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John Homenuk

After transient warmup, winter set to return

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This is not the news many were hoping to hear this morning. Unfortunately, it’s the news we have to provide as a result of medium and long term forecast modeling and the overall hemispheric evolution over the next two weeks. Luckily for those who enjoy the warmth, today looks to be the winner of the week. Behind a mid level atmospheric disturbance which provided the area with rain on Tuesday, warm mid level temperatures will remain in the area on Wednesday. Periods of sunshine and west winds will allow temperatures to rise into the mid to upper 50’s throughout the area. Some areas will approach and may even exceed 60 degrees during the afternoon. Others, especially near the shore, will remain slightly cooler.

The warmth, as is often the case this time of year, won’t last long. Colder mid and upper level temperatures will push southward on Thursday and Friday and temperatures will move back toward more normal levels. The transient pattern will continue through the weekend as another disturbance approaches — bringing precipitation mainly in the form of rain, as temperatures briefly warm up once again before crashing back down on Sunday. Still, that will be just the beginning of the trend toward a colder, more active pattern which will establish itself in the medium to long range.

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John Homenuk

On this winter, records, and cold

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I enjoy data. New York City’s weather station has been keeping data records for 152 years. Yes, that’s right, observers have been collecting weather data in New York City since 1863. That, my friends, is a long time ago. Since then, there have been an innumerable amount of impressive weather events. Hurricanes, winter storms, severe weather, flooding, heat, cold. New York City’s geographic location features an incredible amount of variability and extreme differences based on location. These simple facts, as straightforward as they are, make this winter — especially from February through early March — all the more impressive.

When looking at this winter as a retrospective, although it isn’t yet over, one can easily become caught up in statistics and information. This February through March in New York City will go down in the record books as one of the more impressive and extreme winter weather periods. For both cold and snow, the past 60 days have been historic.

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John Homenuk

Live Blog: Morning, afternoon model guidance and analysis

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4:00pm: The National Weather Service has issued Winter Storm Warnings for most of New Jersey including the New York City Metro Area from late tonight into Thursday. Generally, their forecast calls for 3 to 6 inches of snow with higher amounts of 5 to 9 inches possible south of New York City throughout parts of Central New Jersey. Lighter amounts of 2 to 5 inches are expected farther north in New Jersey, where a Winter Weather Advisory is in effect. You can read the warning text here. 

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2:35pm: We are now beginning to get into range of the HRRR Model (High-Resolution Rapid Refresh). It updates every hour and only runs out to 15 hours in time. It can sometimes be good at pinpointing short-term trends in banding and changeovers from rain to snow. The latest HRRR model has rain changing to sleet at around midnight, then to snow at around 2:00am, and it comes down very heavily.

HRRR Model showing the changeover from rain to snow overnight (Courtesy of Weatherbell Analytics).

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John Homenuk

Substantial snowfall possible Thursday

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On the heels of a strong southwest flow event which left the area under more snow and sleet this Tuesday into Wednesday morning, a low pressure system is forecast to develop late Wednesday into Thursday and deliver another round of snow. This time, it looks more significant in terms of snowfall accumulations. As a cold front sinks south of the area Wednesday, mid level energy will shift from the Central United States eastward, forcing the development of a low pressure system from the Southeast States into the Mid Atlantic.

A thermal gradient, or baroclinic zone, will be positioned from the Ohio Valley through the Mid Atlantic and Northeast, serving as a highway for the development of precipitation. As the mid level jet dynamics are enhanced Thursday, snow will become more widespread throughout the Mid Atlantic and Northeast United States. On the northern periphery of the forcing for moderate to heavy precipitation, a band of moderate to heavy snow is likely to develop.

Programming Note: We will have a Storm Total Snowfall forecast for release around 11:00pm tonight.

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