NYC Weekend Weather – Jan 22, 2021

A cold and breezy start to the weekend with a cold front ushering in below average temperatures mostly in the mid-30s. High pressure builds and keeps things dry during the weekend. However, the upper-level pattern shifts to allow a shortwave trough to push through early next week, leading to a storm that could bring some accumulating snow overnight Monday into Tuesday.

Rest of today – partly cloudy with high temperatures in the low-40s. A moisture-starved cold front will work its way through the region. The main impact of this front will be to induce a shift in winds to the northwest, and trigger some decent cold air advection. This will lead to overnight temperatures plummeting into the mid-upper 20s.

Weather Prediction Center surface forecast for 7AM Saturday

Saturday – high pressure builds in behind the cold front, giving us a mostly sunny day. This high pressure and a low off to the northeast over the Canadian Maritimes will lead to a fairly tight pressure gradient, and the result should be breezy winds from the northwest, sustained in the range of 15-20 mph at least. So despite the sun, the cold start to the day will lead to temperatures in the low-30s and a much colder feel with wind chills around 20ºF. Overnight lows will be the coldest in quite some time, in the low-20s.

Sunday – windy conditions continue at least part of the day with high temperatures in the mid-30s. Once the center of the high moves over us, winds should subside. Overnight lows in the mid-20s with clouds building in.

GFS model 500 mb height and vorticity animated loop valid 7PM Sunday through 7PM Monday, showing a de-amplifying shortwave trough ejecting from the southwest towards our region.

Monday as the high pressure eventually moves off, a shortwave trough will be progressing towards our region. The accompanying surface low will bring mostly cloudy skies. Temperatures should peak in the mid-30s. Overnight, the storm is positioned to possibly bring us some light accumulating snow. Currently, it’s hard to pin down a total, but the following images from GFS and ECMWF models suggest something on the order of 3-5″ is possible. Low temperatures in the upper-20s should support all snow during this event, so storm track will be key here.