It’s been a very wet week so far across most of the East Coast, and more rain is ahead this weekend. Flood Watches are in effect for numerous states in the Mid-Atlantic, as several more inches of rain fall on top of the already saturated ground. River levels are also rising, and some locations will be threatened by moderate to perhaps major flooding beginning on Friday. This is all thanks to a stagnant upper-level pattern with high pressure off the coast, directing the deep tropical moisture up the East Coast from the Caribbean Sea. There are also continuous rounds of low pressure that have been moving along a stationary front draped over the Mid-Atlantic. By the end of this weekend, however, that front will become a warm front, tracking northward toward New England as low pressure kicks it out.
On Saturday, the best chances for flooding rains will be in New England, coastal sections of the Mid-Atlantic, the eastern Carolinas, and South Florida. The day will be a washout across most of New York, New England, and eastern portions of the Mid-Atlantic. We’ll continue to see those rain and thunderstorms off the eastern coast of Florida flow into the Carolinas and the Mid-Atlantic. Widespread showers and storms will return to South Florida, which may trigger additional flooding.
Overnight Saturday, the steady rain will continue across northern New England. Otherwise, much of the Eastern third of the US will dry out with only some widely scattered showers around. Flooding concerns will remain in South Florida, however, due to slow-moving thunderstorms near the eastern coast.
Now on Sunday, precipitable water values will decrease, meaning that there won’t be as much moisture available in the atmosphere. Nonetheless, scattered showers and thunderstorms will still be around the East Coast region, from the Great Lakes down through the central Gulf Coast and all locations east of there. Localized areas may experience flooding, especially river flooding, but this concern should generally lessen for everyone on Sunday.
Next week, the pattern will relax a bit with continued diurnal showers and thunderstorms just affecting the Southeast, including Florida. These will be hit-or-miss, so not everyone will experience rain on a daily basis. There will be some heavier storms, but nothing like the widespread flooding rains seen at the end of this week. A surface low pressure will sweep through the Ohio Valley and Northeast Monday into Tuesday, which will bring an area of rain. A cold front will then push through, ushering in a drier air mass for this region for the remainder of the week.
In our rainfall forecast, you’ll notice a widespread area that can expect either two to three or three to five inches of rain. Some locations in the Mid-Atlantic will likely exceed five inches, while some towns in the Southeast will experience no rain. This is all due to the localized nature of many of these severe thunderstorms and rainfalls.