Tropical Storm Bertha’s Moisture Sparks Flood Threat Across the Southeast

After making landfall in southeast Louisiana on July 22, Tropical Storm Bertha moved westward along the Gulf Coast before dissipating over Texas on Thursday evening. Unfavorable upper-level winds left the storm’s heaviest rain and strongest winds over the Gulf, limiting direct impacts on land. However, a plume of the storm’s moisture became trapped on a slow-moving front that later stalled, directing abundant rain into the Southeast and southern Virginia beginning Wednesday.

CNN

Forecasters have placed a Level 3 of 4 flood-risk area across southeast North Carolina and coastal-central South Carolina through Friday night, covering cities such as Wilmington, NC, and Charleston, SC. A Level 2 risk extends to Atlanta, GA; Birmingham, AL; and Greenville, SC, persisting into Saturday with the possibility of additional heavy-rain rounds.

CNN

Rainfall rates of three inches per hour or more could overwhelm the region’s dry soils, which are still recovering from severe to extreme drought. Spot totals of five inches or more are possible—roughly a month’s worth of rain for locations like Myrtle Beach, SC (average 5.40 inches in July). Earlier this week, isolated storms dropped up to six inches in 12 hours in Greensboro and Winston-Salem, NC, and five inches in a few hours north of Knoxville, TN, prompting flash-flood warnings.

CNN

The North Carolina Department of Transportation reported that flooding temporarily closed a short segment of Interstate 40 northwest of Durham on Thursday morning. Along the Gulf Coast, beach conditions were hazardous and minor coastal flooding occurred, with vehicles partially buried in sand on Dauphin Island, AL. Wind gusts exceeded 40 mph at New Orleans Lakefront Airport during the storm’s approach.

CNN

The lingering moisture plume is expected to continue producing heavy rain into the weekend, especially if the stalled front remains in place. While the rainfall could alleviate the ongoing drought, rapid, intense downpours risk flash flooding in low-lying areas and on already saturated urban streets. Residents in the highlighted risk zones are advised to monitor local forecasts and heed any flash-flood warnings that may be issued.

CNN