Thursday 9:30 a.m.
The dreariness of yesterday morning in the Northeast has been replaced by dazzling sunshine and deep blue skies. A fast-moving cold front will send clouds streaming across the Great Lakes then New York and New England today and tonight, then a large high pressure area from western Canada will move for the start of the weekend. You can see and hear what this high pressure area should do in this video, along with what the flow behind it should accomplish later in the weekend.
In the short burst of cold air into the eastern Great Lakes tomorrow, showers will break out in the same areas that had them last night and this morning. Since this air mass is a little colder, snow showers are likely over the higher terrain southeast of Lake Ontario. Snow showers with lightning and thunder hit the Tug Hill Plateau last night, and the same thing can happen late tonight or tomorrow morning.
Severe thunderstorms are likely to break out in the middle of the country late tomorrow and tomorrow night, then rain and thunderstorms will advance into the Great Lakes for Saturday. A switch to a southwesterly flow aloft should keep the moisture mostly north of the Middle Atlantic states for much of Sunday... but as a cold front swings around a few showers should reach the area from southern New York to Virginia on Monday.
In most of the Northeast, it is a dazzling day, with the bright sun playing off the leaves that change hue by the day. It's quite a contrast from the dull dreariness much of the region experienced the first half of the week.
In the Northeast, a high pressure area now in control will be reinforced by another high from northeastern Canada. In the "what could go wrong?" department, a batch of cloudiness has appeared east of New England and has been spreading southwestward toward the New Jersey coast this morning.
The clouds over parts of the region are starting to break up, a sign that the predicted drier air from the northeast is making progress.
Cloudiness covers a large area. A few pockets of clearing show up where south winds ride downhill from mountains to lowlands. Air warms and dries with descent. Notice clearing downwind (northwest of) the Smoky Mts.
So, there could be more showers at times late next week as forest we can tell. For now we are stumped. But, it is our beleaf that this weekend you will like being outside. I know a dogwood. It may be a little cool for the beech, but you can take your dog for walk in the bark. What about next weekend? Don't ax.
If the pattern turns out damp as suggested by this map for Sunday, it could turn gray and drizzly from D.C. to New York City for early next week. If the high does not move offshore and no disturbance approaches from the west, it would be sunny and warm.
Two things stand out: (1) a warmup this weekend and early next week (the top graph), and (2) the overall dryness for the weekend and early next week. This graph is for Philadelphia.