Good evening to you from Southern Connecticut Weather!
As Greg discussed last night, we’ve got dangerously cold temperatures on the way for tomorrow and Friday, followed by accumulating snow on Saturday for the entire state. This discussion will take a first look at that storm system and give you some early thoughts on accumulations. We’ll also take a look at the cold and wind expected for tomorrow into Friday and see just how cold it’s going to get!
Part 1: The Arctic Blast
A strong arctic shot is currently tracking eastward towards us. You can see on the current temperatures map that the core of the cold is currently located over the upper Midwest and Plains, where daytime highs are below zero today! That cold will translate east into our area over the next ~24 hours, leading to a frontal passage tomorrow morning and much colder temperatures in our area by tomorrow afternoon. Here’s a look at the progression of temps throughout the day tomorrow on the hires NAM.
As Greg discussed last night, we’ve got dangerously cold temperatures on the way for tomorrow and Friday, followed by accumulating snow on Saturday for the entire state. This discussion will take a first look at that storm system and give you some early thoughts on accumulations. We’ll also take a look at the cold and wind expected for tomorrow into Friday and see just how cold it’s going to get!
Part 1: The Arctic Blast
A strong arctic shot is currently tracking eastward towards us. You can see on the current temperatures map that the core of the cold is currently located over the upper Midwest and Plains, where daytime highs are below zero today! That cold will translate east into our area over the next ~24 hours, leading to a frontal passage tomorrow morning and much colder temperatures in our area by tomorrow afternoon. Here’s a look at the progression of temps throughout the day tomorrow on the hires NAM.
As you can see, it’s going to be chilly tomorrow morning and it’ll only get colder, as temperatures will steadily drop throughout the day. The core of the cold moves in Thursday night, and Friday morning’s lows will be as low as thirty degrees below normal! Here’s what that looks like, again from the hires NAM.
We’ll see some rebounding on Friday, but highs will only make it into the upper teens to lower 20s; that’s around 10 degrees colder than the average low for this time of year! To make matters even colder, we’re going to see some very strong winds tomorrow and Friday as a strong high pressure is overhead. I expect sustained winds in the 25 to 40 MPH range, with wind gusts as high as 60 MPH! As such, a High Wind Watch is in effect for the entire state. The combination of winds and cold will lead to daytime wind chills on Thursday and Friday in the single digits, with wind chills Friday morning in the negative double digits across most of the state. This is dangerously cold weather and can be life threatening in as little as thirty minutes if not properly protected – make sure you are bundled up and exposed skin is limited when going outside! Also, please check on your family and neighbors to make sure that they all have heat, and remember to bring outdoor pets inside. Additionally, with the winds, we will likely see some scattered power outages due to weakened trees and power lines – have warm clothing accessible and have a backup plan for warmth, either a generator or another location you can plan to go to. Now is also a good time to check that you have fresh batteries in your carbon monoxide detectors!
We could also see some snow squalls tomorrow and Friday off the great lakes – best chance for those will be in the northern and western portions of the state. Any snow that falls will be very high ratio due to the cold temps, and so a quick light accumulation is possible wherever any squalls develop. Overall, a bitterly cold taste of the arctic is on tap to close out the week. We’ll warm up as we move into the weekend, but before we do, we’ll get to experience another part of winter as a snowstorm approaches for Saturday morning, bringing us to:
Part 2: Saturday Snow
Models and Trends
If you followed our discussions for Monday’s event, this may read like a broken record, as we’re looking at a similar sort of system. A weak area of low pressure will bring overrunning precipitation over our area early Saturday morning (formed when warm air overruns a colder airmass closer to the ground), and will bring accumulating snow to the entire state from early Saturday morning through midday. Models are in excellent agreement on the overall track and timing, and the only differences that remain are relatively minor ones regarding the onset of the precipitation and the arrival of the warmer air. To illustrate, here’s a look at the GFS, GGEM and NAM for 7 AM Saturday and 1 PM Saturday.
We could also see some snow squalls tomorrow and Friday off the great lakes – best chance for those will be in the northern and western portions of the state. Any snow that falls will be very high ratio due to the cold temps, and so a quick light accumulation is possible wherever any squalls develop. Overall, a bitterly cold taste of the arctic is on tap to close out the week. We’ll warm up as we move into the weekend, but before we do, we’ll get to experience another part of winter as a snowstorm approaches for Saturday morning, bringing us to:
Part 2: Saturday Snow
Models and Trends
If you followed our discussions for Monday’s event, this may read like a broken record, as we’re looking at a similar sort of system. A weak area of low pressure will bring overrunning precipitation over our area early Saturday morning (formed when warm air overruns a colder airmass closer to the ground), and will bring accumulating snow to the entire state from early Saturday morning through midday. Models are in excellent agreement on the overall track and timing, and the only differences that remain are relatively minor ones regarding the onset of the precipitation and the arrival of the warmer air. To illustrate, here’s a look at the GFS, GGEM and NAM for 7 AM Saturday and 1 PM Saturday.
Overall, all the models have the same idea. They all bring a period of moderate to heavy snow in early Saturday morning, and all (except the GGEM, which we are tossing for this portion of the forecast) warm at least part of the state to above freezing by the early afternoon. The exception may be in the hills, where colder air can hang on longer at the surface despite the warming mid levels and precipitation would change over to sleet and freezing rain instead of plain rain. As of now, the guidance is in good agreement that the rest of the state will warm enough at the surface to change over to plain rain, but considering the strength of the airmass in place, I would not be surprised to see a trend a bit colder for some of the other interior locations over the next few model cycles. Will hold off on any icing for now, but don’t be surprised if we see some accretions work their way into a later forecast for Saturday afternoon.
