January 2nd, 2025

 

Daily forecast discussion…

Well, we made it to 2025. I hope all y’all had a safe and wonderful New Years Eve and Day. I’m very thankful for those of y’all who are following my Wx4Cast blog post. I want to start up a YouTube channel about Northeast weather. While this will increase my workload, I do think it will make for a better experience for all y’all. But that is going to depend on having a lot more eyes and views on a daily basis. I want to go into the YouTube venture knowing it will be successful. So, I will need your help to make that happen.

This post will be rather long, as it will cover the weather over the next few days, as well as go into a lot of detail on the weather pattern for January into February.

For today into the Weekend…

Here is a look at the current surface chart and radar. We can see a trough moving over the region, with lingering snow showers over parts of the region, as the system departs. We have an upper-level low (circled on the satellite chart) over southeast Canada, this is drawing in the cold breezy air, leading to the lake effect snow is falling downwind of Lake Erie and Lake Ontario. Winds will be windy/breezy today. The bands should stay generally where they currently are southeast of Lake Ontario, and over places like the Boston Hills off of Lake Erie, along with chances for thundersnow. Then tonight they will shift north closer to Buffalo and onto the southern Tug Hill. They will stay here for most of Friday, before drifting back south for Friday night into Saturday. On Saturday the Erie Band should be weakening, but the Lake Ontario band will keep going into Sunday before weaking and dissipating. Off of Lake Erie those under the most persistent bands will see 1-2+ feet of snow, while the persistent bands off of Lake Ontario will see 2-3+ feet over the course of the next few days, under the heavy band, thundersnow can be expected.  With the winds, there will be blowing and drifting snow causing reduced visibility and difficult travel conditions within these bands. Then for Friday, away from the Great Lakes winds will lessen.  Over the Weekend, the upper-level low over Southeast Canada, will retrograde (move west) toward the Hudson Bay. This will become a player in the setup for Sunday and Monday.

 

On Friday a weak disturbance (red circle on satellite) will be dropping out of the Midwest, this is going to slide east-southeast heading for the Mid Atlantic Coast, this could bring some light snow showers to parts of southern Pennsylvania, Maryland, Delaware into the Delmarva. This will move offshore, and become a player in what happens for Monday into Tuesday.  Once offshore this is going to deepen and head toward Atlantic Canada. Winds will become an issue again on Saturday.

We will have a system that will be coming ashore on the West Coast tomorrow, then we will see low pressure develop over the Rockies.  This storm will then be coming east continuing to develop as it does so.  That strong area of low pressure up near the Canadian Maritimes, will force this system south. Another big factor will be warm air streaming in from the south and cold air dropping out of the north, as this will play a role in the storm track. The storm will be entering the Tennessee and Ohio Valleys by Sunday. Then for Monday into Tuesday this will be sliding east then head out to sea. This has the potential to bring an ice storm for areas south of our region. But there are some signs that this could trend north a bit, which would bring Maryland and Delaware into southern New Jersey in line for sleet and ice. If the storms stay south, it has a chance to bring the first accumulating snow of the season is likely for the Middle Atlantic region as well as the Delmarva Peninsula.  Snow could be heavy at times. Some of this could push into Southern Pennsylvania, especially the Allegheny Mountains and the Laurel Highlands. But again, if the storm trends north the heavier snow could be across Pennsylvania and northern and central New Jersey, New York City and Long Island could also cash in on heavier snow amounts. Which one of these scenarios occurs, will depend on the atmospheric dynamics and wind flow (confluence) caused by that strong storm in Newfoundland and Labrador and low pressure near the Hudson Bay.  

 

 

Looking ahead…

 

The cold air outbreak I’ve been talking about for what seems like forever, is upon us. So here is a little bit that explains why this is occurring.

The cold will be coming in three main waves. The first wave of cold is coming in now behind the New Years disturbance. A second shot will come in over the weekend with that southern system. Then a third much more substantial shot of arctic air will come in next week. The third wave will be accompanied by a piece of the polar vortex that will be dropping into North America.

This won’t be a short deration cold snap, instead it will last for two maybe three weeks, where interior parts of the Northeast will likely experience subzero temperatures for many days.  We can expect temperature departures of 30°F to perhaps 50°F degrees below average, with some areas in northern parts of the region experiencing general anomaly departures greater than that.

This is going to be a deep trough that pushes the cold air into the interior Southeast and likely into Texas, the Gulf Coast into Florida, first to second weeks of January.

Pacific equatorial sea surface temperatures (SSTs) anomalies are below average, between the Dateline and the South America coast, indicating that a weak La Nina event is trying to get its act together. But if these does indeed happen, it might be too late to have a big impact for January into February. So much of the rest of winter could be under the influence of the Madden-Julian Oscillation (MJO), Arctic Oscillation (AO) and North Atlantic Oscillation (NAO).

 

 

As I’ve said many times, the PV is just an area of low-pressure over the arctic with wind that loops around the North Pole in the upper Atmosphere. Currently the AO is near neutral. Then looking at the chart, we can see the AO will become extremely negative, when the AO is negative, the PV is considered weak and it can become stretched or have pieces break off and move south.

The NAO currently is neutral to weak negative. From here it’s going to become  strongly negative for a large part of January. When the NAO is in positive phases the eastern U.S tends to see above-normal temperatures, with the opposite being the case when the NAO is negative. We tend to see more high latitude blocking events when the NAO is in its negative phases.

The MJO currently is in phase seven. Then the MJO is looking to be at least mid-amplitude for a bit while in phases 8 and 1. When this happens, we will see ridging in the Western US and a trough develop in the East, allowing colder air to our north coming down to visit.

The Pacific North American (PNA) index. Looking at the chart, we can see this is going to be positive. This reinforces the NAO and AO ideas of increased cold here in the Eastern CONUS.  When the PNA is positive it greatly increases the NAO’s influence on temperatures here in the Northeast. A 2006 paper done by M. Notaro, W.C. Wang AND W. Gong showed that a positive PNA enhances the chances of troughing over the East Coast, with the Jet Stream suppressed south. The paper also showed a positive PNA increases the chance for lake effect events.

All of these teleconnections are showing a strong signal for a very cold pattern that favors snow storms.

I expect to see at least one big nor'easter during this time period.  

Places that have significant snow cover will help the Arctic air to spread farther southward spread, bring very cold air into the southern states. The pattern over the next couple of weeks will be less favorable for the cutters and inland runners that we have been seeing. So, if you want to see a coastal this is the pattern for you.

The teleconnections are showing the pattern breaking down once we get past mid-month. Based on the data, this would likely come about after the 19^th of January.

I'm still expecting the pattern to warm end of January, before the return of another cold shot during the first part of February, as this back and forth pattern looks to continue. 

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