Feb 18, 2011: Winter Returns Again

With a storm located well to the north of the area in southern Canada, partly to mostly cloudy skies, a warm air mass and a southwest wind, the area got an early taste of spring today, peaking in the upper 50s to mid 60s across the area, with Newark even reaching the 70 degree mark, breaking their previous record high of 69 degrees for this day. This warmth is now coming to an end, however, as a cold front which previously resulted in a thunderstorm in parts of the area earlier this evening will bring much colder temperatures along with it, reminding us that winter is not over just yet.

Tomorrow will be a much colder day, but the wind will be the main issue, expected to gust between 50 and 60 mph across the area, and earlier this evening I issued a High Wind Watch for the area, which may be upgraded to a warning on Saturday morning. The wind will calm down by Sunday, however cloud cover will increase ahead of the next two storms, one on Monday morning and the other on Tuesday morning, and while these storms will likely bring the best chance of moderate to heavy snow north and south of NYC, some snow is still expected to fall in the area.

Tomorrow’s Outlook: Very Windy

Tomorrow will bring much colder temperatures than those of today, expected to be steady in the lower to mid 30s inland and in the mid to upper 30s for the rest of the area, with some lower 40s possible for the immediate NYC area and further south/west.

The main story tomorrow, however, will be the wind. Windy conditions will begin developing tonight, with widespread windy conditions expected to affect the region throughout the day tomorrow. The windiest conditions appear to focus on Pennsylvania, however there will still be very windy conditions in the area, with a sustained WNW wind generally between 20 and 30 mph. Wind gusts will range from 45 mph to as much as 60 mph.

Sunday: Wind Calms Down

The wind will start to calm down tomorrow night, with gusts as high as 30 to 40 mph, however these gusts combined with the cold temperatures, in the 10s away from NYC, will lead to wind chills in the single digits across the area on Sunday morning, with wind chills potentially below zero for the interior parts of the area.

During the day, high temperatures will be warmer than those of Saturday, peaking in the mid 30s to lower 40s across the area, however cloud cover will increase overnight as two storms approach the area from the west.

Monday And Tuesday: Snow Returns Into The Forecast

The area has not seen widespread snow falling since the February 1-2 ice storm. This is about to change, however, as the two upcoming storms will be cold enough to produce snow. There is still some slight uncertainty with the first storm and more uncertainty with the second wave of low pressure, but it does appear that the area will be spared from any big snow, with a rather complicated set up resulting in either the first storm too far north with the snow and the second storm too far south, or one of these storms bringing moderate snow, or both of them doing so. The question is how much snow falls.

Sunday Night – Monday Storm: The first storm will affect the area starting on Sunday night. A low pressure near Chicago on Sunday night will race eastward, reaching Cape Cod by Monday afternoon. There is still some slight uncertainty with the exact track, which could be slightly north or south of the track mentioned above, however this slight difference will have a large impact when it comes to the forecast.

The first scenario, currently supported by the models and the more likely scenario at this time, is the one I went with for tonight’s forecast for now. Light snow will spread from west to east across the area between 10 PM and 4 AM, and as 850 mb and surface temperatures begin to warm up, the area starts to mix with and change over to rain/sleet from southwest to northeast. The best chance of light to moderate snow accumulation is for the interior northern parts of the area, where I may issue a Light Snow Alert with tomorrow’s update.

The second scenario is one that does not have much support, but needs to be watched as it may result in a snowstorm for most of the area. This solution was also supported by the 00z NAM, where the storm tracks south enough to bring moderate snow for most of the area on Monday morning, changing over briefly to light rain before ending in the early afternoon. This solution would support a widespread moderate 3 to 6 snowfall from NYC and further west/north/east, in which case I may need to issue a Snow Watch. This solution only recently began showing up on the models and does not have much support, however it will be watched in case it becomes a new trend. Stay tuned for more information on this potential change in the forecast.

With both scenarios, the storm would end on Monday in the early afternoon, but what happens afterwards during the afternoon and evening hours again depends on the track. With the further north track, as the area is briefly in the warm sector of the storm, temperatures would briefly surge in the late afternoon well into the 40s for parts of the area and the lower-mid 50s for the immediate NYC area before dropping again in the evening. With the colder solution, temperatures would not rise as much, staying in the upper 30s to mid 40s across the area.

Monday Night – Tuesday Storm: The second storm is the more uncertain one, but the one with more potential to bring a widespread moderate to heavy snowfall to parts of the region. As a very cold air mass in Canada pushes south behind the first storm, the second storm will be more suppressed, in fact the greatest threat of snow at this time is to the south and southwest of the area, meaning that if any precipitation falls in the area from this storm, it will be snow. The question is how much the storm is suppressed, which brings the range of possibilities from either some flurries to a 5-10 inch snowfall.

The second wave will begin developing in the Ohio Valley on Monday evening, moving east by Tuesday morning, though where it ends up and how strong it ends up is still uncertain. At this time, most of the models take this through southern Virginia, bringing a moderate to heavy snowfall for the central Mid Atlantic, focusing on Maryland and southern Pennsylvania into southern New Jersey, with some snow showers for the area. Some models, however, have been taking this further north, including the 00z NAM, bringing a moderate snowstorm to the area. At this time, I am favoring a solution in between the northern and southern scenarios, bringing some light snow to the area, however it is possible that the storm may trend north to bring a moderate snowstorm to the area. Stay tuned for more information on this storm and how it may affect the area.

Longer Range: Cold And Windy Again

Behind the second storm, strong cold air will push into the region, with windy conditions expected to return once again. High temperatures will be very cold compared to the average for this time of the year, expected to be in the mid 20s to lower 30s across the area for Wednesday, with low temperatures in the 10s. Temperatures will warm back up towards the average by Thursday, however, and the next storm potential returns by February 26.

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