Cold Air Moving into the Northern Plains and the Northeast Over the Next 5 to 10 Days...

The latest GFS model runs continue to indicate nice weather for Thanksgiving over most of the nation. A cold front will advect cold air from central Canada this Saturday and Sunday. A 1000 mb - 500 mb thickness of 518 dm is forecast for NYC on Sunday at 12 Z. Light snow can be expected in the Great Lakes with lake effect snowfall possible. There could also be a few flurries in the NYC metro area. For the past week, the GFS has been forecasting that a storm will form near the Ohio Valley and then move northeast. The model has been forecasting different tracks for the resultant low that forms. In the latest run, the storm tracks into eastern Ontario spreading a large area of rain and snow to the Northeast on the 28th and 29th. Rain changing to snow would be expected in the NYC metro area under the current scenario. In the wake of this storm, the coldest air of the season will plunge across the Great Lakes and the Northeast with lake effect snows in upstate New York. A thickness of 514 dm is forecast for the NYC metro area on Saturday, Dec. 1st at 6 Z. The first day of December will really feel like winter according to the current model run. The first few days of December is forecast to be seasonably cold with a zonal flow at 500 mb over the eastern half of the country. A storm system is forecast to spread rain with snow at the higher elevations along the west coast and then down to California. As always, this long range forecast will likely change in the next few days. 
George Wright is a Certified Consulting Meteorologist for Wright Weather Consulting, LLC. George is also a meteorologist with ABC News and Cablevision News 12. Our website is WrightWeather.com.