Watches & warnings (when active) issued by the Storm Prediction Center & the National Weather Service

Tropical Storm Bertha made made landfall on the coast of South Carolina today, tracking inland through to North Carolina and Virginia with forecasters anticipating potential flooding rainfall.

The Weather Channel reports: “Bertha made landfall with maximum sustained winds of 50 mph just to the east of Charleston, South Carolina, at 9:30am EDT, according to the National Hurricane Center. This landfall occurred about one hour after Bertha quickly formed near the South Carolina coast this morning.

“A tropical storm warning remains posted along the South Carolina coast from Edisto Beach to South Santee River.”

Bertha was expected to track northwestward through South Carolina toward North Carolina and western Virginia through tonight, before it weakens quickly to “a tropical depression and a remnant low as it moves farther inland”.

“Despite that expected weakening, Bertha will bring soaking rainfall and possible flooding into parts of the Carolinas and Virginia through Wednesday night. Gusty winds will also accompany this system as it moves inland,” the report said.
“Rainfall totals of 2 to 4 inches (locally up to 8 inches) are possible from eastern and central South Carolina to southeast and central North Carolina and southwest Virginia.”

The National Weather Service issued flash flood watches for portions of central and eastern South Carolina, central North Carolina and western Virginia, where the ground was already saturated by recent rainfall, the report added.

Bertha will also produce dangerous surf and rip currents along the coasts of Georgia and the Carolinas on Wednesday. Beachgoers are advised to stay out of the ocean.

How Did Bertha Form So Quickly?

Flood Alerts Posted by the US National Weather Service

Bertha formed from a tropical disturbance we’ve been tracking since Memorial Day weekend near Florida. That disturbance brought more than a foot of rain in three days to Miami, where it triggered widespread street flooding on Tuesday.

Its circulation center became much better defined on Doppler radar as it approached the South Carolina coast on Wednesday morning. Buoy reports also indicated tropical-storm-force winds near that center of low pressure.

It was deemed a tropical storm by the National Hurricane Center since it had all the characteristics of a tropical storm. That includes a well-organized area of low pressure, collocated showers and thunderstorms and tropical-storm-force winds.

The report also noted that Monday and Tuesday’s two-day fain total “beat out that which fell during Irma in 2017, and the 48-hour total was the city’s heaviest since 2012”.

Charleston is another location where flash flooding and coastal flooding from high tides and storms are worsening due to climate change. Fortunately, T.S. Bertha’s track kept the strongest onshore winds confined to areas north and east of Charleston.

A corridor of flash flood watches stretches from Charleston up through central North Carolina and into southwest Virginia, where a narrow corridor of tropical rains is likely to deposit a widespread 1 to 3 inches of water, with more in South Carolina.

And given recent heavy rains and saturated soils, it won’t take much rain to fall in a short period of time to result in flash flooding.

While it’s a weak and brief tropical storm, this is the 2nd named preseason storm of 2020. According to meteorologist Philip Klotzbach, this hurricane season is the fifth on record since 1851 with 2 named Atlantic storms prior to May 27.

Forecasters are calling for a busy Atlantic hurricane season, with a 70 percent likelihood of 13 to 19 named storms, six to 10 of which will become hurricanes. Three to six of those could become major hurricanes of Category 3 intensity or higher.

An average season produces 12 named storms and six hurricanes, three of which intensify into major hurricanes.