Jan 11: Late weekend storm, long range warmth?

Tonight: Mostly Cloudy. A few snow showers possible. Low temperatures will be in the upper 10s to lower 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast.

Tomorrow: Mostly Cloudy. A few snow showers possible before noon. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the mid to upper 10s north and west of NYC, and in the lower to mid 20s for NYC and closer to the coast.

Wednesday: Partly Cloudy. High temperatures will be in the lower to mid 30s across the region.

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Late Week Warm-Up Scenario:

A relatively quick warm up will be in store for the region late this week. After Wednesday, which as the forecast above shows will still have highs in the low to mid 30s, a warm up from our west will be affecting our region on Thursday and Friday. High temperatures on both days will be above average, peaking in the upper 30s to lower 40s north and west of NYC and in the lower to mid 40s for NYC and closer to the coast. By Saturday, we should get a small cool down with highs returning into the 30s.

Late Weekend Storm:

For the storm late next weekend, there is a lot of uncertainty on what solution happens with the storm. What we do know at this time is that there is a storm forming in the Gulf of Mexico (represented by the L (low pressure) in the map below), and there is a relatively weak cold air mass with a high pressure in the north:

However, what happens afterwards is where the uncertainty begins. At first, the GFS ensembles were consistent on a coastal low solution with snow along and north of Interstate 95. Several other models were showing a solution where the storm starts going towards the Appalachians (called an Apps runner), however then transfers its energy to a developing coastal low, that brings a wider area of snow and ice. The high pressure in southern Canada stays in place, keeping at least some of the cold in place.

However, the models today ended that consistency. On the GFS model, which last night showed a big snow/ice storm for the northern Mid-Atlantic, the storm is now not even able to make it further north than North Carolina, bringing rain to the parts of the Southeast it impacts except for the mountains of western North Carolina. There have been several other models showing this solution, including the DGEX. However, there are also models still showing the Apps runner to coastal scenario, including the GGEM.

Which solution is going to be the most likely out of these two is the most difficult part to answer. The high pressure in southern Canada will prevent this from going all the way up the Apps and producing rain for the area, meaning that if it does try to take that route, it will have to transfer energy to a coastal low, which would bring snow, ice and rain to the area. This is shown in Scenario A below.

However, if it does not try to go up the Apps and continues moving through the Southeast, we will have two possible solutions, one of them being the out to sea solution, shown in Scenario B. In this scenario, however, there would not be a lot of cold air with this storm, and other than the mountains in westen North Carolina which would see snow/ice, the rest of the Southeast sees mainly rain.

The other scenario, which I did not show, is where the storm goes near the benchmark (40N/70W), which is a location favorable for snow along Interstate 95, and produces snow along that region. I am not in favor of this solution at this time, but we cannot rule anything out yet due to the uncertainty.

Below are my two scenario maps for this storm at this time, and they are subject to change. Also keep in mind that there are several other possible solutions, however I decided to focus on these two solution as I think that they have the highest probability of happening at this time.

Long Range Update, Warmth Possible?

On January, we typically see at least one period of mild weather, called the January thaw. In last year’s January, that was only temperatures briefly in the 40s before returning into the 20s. However, going back to January 2007, record warmth affected the area as highs warmed into the 70s, making it feel like June instead of January. Some trees and plants even started to briefly grow again.

Luckily, this time, we should not be seeing anything extreme, but still something warmer than what we are seeing now. The long range GFS model is showing significant warming in our area after January 20th, with temperatures as much as 10 degrees above average, meaning high temperatures in the 40-50s. And if we were to go by that model, this would not be brief, but a sustained warm up across all of the United States and even parts of Canada.

While this is too far in the long range to be certain, the pattern is also supportive of a warm up happening, so for now, it’s most likely safe to say that we will be seeing above average temperatures after January 20th. However, how much above average temperatures will be, how long this lasts and when we get a return of the cold and snow is still a question.

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