Wednesday marks the official start of the Atlantic hurricane season, and, like clockwork, the first tropical depression or named storm is on the verge of forming.
The potential storm would be born from showers and thunderstorms that are grouped just east of the Yucatán Peninsula and are expected to consolidate into a more concentrated area of low pressure as they shift north and east over the Gulf of Mexico in the coming days. The remnants of Hurricane Agatha, which slammed into southern Mexico on Monday as the country’s strongest May storm on record, are being drawn into this system.
The National Hurricane Center says the system has an 80 percent chance of becoming a tropical depression or storm by the weekend. Through Thursday, it is forecast to unload heavy rain on southeastern Mexico, the Yucatán Peninsula and Belize. Then South Florida, the Florida Keys and western Cuba could be in the crosshairs of very heavy rain Friday and Saturday.
Gusty winds and an ocean surge also are possible in South Florida, assuming that a tropical storm forms; environmental conditions probably will not support a hurricane.
The evolution of the potential gulf storm
The developing system will get a boost from what’s left of Agatha, which made landfall on Monday afternoon near Puerto Ángel on the west coast of southern Mexico. It struck as a Category 2 hurricane with 105 mph winds. The storm’s winds and ocean surge littered roads with debris and caused significant damage in the coastal towns of Puerto Ángel and Mazunte.
I'm back. Every now & then I hunt down a #hurricane that brings me to my knees, demands respect, reminds me why I do this. Behold: The Wrath of #AGATHA. Got right-front-quadded by classic deep-tropical buzz saw, in Mazunte #Oaxaca #Mexico. Machine-like power; deafening roar. pic.twitter.com/H2kWF0EBP1— Josh Morgerman (@iCyclone) May 31, 2022
The storm was forecast to produce 10 to 20 inches of rain as it transited the high-altitude terrain over the Mexican states of Oaxaca and Chiapas on Monday and Tuesday. At least 11 people died and 20 were missing from the resulting flooding and mudslides, according to the Associated Press.
Crossing southern Mexico, Agatha weakened from a hurricane to remnant thunderstorms. These remnants are being drawn into the Central American Gyre, positioned over the Yucatán Peninsula, the western Caribbean and the Bay of Campeche in the southern gulf. The gyre is a general area of counterclockwise spin in the atmosphere with showers and thunderstorms.
That spin is expected to become more concentrated in the days ahead while it slips between Cancún and the western tip of Cuba, probably pinching off into a new vortex that could become a tropical depression. That’s the precursor to a tropical storm. If whatever materializes produces sustained winds of at least 39 mph, it will be named Alex.
What’s to come
Water temperatures in the Gulf of Mexico are running a degree or two above average, and hostile high-altitude winds should slacken near and south of the low-pressure center. That could foster very gradual development, and the system could become a tropical storm by early Saturday. Around that time, it should be moving ashore in South Florida or slipping near the Keys.
Much of the heavy rainfall may occur north of the storm’s center and should arrive over the Florida Straits and the southernmost counties of the Florida peninsula Friday morning. Most of the rain will exit near the Bahamas late Saturday.
The European model simulates a broad 5 to 8 inches of rain south of the Caloosahatchee River and Lake Okeechobee, but the American model hints that localized totals in the double digits could be within reach.
The National Weather Service warns that the ground in South Florida is already “somewhat saturated” from several inches of rain over the Memorial Day weekend and that additional downpours “could lead to some flooding.”
If a tropical storm forms, it may thrust enough ocean water toward the coast to produce a surge, causing coastal flooding — especially around high tide.
An isolated tornado or waterspout would be possible, too, in the right front quadrant of the storm or zone just to the northeast of the center in any rain squalls.
Longer-range models suggest the storm may parallel the southeast coast and pass near or east of the Gulf Stream and intensify as it sweeps northeast over the open North Atlantic, but confidence for that scenario is low.
The start of the Atlantic hurricane season
June 1 marks the beginning of the annual Atlantic hurricane season, and atmospheric scientists have warned that 2022 could be the seventh straight year of above-normal storm activity. The presence of the climate pattern La Niña, which favors enhanced rising motion and calm upper-level winds favorable for hurricane development, could supercharge the season.
The National Oceanic and Atmospheric Administration projects 14 to 21 named storms — compared with 14 in an average year — and three to six major hurricanes rated Category 3 or higher.
Jason Samenow contributed to this report.