Today's GFS model valid for Saturday afternoon shows 850mb temperatures warming up to +6C.

Friday Chill Gives Way to a Warm Weekend

The chilly high pressure system to the north will have one more day of influence before it finally gives way to a very mild weekend. The high pressure is currently sliding out to sea, which will shift our winds to the east and south, but with ocean temperatures so cold this time of year, it can still lead to chilly temperatures. As this high pressure slides further east and away from us, a warm front will approaching the area from the west. This combination will lead to high and thin clouds increasing as the day goes on. Generally, high temperatures will be around 40 degrees.

The warm front will be moving through the area tonight. A weak area of moisture out ahead of it may be able to trigger a few rain and snow showers during the overnight, but we are not expecting any accumulations — a slight chance for a slushy coating in some cold surfaces north of the city. Temperatures will generally hold in the 30s tonight as a much milder mid-level airmass moves in once the warm front swings through.

Once the warm front moves through, winds will shift to the southwest, which has a warm source region and is not ocean-contaminated. When this is combined with afternoon sunshine (after some morning clouds) and a warm mid-level airmass, widespread temperatures in the 50s become likely! It will feel quite warm in the sun, so even a few outdoor activities may be had. Some parts of Long Island, though, will hold in the 40s due to southwest winds still having some onshore/Atlantic component.

Today's GFS valid for Saturday afternoon shows southwest winds allowing us to surge into the 50s.

Today’s GFS valid for Saturday afternoon shows southwest winds allowing us to surge into the 50s.

A weak cold front will move in on Saturday night, but no moisture with it is expected. While the airmass will cool slightly, the cold front will just lead to more mixing and downsloping with westerly winds. Thus, temperatures should still hold in the upper 30s to low 40s for most spots. Sunday will also have the downsloping to “make up” for the slightly cooler airmass, so temperatures should reach the low 50s again — perhaps even on all of Long Island as well.

Attention then turns to a wave of low pressure on Sunday night (from ~10:00pm Sunday night through ~5:00am Monday morning). Given the warm airmass, it should most likely just be some rain showers mixed with snow showers. However, with cold air to tap into in Canada — a stronger wave of low pressure that times itself when it’s inherently cooler at night could lead to some accumulating snow as well. The NAM model shows a strong shortwave that leads to heavy precipitation, which cools the column enough for several inches of snow to fall. Right now, the accumulating snow scenario looks unlikely, as the flow looks too compressed aloft for a strong shortwave to truly develop, and thus the precipitation would either miss us to the south, or be too light to cool us off enough for snow. We will still be keeping an eye on it, however.

Skies clear again on Monday and temperatures still look relatively mild, while we await the mid-week storm. Right now, it is looking a bit mild and rainy, but mixed with snow solutions are still possible — almost anything is still on the table.

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