Live updates: System dumping rain on MS Coast may not become tropical storm
South Mississippi watches and waits Friday as Potential Tropical Cyclone 3 continues to organize and move across the Gulf Coast.
11 p.m. - First Tornado Warning
The first Tornado Warning was issued in Hancock County until 11:45 p.m., after several waterspout warnings in the Mississippi Sound.
A Tornado Warning was issued for D’Iberville, Gulf Hills and Woolmarket as well as Pearlington and Ansley until midnight; Pass Christian and Delisle until 1 a.m.
A Flash Flood Warning continues until 3:15 a.m. for areas in Hancock County including Diamondhead, Waveland, Bay St. Louis and Pearlington as well as Slidell and Pearl River in Louisiana and Pascagoula-Gautier until 4:45 a.m.
10:30 p.m. — Flash flooding a concern for MS Coast, AL, FL
A flash flood warning is in effect in southern Hancock County and western Harrison County until 2:15 a.m. Saturday as Potential Tropical Cyclone 3 dumps rain across the Gulf Coast.
The National Weather Service in Mobile tweeted it was becoming “increasingly concerned about a significant flash flood threat setting up across portions of southeast MS, southwest AL and the western FL panhandle.
Rainfall rates could exceed 2 to 3 inches per hour at times, and winds will gradually increase overnight, the NWS said.
10 p.m. — NHC: System may not become tropical storm
The National Hurricane Center said in its 10 p.m. update said that Potential Tropical Cyclone 3 is no longer expected to strengthen into a tropical storm as earlier predicted.
There is no significant change to the forecast track at the 7 p.m. update from the NHC. A tropical storm warning remains in effect for all 3 Coast counties.
The system is expected to make landfall over the northern Gulf Coast sometime in the next 6 hours.
“Regardless of its status, heavy rains and tropical-storm-force winds are spreading across portions of the northern Gulf Coast, and these conditions will spread inland through tonight,” the NHC said.
The system was about 60 miles south-southeast of Morgan City, Louisiana, and is moving north at 13 mph.
Time is running out for the system to develop, “However, it should be noted that in this case landfall will not instantly put an end to the chances of tropical or subtropical cyclone development, as much of the associated strong winds and convection will remain over water for at least 12 hours,” the NHC said.
Three rivers in Harrison County are expected to crest above flood level on Sunday morning:
- Biloxi River, forecast to crest at 16 feet, with flood stage at 12 feet
- Wolf River, forecast to crest at 10 feet, with flood stage at 8 feet
- Tchoutacabouffa River, forecast to crest at 13.5 feet, with flood stage at 8 feet
9:30 p.m. — Heavy rains coming in
Heavier bands of rain from the system are starting to move over the Coast, particularly in Hancock County and western Pass Christian, the National Weather Center radar shows.
Harrison and Jackson counties are also seeing rain pick up as the system moves inland.
The next update is at 10 p.m.
4 p.m. — Latest NHC update
Potential Tropical Cyclone 3 remains an unnamed storm, and there is no significant change to the forecast at the 4 p.m. update from the National Hurricane Center.
“There is some opportunity for a little strengthening during the next 6 to 12 hours before the system makes landfall,” the NHC forecast discussion says. “However, significant intensification is not expected due to the cyclone’s broad and asymmetric structure, and ongoing west-south westerly vertical wind shear.”
The storm is about 125 miles south of Morgan City, Louisiana, and 270 miles southwest of Mobile, Alabama, and is moving at 16 mph. It has sustained winds of 45 mph with higher gusts.
A Tropical Storm Warning is in effect from Morgan City to the Okaloosa/Walton County line in Florida.
Rainfall totals of 4 to 8 inches, with isolated maximum amounts of 12 inches across portions of the Central Gulf Coast, are expected.
The next update is at 7 p.m.
Officials said at a meeting Friday afternoon at the Harrison County Operations Center that river and flash floods in low-lying areas are the biggest threat from the tropical weather.
All of Harrison County’s rivers are expected to crest well above flood stage, but people living on those rivers are familiar with the situation.
Harrison County Emergency Management Agency Director Matt Stratton said, for example, the Biloxi River was at 3 feet Friday at the Three Rivers Road bridge and is expected to crest at 16 feet Saturday night. Flood stage is 12 feet.
The primary risk of flooding will be Saturday and into Sunday on the rivers, Stratton said.
2:30 p.m. - Storm starts to arrive
The skies are darkening as radar shows the bulk of the storm is starting to move over the Mississippi Coast.
