Relentless downpours will continue to cause incidents of flash and urban flooding over the eastern third of the nation during the Independence Day week. There is also the risk of locally severe thunderstorms.
A stream of tropical moisture all the way from the Caribbean Sea to the Gulf of Mexico to the East Coast, Appalachians and neighboring areas to the west will continue the pattern of daily, if not hourly, torrential downpours in some cases.
Many locations have received two to three times their normal rainfall since June 1. The ongoing pattern this week has the potential to bring another 3 to 6 inches of rain. Some places may end up with 12 to 20 inches of rain for the 40-day period through July 10.
While widespread, major river flooding is not expected, low-lying unprotected areas are at risk to take on water in this pattern.
Downpours have already caused major flash flooding in some communities of Pennsylvania and New York. These sorts of flooding issues are likely to expand westward and could briefly visit some neighborhoods of major cities in the I-95 corridor.
The latest indications are the firehose effect of repeating showers and thunderstorms will migrate slowly to the west as the week progresses.
This means the most frequent downpours could move west of much of I-95 by Independence Day. It also would mean a greater chance of repeating downpours and flooding risk for areas from Mississippi and Louisiana to Ohio and Kentucky.
Meanwhile, folks on vacation and heading to the beaches from the Carolinas to Long Island and southern New England may get a little good news. Most of the rain would shift inland by midweek.
However, much of Florida and Georgia to upstate New York and northern New England would likely continue to get bombarded by frequent downpours. People camping in the Appalachians are likely to be in for a wet time.
Typical of early July, any thunderstorm that develops in such a humid weather pattern can be briefly severe, causing lightning strikes to cluster in a localized area.
A small number of places can be hit with winds strong enough to down trees and power lines. In a handful of cases, there can also be highly localized large hail.
While the frequency of the downpours may decrease later in July, the saturated state of the ground will represent an ongoing risk of flooding. The overall moist flow from the tropics is likely to continue.
Meteorologists Alyson Hoegg and Ben Noll contributed to the content of this story.