Posted below is the first summary of expected conditions from a Nor’ Easter moving through on Saturday. The detailed Premium forecast, published earlier, is available for purchase here and contains analysis both for this storm and the storm on Monday, as well as additional long-range pattern analysis. Similarly, should you want consistent email updates whenever the forecast is updated alongside more detailed updates on all future storms, you may subscribe for our Premium service here. Otherwise, we will dive into the first overall outlook of the Saturday storm, with relevant portions of the Premium forecast freely attached below:
The consensus is away from a large snow storm for the area. However, there is still wintry precipitation coming during the day on Saturday, and it will bring travel troubles. Precipitation type is the number one variable with this storm. If the storm trends colder and we end up seeing all snow, totals could get up to 5 or 6 inches. The snow would be very heavy and wet, so accumulations would generally be 8:1 to 10:1 or so. If there are warmer trends aloft but colder at the surface, we could see a fairly sizable ice storm in areas with a tenth to two tenths of an inch of ice coating roads. This is more likely across inland areas. And if the temperatures aloft and the surface are warmer, we could end up just seeing plain rain in the middle of the day. Again, with the ice threat, a couple of degrees difference could determine whether roads are extremely slick or almost completely normal, so there will be a lot of work from here on what exactly happens.
Now, I want to outline what I see happening from this storm. First, I see snow starting around 3 or 4 AM Saturday morning. It’ll be a light snow at first, accumulating about an inch through 6 or 7 AM. Between 6 and 8 AM, I believe the coast starts mixing in with rain/freezing rain. It should start as freezing rain, but I think by 9 or 10 AM the coast is seeing a combination of freezing rain and rain (where some rain freezes but runs off) or just all plain rain. Temperatures will be in the low 30s, so roads could still be icy in spots and travel a little slick, but by 12 PM I think the coast briefly gets above freezing. There is no cold high to the north to create a real pressure gradient, so this results in winds not being as strong and not as much cold air being pulled in on the back side. By 12 PM, however, I see precipitation turning back over to snow, with maybe another couple inches of snow falling across the entire region. Inland areas are much more likely to stay at least partially freezing rain through the storm, and so there travel could be more significantly impacted.
In terms of accumulations, I’m looking at generally 2-4 inches of snow across the area, with isolated amounts to 5 inches possible in inland New Haven county. There is still a chance that this busts too high in some of the much warmer scenarios where some areas could only see a 1-2 inch range. However, given the fact that we are seeing some snow on the front end and the back end, along with the fact that the storm is rapidly deepening to the point where models could be underestimating some of the dynamics, I think widespread snow amounts of at least 2 inches are likely. I don’t see more than 4 or maybe 5 inches, however, unless we see a significant colder trend with the storm and we see additional moisture looking to move over the region. I just don’t see enough moisture or cold air to support more than 4 inches of snow widespread. The bigger threat is certainly the ice. The National Weather Service is currently calling for a tenth of an inch of ice, and this is in line with what I am expecting as well. I could see some areas getting up to two tenths of an inch of ice inland in worst case scenarios, but I’m not ready to forecast that yet. General ice accumulations from .05-.15 inches across the region look most likely. To put this in perspective, ice accumulation with the terrible travel last Sunday morning was around or less than .05 inches in most areas, so you can see how ice really can mess with roads. However, surface temperatures will not be as cold in the upcoming storm as they were then, so properly treated roads should not be quite as bad. Similarly, the word of this storm is getting out sooner, so that should allow crews time to prepare the roads as well. The worst freezing rain would likely occur between 7 AM and 11 AM on Saturday.
The final forecast will be freely released around the same time tomorrow night. Premium members will continue to see more regular updates prior to the storm with various model changes and will receive tweaks to the forecast in email updates through the day on Saturday. Either way, be sure to stay tuned for the latest as this potentially travel-snarling storm nears.