connecticut and southeastern CT. For SE CT, we are concerned about the extent of the rain/snow line and dry slotting. I think there will be mixing and rain there, but how long and how deep into the state that line goes is heavily dependent on the track of the low.
The GFS model has been the least bullish, and you can see why. It brings the low very close to the coast, bring a period of rain to many. I’m not entirely buying, and certainly not buying the temperature profiles it has been spitting out. However, it illustrates the risk.
Snowfall Rate
As I said above, the dynamics of this storm are strong. I expect a period of very heavy snow that will cause difficult travel conditions during the afternoon and evening hours tomorrow. Looking at some of the soundings (upper air profiles) we see great snow growth and some hints of instability, which could be a signal for some thundersnow. Though we’re not necessarily calling for that, anytime it’s worth a mention you have a dynamic system. Snow will not start out heavy…expect some lighter snows early that becomes heavy over time. In addition, some of the guidance shows dry slotting possible. Whenever you are close to strong bands, you see dry slots possible on either side of a storm. That’s another potential bust factor. Snow lovers should be keeping an eye to the radar tomorrow as some guidance has a signal for dry slotting and lighter snows in eastern CT.
Snowfall Rate
As I said above, the dynamics of this storm are strong. I expect a period of very heavy snow that will cause difficult travel conditions during the afternoon and evening hours tomorrow. Looking at some of the soundings (upper air profiles) we see great snow growth and some hints of instability, which could be a signal for some thundersnow. Though we’re not necessarily calling for that, anytime it’s worth a mention you have a dynamic system. Snow will not start out heavy…expect some lighter snows early that becomes heavy over time. In addition, some of the guidance shows dry slotting possible. Whenever you are close to strong bands, you see dry slots possible on either side of a storm. That’s another potential bust factor. Snow lovers should be keeping an eye to the radar tomorrow as some guidance has a signal for dry slotting and lighter snows in eastern CT.
High resolution NAM showing very strong banding potential tomorrow and the risk of dry slots. Don't take any of these model runs as gospel. They are all merely a tool to help us better understand the evolution of the storm.
Wind/Power Outages
I know some of you are still without power and are worried about wind potential. Although we will see heavy wet snow for a time in a lot of places, the winds, while strong, do not look as strong as our last system. Therefore, I have expected only a moderate impact in this area, meaning scattered outages around the state. For those that live in power outage prone areas, be prepared.
Timing/Road Conditions
Timing seems relatively straight forward. Snow showers may begin during the overnight hours, and snow could be slow to arrive tomorrow morning. Light snow should be falling in SW areas by daybreak, with the NE corner in the precipitation by midday. The worst of the storm is during the afternoon and evening hours, with things beginning to relax a bit by late tomorrow evening. Snow may continue into early Thursday morning.
We always have difficulty forecasting snow timing, so stay tuned to real time updates and the radar to see if things start earlier or end earlier than expected.
I know some of you are still without power and are worried about wind potential. Although we will see heavy wet snow for a time in a lot of places, the winds, while strong, do not look as strong as our last system. Therefore, I have expected only a moderate impact in this area, meaning scattered outages around the state. For those that live in power outage prone areas, be prepared.
Timing/Road Conditions
Timing seems relatively straight forward. Snow showers may begin during the overnight hours, and snow could be slow to arrive tomorrow morning. Light snow should be falling in SW areas by daybreak, with the NE corner in the precipitation by midday. The worst of the storm is during the afternoon and evening hours, with things beginning to relax a bit by late tomorrow evening. Snow may continue into early Thursday morning.
We always have difficulty forecasting snow timing, so stay tuned to real time updates and the radar to see if things start earlier or end earlier than expected.
With regard to road conditions, don’t drive tomorrow if you can help it. Road crews will need to have clear roads for this one, especially in central and western Connecticut. Once we start to see heavier snow, travel will deteriorate fast. I expect widespread cancellations tomorrow, including schools, flights, trains, and local activities. Thursday delays are likely as well especially if snow is slow to shut off.
Overall, although not a historic event, this is a major storm for most due to snowfall accumulations and timing. Winter storm warnings are up for virtually the entire state for a dynamic system that’ll impact us tomorrow and early Thursday. We will have updates during the evening and throughout the storm to keep you informed.
Overall, although not a historic event, this is a major storm for most due to snowfall accumulations and timing. Winter storm warnings are up for virtually the entire state for a dynamic system that’ll impact us tomorrow and early Thursday. We will have updates during the evening and throughout the storm to keep you informed.
For posterity, the 12z European model precipitation plot. Image courtesy of weather.us. The precip will be available. Will the temps cooperate for snow lovers?
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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
