A slow-moving disturbance will spread downpours across the Ohio Valley through Monday before impacting the mid-Atlantic during the new week.
The showers and heavy thunderstorms that this disturbance delivers will raise flooding concerns once again in the same areas impacted by flooding rain earlier in the week.
While a separate zone of flooding rain soaks North Dakota through Saturday evening, a cluster of drenching showers and thunderstorms will spread from the mid-Mississippi Valley to the lower Ohio Valley into Sunday.
The cluster will track eastward to West Virginia on Monday.
Cities in the path of the downpours include St. Louis; Cincinnati; Louisville, Kentucky; and Charleston, West Virginia. The threat even expands southward to Nashville.
The storms should then spread to the mid-Atlantic, potentially including Washington, D.C., Baltimore and Philadelphia, Monday night through Tuesday.
Along its journey from the Ohio Valley to the mid-Atlantic, the cluster of drenching showers and thunderstorms may trigger pockets of flash flooding. That is especially true in low-lying and poor drainage areas.
According to AccuWeather.com Chief Meteorologist Elliot Abrams, the danger is that we're going to have very steamy air to the south and cooler air to the north. This can lead to some episodes of thin bands of extremely heavy rain that can cause flooding.
Abrams warns that there could be situations early next week similar to what happened in New York earlier this week when central Long Island received around a foot of rain while New York City itself received less than an inch of rain.
Storms of this nature that dump several inches of rain in just a few hours can result in tremendous flooding on roadways near bodies of water and cause extensive travel delays.
One factor that will contribute to the flooding risk is the heightened soil moisture from the recent rain.
Whenever it rains, the ground acts like a giant sponge soaking up the rainwater. However, when the ground becomes saturated with water, any additional rain that falls runs off into nearby streams and rivers rather than being absorbed and, in some cases, can lead to flash flooding.
This may be the case in areas across the Midwest and mid-Atlantic that have received several inches of rain in the past few days, including Baltimore.
Those looking forward to the next spell of dry weather may have to wait as showers and thunderstorms remain in the forecast for portions of the Midwest and Northeast through the second half of the new week.
Fortunately, it does not appear like many of the thunderstorms will produce widespread severe weather across the regions. However, a few isolated cases of gusty winds or small hail cannot be ruled out.
The storminess will hold down temperatures prior to a surge of summer heat that is expected later in the month.
The risk of flooding from Odile will spill onto Texas and parts of the southern and central Plains late this week into the weekend.
On Tuesday, Edouard became the first major hurricane in the Atlantic since Sandy. While Edouard remains at sea, rough surf will reach some Atlantic coast beaches.
Moisture from Tropical Rainstorm Odile will deliver torrential rainfall and cause life-threatening flooding over the interior Southwest through the balance of the week.
The chilliest air of the season so far will settle over much of the Northeast Thursday into Friday and will bring frost to a large area.