Month: January 2018

The snowstorm that will impact our region has formed and is already over performing in parts of the south. Based on current radar returns, the storm is staying close to the western edge of modeling. However, the models continue to shift back and forth by 25-50 miles, the latest NAM run shifted East a bit, while the RGEM shifted West.

What this means for all of us is that we’re all going to see moderate amounts of snow with some locations on Long Island potentially seeing over a foot. Snow will begin to overspread the area by about 4am, with the heaviest snow beginning around sunrise and continuing until the early afternoon. As I mentioned earlier, the snow may fall at 1-2″ inches per hour, with winds gusting over 30mph. It is likely many will see blizzard and whiteout conditions during the day tomorrow. The snow should end from West to East by mid-to-late afternoon tomorrow. I have outlined my final thoughts on total accumulations below. It is likely that we all will exceed the minimum forecast, and I would not be surprised if some exceed the maximum forecasted amounts.

After the storm exits the region, the coldest air of the season will come into our area, highs on Friday may not get get out of the low teens. The cold will remain through the weekend, but by early next week daytime highs should finally hit the 30’s

Final snowfall forecast:

Here are some radar and satellite shots of our developing storm:

We’re finally starting to see something nearing consensus for tomorrow’s storm. Below find my second call for tomorrow’s storm, and I plan on posting one more later tonight once the 0Z models start rolling in. I do want to mention that for these totals it is possible that we will exceed the maximums, in Nassau and Suffolk depending on the track, and the city may end up below the minimum. (Yes I know typical weather person hedging their bets)

Snow is expected to begin between 2am and 5am Thursday morning. It will pick up in intensity during the morning, and continue until late afternoon. During the storm, snowfall rates may exceed 1-2″ per hour with winds gusting over 30 or 40mph, leading to blizzard conditions and drifting snow. While this storm will not feature the heaviest snowfall we have seen in the last few years, it will be very intense between the winds and the snowfall rates. Currently Suffolk County is under a Blizzard Warning and Nassau and the City are under Winter Storm Warnings. I expect  the Blizzard Warnings to be extended to Nassau County if recent trends hold. More to come later.

I’ve been asked by many for an update so here it is:

The reality is at this point, there is still significant disagreement amongst the models and I can’t say with certainty how much to expect. As I said yesterday, the low is just forming and all the players are finally coming together. The dynamics involved are highly complex, and slight differences in model interpretations are leading to huge differences on the outcomes. The NAM currently is showing an area wide snowfall of 8″+ (This includes NYC), the GFS is right around my first call last night with only a slight bump up on Long Island, the CMC is lost, the RGEM is going back and forth between the NAM totals and the GFS. Needless to say it’s very hard to give a definitive snowfall amount as of now. The confusion is so great that the NWS is actually sending up Hurricane Hunter planes this afternoon to get readings over the ocean due to all this uncertainty. This all is very similar to our surprise big snow storm two years ago, when we went from a 2-4″ storm to over a foot with only 8-12 hours notice. For now, I’m sticking with my first call from last night, but it’s subject to significant change. I’ll keep you posted.

Model disagreement continues this evening, with the models waffling back and forth by 50-100 miles. Which as I mentioned this afternoon can mean a significant difference in total snowfall. My forecast below is a first call and will very likely change by tomorrow evening. At this point, I’m thinking that we’ll be impacted by a moderate snowfall region wide, with more snow the further east you go. The snow will begin before sunrise Thursday and continue through most of the day. Due to the strength of the storm, it likely will be fairly windy as well, and of course cold.

First Call Map:

SIM Radars from RGEM and NAM:

I hate to be the bearer of bad news on this first day of 2018 (ok maybe I enjoy it a bit), but we are potentially in the path of a large storm for Thursday morning/day/night. As of this afternoon, the weather models are in two camps with the Global models portraying a light to moderate event for our region. While the Hi-Resolution “Meso” models, are beginning to hint at a far more significant event. We are currently at the long range end of the Hi-Res models, but in the past they have picked up on some of our bigger events that the global models were not enthused with. I am not yet ready to commit one way or the other at this point in time. There are still a few major wild cards, with the biggest being some energy that is dropping down from the North Pole region that will not be sampled at all for at least another day. The strength and positioning of this energy will make the difference between a small event and a major snowstorm. I’ll continue to provide updates over the next few days.

As a side note, the cold we are experiencing likely will not end until after the weekend. Keep warm everyone.

Here are a few sim radars from the Hi-Res modeling. Note that these models are typically most accurate within 48 hours of an event, but as I said above they often can identify important features that the global models may be missing.