Friday 9 a.m.
The video explores how the weather should unfold this weekend and early next week. While longer-range models show cold air building in Canada and moving south later next week, no snow or freezing weather is in the forecast for the Northeast for the next 10 days.
Nadine has been a fixture over various parts of the open Atlantic for weeks now, and it is likely to still be on the map at the start of October.
Note how the satellite coverage ends over the eastern Atlantic. The satellite that had monitored much of the U.S. and Atlantic Ocean malfunctioned earlier this week. The geostationary satellite that had been monitoring the western U.S. and the Pacific was moved east to make up for some of the lost coverage, but you can see the eastern edge of its picture taking ability from its newest location.
Looking at next week, the GFS ensemble spaghetti plot of upper air winds shows how much agreement there is among members of the ensemble (same model running multiple times using slightly different starting assumptions). The maps are from next Tuesday, Nov. 25, and Thanksgiving Day, Nov. 27. There is good agreement on the first map, but a lot of spread two days later.
The location of lake-effect snow bands is tightly controlled by geography, topography and wind. From this pressure analysis, we see why the wind favored heavy snow staying south of the hardest hit Buffalo snow belts earlier today.
If this timing works out, there would be good travel weather for the Northeast Corridor on Wednesday while snow showers cross the Great Lakes and reach the northern and central Appalachians.
This map from one of my tweets yesterday (accuElliot) showed the wind direction most favorable for heavy lake-effect snow in and near Buffalo. Just a minute change in direction greatly affects the location of the heaviest snow, almost as if you were operating a fire hose. The snow is so deep (more than 4 feet in spots and deepening) that officials were considering the use of high lift equipment to extract vehicles.
It suggests rain in the I-95 corridor and snow from the mountains of West Virginia and Pennsylvania to southwestern Maine. Other models and ensemble versions will be examined this weekend as we narrow down the uncertainties associated with this fast-moving storm. Whatever the form of precipitation, you can count on another shot of cold air behind it. Lake-effect snow will be common as well.
I can see how slippery spots can develop from Philadelphia's northern and western suburbs on northeastward. The highest amounts of snow may be from Boston's western and northern suburbs on through Portsmouth, Portland and Augusta. Some spots could get 3-4 inches. Be ready for a slow commute tomorrow morning. If these problems develop, they could occur rather suddenly.