Several batches of slow-moving showers and thunderstorms will spread the threat of flooding from Kentucky to Tennessee into Monday. The storms will continue to push eastward into areas including West Virginia, Virginia, Maryland and Delaware during the early part of this week.
Local rainfall amounts of 1 to 2 inches will occur in just a few hours, which is enough to flood some roadways and low-lying areas.
Umbrellas will be put to good use as the cluster of soaking showers and storms progresses eastward, affecting cities such as Nashville and Knoxville, Tennessee; Lexington and Louisville, Kentucky; Cincinnati, Ohio; Charleston, West Virginia; and Roanoke, Virginia.
Storms with heavy rain were also dipping farther south into northern Mississippi and Alabama.
Although more localized, storms with heavy rain will once again develop Monday along the Gulf Coast states from Louisiana to Georgia, AccuWeather.com Meteorologist Carl Erickson said.
Besides producing flooding, a few of the storms can turn gusty and strong into Monday, so watch for rapidly changing conditions.
On Monday, heavy showers and thunderstorms will extend along the I-81 corridor from Winchester, Virginia, to Bristol, Tennessee.
The cluster of drenching showers and thunderstorms will eventually reach the coast of the mid-Atlantic by Tuesday with the heaviest rain affecting a swath of the I-95 corridor from Baltimore to Raleigh, North Carolina.
AccuWeather Senior Meteorologist Kristina Pydynowski warns that these storms can create travel delays as they move through, especially on the roadways. This includes the Tuesday morning commute for those in the mid-Atlantic.
"Even if flooding fails to ensue, the downpours would create hazards to motorists by dramatically reducing visibility and heightening the risk of vehicles hydroplaning at highway speeds," Pydynowski said.
Those traveling I-81 in Pennsylvania and I-95 in New Jersey can expect weather conditions to slowly improve as high pressure promotes dry weather farther to the north over the Northeast.
One hundred miles may be all that stands between a zone of sunshine and an area that has clouds and rain for a good portion of Monday in the mountains and Tuesday near the coast.
The mid-Atlantic will remain the focal point of showers and thunderstorms through midweek, Unsettled weather will expand into more of Pennsylvania, New Jersey, New York state and New England Wednesday and Thursday.
Although the flood threat is not expected to be as high on Wednesday and Thursday, travel delays and impacts on outdoor events could occur.
A cold front will ignite severe thunderstorms from eastern New England to the Delmarva Peninsula on Tuesday in the third consecutive day of unsettled weather for the region.
Hawaii will escape the worst, but not all of Guillermo's impacts as the tropical storm passes north of the islands Wednesday through Thursday.
A fall-like cooldown is in store through the end of the week for the Northeast.
Public officials are in the process of eliminating Naegleria Fowleri, a brain-eating amoeba, from two drinking water supplies in Louisiana.
Lake Erie is once again turning green due to algal blooms that peak during high water temperatures.
Casper, WY (1990)
A total of 0.84" of rain. The normal rainfall for all of August is 0.63".
Alexandria, VA (1992)
80 mph wind gust from a thunderstorm.
Flathead Lake, MT (1995)
5-6 foot waves from a distant thunderstorm damaged boats, sea walls, and docks.