Dec 31, 2012: Cold Start To New Year

Forecast Highlights:

The active pattern that has been in place over the last week ended in time for the new year, with mostly cloudy skies and isolated flurries expected for the first day of 2013. A cold and dry pattern will continue through the first week of January, with no precipitation expected, which will be followed by a warmer pattern towards the middle of the month.

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This Week: Cold, Dry

As will be discussed in more detail in the updated winter outlook, to be posted later this week, the forecast cold pattern for the start of January will be shorter and much weaker than expected, as the model guidance exaggerated the intensity and southern extent of the cold air mass. Temperatures will still be near to below average this week, but not significantly below average. Other than this change, an inactive week is expected with cold and dry the only highlight of the week. Other than Tuesday, partly sunny skies will persist through the rest of the week, with temperatures peaking in the mid 30s to low 40s on Tuesday and the upper 20s to low 30s for the rest of the week. Overnight lows will generally be in the mid 10s to low 20s except for NYC, in the mid 20s.

Several shortwaves will move through the region this week, but with the pattern remaining unfavorable for any strong storm development close to the coast. A week clipper on Thursday and Friday will produce light snow for the interior Northeast, staying north of the area. Another low pressure looks to develop offshore around Sunday or Monday.


Longer Range: Warmer Again

The pattern will turn warmer again towards the medium range by the 2nd and 3rd weeks of January, as a more zonal flow returns with a strong polar vortex returning into Canada and the loss of the recent ridging in western North America. This time period is not expected to be significantly warmer than average to the extent that early-mid December was, and should still feature occasional cold air masses and snow possibilities for the northern US, but for the NYC area is expected to be unfavorable for any sustained cold and snow chances. More information will be posted on this with the updated winter outlook, as well as the next potential for a more winter-like pattern.