Potential Tropical Cyclone Three is still moving north at 14 mph and winds have increased to near 45 mph, the National Hurricane Center said at 1 p.m.
The National Weather Service in New Orleans said winds of up to 51 mph have been detected offshore.
Tropical storm-force winds extend up to 200 miles from the center of the storm, the NHC said.
Landfall is still expected overnight.
Chevron said it has temporarily halted production at two oil and gas platforms and evacuated some staff ahead of the storm. Other facilities in the Gulf are operating at normal levels.
10:15 a.m. - NHC updates warnings
Heavy rain and gusty winds are beginning to reach portions of the northern Gulf Coast, the National Hurricane Center said in its 10 a.m. update.
Officials in Biloxi and cities across the Coast are declaring a state of emergency ahead of the storm.
The Tropical Storm Warning has been discontinued for parts of the Louisiana coast — from Morgan City to Intracoastal City.
A wind advisory has been issued for some upper counties in Mississippi: Pearl River, Stone, George, Greene, Perry, Wayne, Amite, Pike and Walthall counties. Wind gusts up to 35 mph are possible.
The system is moving at 14 mph toward the north-northeast, and that the forecast track puts landfall along the north-central Gulf Coast on Friday night or early Saturday.
The Air Force Hurricane Hunters, based in Biloxi, are flying through the storm. Estimated minimum central pressure, based on data from the Hurricane Hunters and surface observations, is 1007 mb (29.74 inches).
The system has a 90% chance of becoming a subtropical or tropical storm later today.
The NHC forecasts rainfall totals of 4 to 8 inches, with isolated maximum amounts of 12 inches.
10 a.m. - River flooding
Those living along the rivers in South Mississippi need to be especially aware of the weather this weekend as a Flood Warning is issued ahead of the tropical storm.
Rob Dambrino, deputy emergency management director in Harrison County reports the three rivers are expected to crest Sunday morning, well above flood stage.
As of Friday morning:
Biloxi River: measured 2.4 feet. Forecast to crest at Sunday morning at 16 feet.Flood stage is 12 feet.
Wolf River: measured 3 feet. Forecast to crest Sunday morning at 10 feet. Flood stage is 8 feet.
Tchoutacabouffa River: measured 1.94 feet. Forecast to crest Sunday morning at 13.5 feet. Flood stage is 8 feet.
9 a.m. - Sandbags available
Matt Stratton, working his first tropical storm as the new director of Harrison County Emergency Management Agency, said residents should have storm preparations complete this morning, since rain will begin in earnest later today.
“We really encourage people to asses the situation throughout the day,” he said, and try to limit travel this evening.
Sandbags are still available at many locations, he said.
The National Weather Service just issued warnings for river flooding, he said, and a Coastal Flood Warning and a Flash Flood Watch begin at 1 p.m.
8:30 a.m. - Gulf Coast meteorologist’s forecast
The northern Gulf Coast will start to feel the effects of the feeder bands later today, said meteorologist Rocco Calaci, “and tomorrow looks like a very wet day for East Louisiana, all of Mississippi and Alabama, plus the Florida Panhandle from Pensacola to Santa Rosa Beach.”
The National Weather Service in New Orleans reported Friday morning that widespread flash flooding remains the main concern, and a Flash Flood Watch is in effect for the entire area.
Tropical Storm Warnings are up for South Mississippi and the system could reach minimal tropical storm strength when it nears the coast of Louisiana at around 1 a.m. Saturday, said Calaci, who focuses on Gulf storms.
“With this tropical low moving, we are finally seeing some development on the east side of the circulation, and this is going to result in a lot of rain for the northern Gulf Coast from this afternoon to early Sunday,” Calaci reported.
The models differ on how much rain will fall this weekend on South Mississippi, with the GFS model showing 12-16 inches possible in Mississippi, he said, while the ECMWF model shows 12-20 inches possible for coastal Mississippi.
“Either way, there will be widespread flooding problems for the northern Gulf Coast,” he said.
“As the storm hits land, the probability of any tropical storm force winds will be confined between Slidell Louisiana and Biloxi Mississippi,” he said. “Most of the affected region will have sustained winds 20 to 25 miles per hour and gusts as high as 40 miles per hour.”
Waterspouts and tornadoes could develop as the feeder bands move onshore.
The Sun Herald will continue to provide updates throughout the day.
This story was originally published June 18, 2021 at 8:33 AM.