Thursday 9 a.m.
Thunderstorms that caused damaging winds in south-central Pennsylvania yesterday afternoon weakened as expected as they approached the I95 corridor. Cooler air follows the front, particularly in the Great Lakes region, where temperatures started the day well down in the 30s. A pocket of cold air aloft helped spawn showers over Wisconsin and Michigan overnight and this morning. In addition to some showers, there could be a thunderstorm at some spots farther east later today.
High pressure will strengthen over the Eastern states tomorrow and Saturday, then probably migrate to a location east of New England later Sunday into early next week. The resulting flow from the ocean can cause low-level moisture to increase, producing clouds and perhaps drizzle or a bit of rain in the Middle Atlantic states (less likely in New England). 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.
If the ridge was the only thing involved, it would just be sunny hot and humid day after day. As it is though, there are various minor disturbances rippling through the ridge. One such disturbance has allowed cooler air to spread down the coast.
This map shows where the storms were at 10:18 AM ET. That cluster of storms may hold together, but in response to daytime heating, new ones can pop up at other places this afternoon.
On this map, two such features (short waves) stand out today. The one in Ohio caused some thunderstorms in Michigan and Indiana yesterday. The other short wave is causing thunderstorms this morning from western Wisconsin to northern Missouri.
Scotty the Dog will be four-months-old in four days. On walks during hot weather, he is quick to seek out shady spots. He has yet to experience any cold weather, but he looks like he will be ready when it arrives (not any time soon!).
Erika's heavy rainfall separated into two areas yesterday. This is the Morehead City, North Carolina, radar, showing an area of heavy rain and thunderstorms that dumped more 4 inches of rain on parts of the coastal Carolinas this morning.
Tropical Storm Erika could eventually affect Florida and other sections of the Gulf Coast or Southeast, but for now it poses no threat for the Northeast. This map shows the storm as of early this morning.