Tropical Depression Mindy took the meteorological community by storm on Wednesday, catching forecasters by surprise as it quickly formed during the early evening hours. It made landfall as a tropical storm along the Florida Panhandle in the evening, unloading up to a half-foot of rain before shifting into Georgia overnight.

Mindy’s not alone. Larry, a Category 2 hurricane, is sideswiping Bermuda, bringing tropical storm conditions as heavy rain squalls and gusty winds lash the island. As rip current danger remains high along much of the U.S. East Coast, the hurricane’s impacts are being realized nearly a thousand miles away. A hurricane watch is even up in parts of the Canadian Maritimes, where Larry is headed.

A third disturbance to watch also may be developing in the Bay of Campeche and is set to saunter into the western Gulf of Mexico early next week. Regardless of whether it intensifies and eventually earns a name, very heavy rainfall is possible in parts of eastern Mexico and South Texas. Forecasters have been monitoring that closely.

The trio of systems comes just days ahead of the climatological, or historical, peak of the Atlantic hurricane season. Sept. 15, on average, marks the height of tropical activity in the Atlantic — and also represents a typical halfway mark.

The season has been active. According to Philip Klotzbach, a hurricane researcher at Colorado State University, the amount of atmospheric energy expended by tropical storms and hurricanes is already reaching the seasonal norm — while we have more than 2½ months left to go. And the back half of hurricane season could be quite busy.

Tropical Depression Mindy

We’ll file this one under “that escalated quickly.” The system that would become Mindy was a loose clump of haphazardly organized thunderstorms on Wednesday morning in the central Gulf of Mexico beneath a lobe of spin at the tail end of a cold front. By lunchtime, it was estimated to have 50-50 odds of developing. That was upgraded to “likely” odds during afternoon.

By evening, the National Hurricane Center declared Tropical Storm Mindy was born, as an ocean buoy just southeast of the center confirmed 40 mph sustained winds. The Hurricane Center also noted that Doppler radar at Eglin Air Force Base, northwest of Panama City, Fla., indicated winds near the center reaching tropical storm force. The system made landfall shortly after 9 p.m. on St. Vincent Island along the Florida Panhandle with 45 mph winds.

By sunrise Thursday, Mindy had devolved into a tropical depression, the bulk of the heavy rainfall removed well northeast of the center. The system was anchored in south-central Georgia near the Florida border.

Tropical rainfall rates exceeding three inches per hour are possible in the heaviest downpours, particularly along the Georgia and South Carolina coastline along a cold front hung up near the coast. The National Weather Service noted that totals of five inches or more are possible and expressed concern about “likely flash flooding,” particularly during the late morning hours.

Most of the heavy downpour activity will be relegated to the immediate coastline of the Carolinas and should push offshore by late evening. There is a remote possibility that Mindy reacquires tropical characteristics as it moves off the East Coast over the warm waters of the Gulf Stream.

When it formed Wednesday, Mindy became the 13th named storm of the 2021 Atlantic hurricane season. Since 1966, only four other seasons have had this many storms by Sept. 8, according to Klotzbach. Brian McNoldy, a tropical weather researcher at the University of Miami and a Capital Weather Gang contributor, noted that the average formation of the 13th named storm does not typically occur until Oct. 25.

Hurricane Larry

Tropical storm warnings are up in Bermuda as Hurricane Larry sideswipes the British overseas territory, bringing gusty winds, heavy rain and some minor storm surge. Larry was centered 210 miles east-southeast of Bermuda at 8 a.m. Eastern time but is a very large storm. That means tropical storm-force winds extend outward up to 220 miles from the center and are expected to clip the island.

Within Larry’s core, maximum sustained winds of 100 mph were whipping up ocean waves approaching 50 feet in height. Even far from the storm itself, marine impacts were reaching the coastal Lower 48.

“Significant swells from Larry will continue affecting the east coast of the United States and Atlantic Canada through the end of the week,” wrote the National Hurricane Center. “These swells are likely to cause life-threatening surf and rip current conditions.”

By Friday afternoon, tropical storm conditions will overspread parts of Newfoundland as Larry whips northward, with hurricane conditions likely on the Avalon Peninsula into very early Saturday. A quick inch or two of rain is possible, but the big story will be the wind and coastal erosion — gusts exceeding 80 mph are possible in places such as St. John.

Over the weekend, Larry will complete its extratropical transition, or metamorphosis into a strong mid-latitude system, and truck north toward Greenland. There, the storm is expected to generate snow.

Areas to watch

Meteorologists are keeping close tabs on a tropical wave east of Honduras that will meander northwest over the coming days. It gets to the Bay of Campeche north of the Yucatán Peninsula by Monday and might have a brief window for some minor development, but it will move inland over Mexico before having the opportunity to take advantage of the gulf’s warm waters.

Coastal Tamaulipas and Veracruz, Mexico, and much of the western Gulf Coast in the United States could see several inches of rain from the nascent disturbance, with off-and-on downpours into the start of the workweek.

Another tropical wave over Senegal could move near the Cabo Verde islands and has a moderate chance of development into early next week.

Jason Samenow contributed to this report.