Thursday, January 20, 2011
Jan 20, 2011: Snow Tonight, Then Extreme Cold
***This post is from 2011. Please visit the MAIN PAGE to see the latest forecasts for January 2012.
Today brought mostly cloudy skies to the area as clouds moved in due to yet another storm approaching the area, which will produce a widespread moderate snowfall. While temperatures today were chilly across the area, they are about to get much colder as what may end up as the coldest air mass of this winter and the coldest temperatures since January 2009 affect the area this weekend, with parts of, if not most of the area failing to reach the 20 degree mark for highs.
Tonight And Tomorrow's Outlook: Moderate Snowfall
We are currently seeing widspread snow in Pennsylvania, associated with a low pressure currently near West Virginia. This low pressure will continue to move east northeast, and later tonight will be located off the coast, not too far SE of New York City. As the storm quickly moves northeast, moving over far eastern Long Island, it will intensify faster, and will likely be near 990 mb once it reaches Cape Cod in the early afternoon tomorrow. The storm will continue to rapidly intensify and organize itself, bringing heavy snow and wind to downeast Maine, where slightly over a foot of snow is expected. The storm will then exit the region, pulling down extremely cold air with it.
For the area, expect to see light snow spreading from west to east between 10 PM and 1 AM. The snow will be light at first, however as the low pressure moves near the area, moderate to locally heavy snow will fall between 4 and 7 AM for places near NYC and further west, and between 6 to 9 AM for the eastern parts of the area. The snow will then end from west to east in the morning for the western parts of the area, and in the early afternoon for the eastern parts of the area.
Expected Snowfall: When the storm ends, at least 4 to 6 inches of snow are expected in the western and central parts of the area, with the highest totals in the immediate NYC area being in the northern suburbs. The highest amounts across the area will be in southern Connecticut, where as much as locally 7-8 inches of snow are expected.
Looking across the rest of the region, the moderate to heavy snow axis will extend from the area into southern New England, where 5 to 10 inches of snow are expected, and as the storm continues to intensify, heavy snow will fall in downeast Maine, where the highest snow totals out of the northeastern US will be, with slightly over a foot of snow expected.
Weekend Outlook: Coldest Since January 2009
Over the last week, I occasionally hinted at the possibility that high temperatures may fail to reach the 20 degree mark in parts of the area this weekend and widespread single digit readings for lows in the colder case scenario, and this now appears to be reality with what will be the coldest weekend since January 2009, when highs across most of the area were in the 10s and low temperatures were in the single digits for most of the area.
The cold will come in two waves. The first wave will come on Friday night into Saturday, with low temperatures on Friday night expected to be in the lower to mid 0s inland, mid 0s to lower 10s for the north/west suburbs of NYC and southern Connecticut, upper 0s to lower 10s for Long Island, and lower to mid 10s for NYC. High temperatures on Saturday will be very cold, in the upper 10s inland, upper 10s to mid 20s for the immediate NYC area, and lower to mid 20s for the eastern parts of the area.
On Saturday Night, the cold will briefly weaken as a weak low pressure near the Great Lakes brings mostly cloudy skies and warmer overnight lows, in the mid to upper 0s inland and in the lower to upper 10s for the rest of the area. Sunday will be slightly warmer than Saturday, with clearing skies and high temperatures in the upper 10s to lower 20s inland and in the lower to mid 20s for the rest of the area, however this weak low pressure in the Great Lakes will reinforce the cold air, with even colder temperatures.
Sunday night may very well end up as the coldest night of the winter. Mostly clear skies are expected, and low temperatures are expected to quickly drop across the area. There is some slight uncertainty with exactly how cold it gets, but low temperatures below zero are expected in the western parts of the area, and have the potential of getting as low as -5 to -10 degrees. In the immediate NYC area, even New York City may reach the 10 degrees mark, if not drop slightly below 10 degrees, with the suburbs further north/west as well as southern Connecticut seeing low temperatures in the lower negative single digits to the mid 0s. Monday will be a very cold day, with high temperatures in the mid to upper 10s across the area with a few lower 20s possible.
Middle Of Next Week: More Significant Storm Potential?
For the middle of next week, the latest models are suggesting a more significant storm threat, however there is a wide spread of solutions at this time ranging from a storm tracking to the west of the area with a wintry mix, to a storm off the coast bringing a snowstorm for the area, to a storm staying out to sea. There is still uncertainty at this time, and I will discuss this storm in more information once details become clearer, however the storm is likely to affect the area with at least some precipitation at this time. Stay tuned for more information on this storm.
Posted by NYC Weather at 8:33 PM