Tropical Storm Bonnie forms, on rare track toward Central America
A tropical rainstorm will bring gusty winds and flooding rain to northern South America late this week before it strengthens and takes aim at Central America this weekend.
The tropical rainstorm that AccuWeather forecasters have been monitoring most of the week made the transition into Tropical Storm Bonnie, the second named storm of the Atlantic hurricane season, on Friday. After taking an unusual track across the southern Caribbean and skirting along the northern coast of South America, the storm may now put a very unusual stamp in the history books after crossing Central America.
While Bonnie is gaining strength as it nears the east coasts of Nicaragua and northern Costa Rica with landfall expected Friday evening, forecasters say the window for it to become the first hurricane in the Atlantic has likely closed.
A satellite loop from July 1, 2022, shows Tropical Storm Bonnie forming in the southwestern Caribbean Sea.
As of 8:00 p.m. EDT Friday, the Bonnie was located about 80 miles (130 km) to the east-southeast of Bluefields, Nicaragua, and was moving swiftly toward the west at 17 mph (28 km/h). Maximum sustained winds were 45 mph (75 km/h) with tropical-storm-force winds extending outward 115 miles (185 km) from the center, according to the National Hurricane Center (NHC).
Prior to moving into the southwestern Caribbean, interaction with the northern coasts of South America hindered the system's ability to organize from a tropical rainstorm into Tropical Storm Bonnie.
Now situated over warm water and away from South America, Bonnie is expected to continue to gain wind intensity until it moves inland across far southern Nicaragua and northern Costa Rica Friday night. The storm is expected to make landfall as a tropical storm with maximum sustained winds between 50 and 60 mph (80 to 96 km/h).
A tropical storm warning remained in effect for the Caribbean and Pacific coasts of Nicaragua and northern Costa Rica as of mid-afternoon Friday.
Regardless of Bonnie’s final intensity, the storm will threaten parts of Central America with strong winds and flooding rainfall into Saturday. Portions of Nicaragua and Costa Rica will be the two areas at the greatest risk from this tropical threat.
The strongest winds from the storm are forecast to occur where the system makes landfall and along its direct path. Much of southern Nicaragua is expected to receive wind gusts on the order of 60-80 mph (100-130 km/h) late Friday into Saturday as the storm nears the coast. An AccuWeather Local StormMax™ wind gust of 100 mph (160 km/h) is possible near the point of landfall.
The heaviest rainfall of 8-12 inches (200-300 mm) is forecast to fall over a large portion of southern Nicaragua and northern Costa Rica, with an AccuWeather Local StormMax™ of 26 inches (660 mm). Even outside of the heaviest rainfall, widespread amounts of more than 4 inches (100 mm) of rain are expected across almost all of Nicaragua and northern Costa Rica.
Rainfall of this magnitude can cause major flooding issues if it comes down hard and fast enough. This scenario is exactly what forecasters are concerned about for the region.
Flash flooding is likely across the area, and torrential rain can quickly lead to mudslides, especially in the region's elevated terrain.
"While rainfall is expected to be excessive and the likelihood of flash flooding and mudslides is high, the fast forward motion of the storm should limit the duration of the rainfall and strongest winds to 24 hours or less in Nicaragua and Costa Rica," AccuWeather Senior Meteorologist Alex Sosnowski explained.
Matters could be made much worse if the storm were moving at a slower speed or were to stall out and unleash round after round of torrential rainfall over the same areas, Sosnowski added.
Bonnie has been rated a 1 on the AccuWeather RealImpact™ Scale for Hurricanes in Central America due largely to the anticipated flooding rainfall.
Have the app? Unlock AccuWeather Alerts™ with Premium+
As a rainstorm, Bonnie has already proved disruptive on its journey so far. The government of Venezuela on Wednesday closed schools and opened shelters while also limited air and ground transportation due to the threat of heavy rain, The Associated Press reported.
The island of Curacao ordered businesses to close and imposed a curfew that began late Wednesday morning, the AP reported. Power outages were reported in Trinidad & Tobago earlier this week due to the storm's passage.
Central America was badly impacted by two major hurricanes at the end of the historic 2020 Atlantic hurricane season. Hurricane Eta struck northeastern Nicaragua as a Category 4 storm on Nov. 3 and was blamed for at least 165 deaths in Central America.
Just about two weeks later, Hurricane Iota barreled into the coast of Nicaragua as a Category 4 storm on Nov. 16. Iota was blamed for at least 84 deaths across Central America, and the NHC estimated that the storm impacted 7 million people across the Caribbean and Central America.
After moving through Nicaragua and Costa Rica, the storm is expected to emerge into the eastern Pacific this weekend, likely sometime Saturday. AccuWeather forecasters say this type of development and storm track are highly unusual at this point in hurricane season.
"Usually, storms moving into southern Mexico or Central America are shredded by the higher terrain of the area and do not cross into the East Pacific," AccuWeather Senior Meteorologist Danny Pydynowski explained. "However, this storm is tracking so far south that it could accomplish this rare feat since it is forecast to travel over the narrower part of Central America with less terrain overall."
Since the storm is not expected to dissipate while crossing Central America, tt will retain the name Bonnie once it emerges in the eastern Pacific Ocean.
Conditions in the East Pacific are currently conducive for development, meaning that once the storm is able to cross into the basin, it will be able to strengthen. It is even forecast to become even stronger than its strongest level in the Atlantic basin and become a hurricane early next week.
The East Pacific basin has already had two hurricanes roar to life south of Mexico this season: Agatha and Blas.
"During June, there has never been a named tropical system in more than 150 years of records near the coast of South America during La Niña conditions," AccuWeather Senior Meteorologist John Feerick said. During a La Niña, cool waters over the eastern part of the tropical Pacific tend to alter weather patterns and knock down wind shear over much of the Atlantic basin. This tends to assist with tropical storm development over the Atlantic.
Since the record-keeping of Atlantic tropical systems began in the mid-1800s, only 25 storms have passed within 50 nautical miles of Aruba, according to data from NOAA. Of those 25 storms, only one brushed by the country during the month of June -- an unnamed hurricane on June 29, 1933.
.jpg)
.jpg)