Over the past couple of model cycles, we’ve seen a trend towards bringing in the initial precipitation faster and disconnecting it from the main storm out to our west somewhat. This serves two purposes. First, it flattens out the trough behind it and means the followup portion of the system on Sunday is not as amplified, and secondly, it brings the precipitation in ahead of the warming midlevels, giving us longer period of time in a snow column before temps rise. If this trend continues, we may have to increase snow amounts somewhat tomorrow or Friday, but I’m not ready to do that just yet. Similarly, if we see a reversal of that trend, we will have to lower amounts, especially along the shoreline.
Behind the system, we will see a quick break in the rain as the first round of precipitation moves out, then temps will spike into the 50s for most on Sunday as the primary low passes to our west. This will bring some more rain, possibly changing to snow on the back end Sunday evening as temps crash back into the 20s and eventually teens by Monday morning, causing a flash freeze of whatever has melted. We’ll take a closer look at that part of the storm tomorrow.
Forecast and Timing
Normally, we would wait until 48 hours before first flakes to issue a snowmap, but considering the model consensus, relatively low bust potential, and the fact that Saturday is the biggest shopping day of the year and there will be a lot of people out and travelling, we decided to issue a preliminary forecast this evening. Here’s a first look at our expected snow totals.
Over the past couple of model cycles, we’ve seen a trend towards bringing in the initial precipitation faster and disconnecting it from the main storm out to our west somewhat. This serves two purposes. First, it flattens out the trough behind it and means the followup portion of the system on Sunday is not as amplified, and secondly, it brings the precipitation in ahead of the warming midlevels, giving us longer period of time in a snow column before temps rise. If this trend continues, we may have to increase snow amounts somewhat tomorrow or Friday, but I’m not ready to do that just yet. Similarly, if we see a reversal of that trend, we will have to lower amounts, especially along the shoreline.
Behind the system, we will see a quick break in the rain as the first round of precipitation moves out, then temps will spike into the 50s for most on Sunday as the primary low passes to our west. This will bring some more rain, possibly changing to snow on the back end Sunday evening as temps crash back into the 20s and eventually teens by Monday morning, causing a flash freeze of whatever has melted. We’ll take a closer look at that part of the storm tomorrow.
Forecast and Timing
Normally, we would wait until 48 hours before first flakes to issue a snowmap, but considering the model consensus, relatively low bust potential, and the fact that Saturday is the biggest shopping day of the year and there will be a lot of people out and travelling, we decided to issue a preliminary forecast this evening. Here’s a first look at our expected snow totals.
Overall, we’re expecting a moderate, advisory level event across most of the state. Precipitation will move in west to east and warm air from south to north, so we will see a classic SE to NW gradient. In the far SE corner of the state, where the snow will be last to arrive and the warm air first to arrive, I expect one to three inches of snow. Elsewhere, I’m expecting two to five inches of snow for the majority of the state, with the warmer temperatures along the shoreline negated by the earlier onset of snow there. And finally, in the NW hills, where cold air will hold on the longest, I’m expecting three to six inches of snow. It is that zone that I am least confident about, as it would only take a small tick colder to bring a warning level snowfall to that area, but I’m not quite ready to go for that yet. We will be watching the models closely, and especially tomorrow will start to see some of the higher resolution shore-term guidance come in, and we’ll make a call tomorrow evening on if totals there will need to be increased.
As far as timing goes, expect snow to break out in the wee hours of Saturday morning, with the whole state seeing snow by daybreak. Snow will change to rain over the course of the morning from south to north, and the whole state save the hills should be raining by the early afternoon. Rain will move out Saturday evening and we’ll see a break overnight before the rain from the primary system comes in for Sunday.
Impacts
Overall, it looks like a moderate snow event for the state that comes on the back end of a bitterly cold arctic airmass. Please ask us any and all questions you have here, on our Facebook, or on Twitter @SouthernCTWX. Also, please consider sharing this discussion with your friends and family to spread awareness about this system. We’ll be back with an update tomorrow evening and a final call will be issued tomorrow evening or during the day on Friday – until then, thank you as always for trusting SCW!
-SA
As far as timing goes, expect snow to break out in the wee hours of Saturday morning, with the whole state seeing snow by daybreak. Snow will change to rain over the course of the morning from south to north, and the whole state save the hills should be raining by the early afternoon. Rain will move out Saturday evening and we’ll see a break overnight before the rain from the primary system comes in for Sunday.
Impacts
- A plowable snowfall for most of the state, with a low chance of warning criteria accumulations in the NW hills.
- Difficult travel conditions Saturday morning.
- Moderate risk of power outages due to a combination of snow and the stress from Thursday-Friday’s wind.
- Flash freeze potential Sunday evening due to melting snow and additional rain.
Overall, it looks like a moderate snow event for the state that comes on the back end of a bitterly cold arctic airmass. Please ask us any and all questions you have here, on our Facebook, or on Twitter @SouthernCTWX. Also, please consider sharing this discussion with your friends and family to spread awareness about this system. We’ll be back with an update tomorrow evening and a final call will be issued tomorrow evening or during the day on Friday – until then, thank you as always for trusting SCW!
-SA
