Wednesday 10 a.m.
The high pressure area maintaining beautiful weather in the Northeast now will weaken and move east by the end of the week as a cold front from the northern Plains advances. The rain with the front will probably be more extensive coming into the Great Lakes than it will be when the front reaches the East Coast on Saturday.
If the front sails off the coast and another high pressure area builds in, another series of sunny days would follow. However, a system that caused flooding rain in Las Vegas late yesterday could proceed across the Southern states then come up along the Eastern Seaboard early next week. What's more, a separate storm system that will cross south-central Canada this weekend may support the development of a low pressure area and cold front that could cause showers in the East Tuesday or Wednesday whether or not the first feature gets involved.
So, while the fine weather could last into early next week, there are factors that could change the picture quite a bit. If you are working on a project that requires a few days of dry weather, I hope you are taking advantage of this week's sunny day streak. This video has more.
In the Middle Atlantic states, the peak of fall foliage season is a little more than a month away. The picture here is a preview.
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.