Thanksgiving Day 2021 for NYC shaping up to be the best weather of the week. High pressure will keep an approaching cold front at bay and provide warm, westerly downsloping winds that should push temperatures into the low-50s. Enjoy it while you can, because gusty rains will follow Thursday night with the cold front, then we’re looking at cold temps going into the weekend in the low-40s.

At the surface, high pressure will still predominate our local weather. This will keep rains at bay, while the shallow pressure gradient around the area will lead to light winds. The Thanksgiving Day Parade balloons will surely be flying high over the first spectators to view them since the pandemic started!

Looking at the forecast soundings at 8 AM Thursday, around parade jump off time, we can see that the boundary layer below 3000 feet should be relatively dry and cloud free, but it does appear that a deck of clouds will be in place from that 3000 feet up. Light winds of 5 knots or less are forecast in this case.

Once the cold front makes its passage overnight Thursday and into Friday morning, the mild weather will come to an abrupt end. Winds will pick up due to an increasing pressure gradient between the strengthening parent low associated with the front and high pressure building over central Canada. The winds should be effective at bringing about cold air advection, transporting this colder, drier continental polar airmass towards us over the weekend. This will result in high temperatures only in the low-40s, clearing skies, and wind chills in the 30s.