Jan 1, 2016

New Year Ringing in Winter

After a record warm December 2015 across the Upstate of New York, where the warmest ever average monthly temperatures were set in Glens Falls, Poughkeepsie and Albany, we can expect colder weather to head our way.

The arctic blast will move in on Sunday the 3rd day of the New Year. The leading edge of it, the cold front, will be accompanied by some scattered snow showers and squalls. Once the front passes your location expect gusty NW-N winds and falling temperatures to develop . On Monday highs will be near 20° with Tuesday's high in the low 20s, but wind chills will make it feel like it is in the teens. Needless to say these daytime temperatures are below normal.

As for Sunday, Monday and Tuesday nights we'll be in the brrrrr zone. Monday night will be the coldest one with single digit minimums, even subzero readings for the colder locations especially north of Albany (Hello Glens Falls and the Adirondacks!) while the other two nights will feature teens.

The reason for the turn to much colder weather: Refer to figure 1 (below). The jet stream forecast for Monday (Jan 4th) indicates a trough ( dashed yellow line) and the polar jet (blue colored area west of the trough) amplifying across eastern Canada and the Northeast corner of the U.S.. The jet stream winds ares blowing from the polar regions of North America down toward the Northeast. (One could even say the flow is cross-polar, blowing from Siberia to arctic Canada then down towards us.) This jet stream pattern is near perfect for delivering cold air our way.
Fig.1 Jet stream forecast for Mon 4 Jan 2016
By midweek moderation ensues as the cold high pressure cell moves to the East Coast on Wednesday (Fig.2) then slides offshore thereafter. Look for readings to warm back into the 35° to 40° range Wednesday through next Friday.

Fig.2 Surface forecast for Wed AM 6 Jan 2016



But by late next Friday (Fig.3) cold air will begin to press south out of eastern Canada. At  the same time a split flow jet stream pattern develops. We'll have two jet stream across North America, one from central Canada to the Great Lakes and Northeast - the polar jet (PJ) and a southern the jet or subtropical jet (STJ) blowing across the southern US to the Southeast Coast. The jets will be amplifying or getting stronger, especially the STJ.





WPC Surface forecast for Fri AM 8 Jan 2016


This sort of a split and amplifying jet stream pattern can lead to an active  pattern of unsettled weather developing, i.e., potential winter storms, especially with low pressure systems developing beneath the STJ (Fig.4). 
Fig.4 WPC surface forecast for Sat 9 Jan 2016


Now I am not saying we will see a winter storm here but  I am saying that there will be potential threats to watch.  So for snow lovers your hopes can be raised,and  for those who wish otherwise, come  its winter and you live in the Northeast!