Tropical Storm Julia forms and threatens hurricane Nicaragua


It’s been two weeks since the system that would become catastrophic Hurricane Ian passed through the Caribbean, and now it looks like a new tropical system may be developing in its wake. Newly formed Tropical Storm Julia is bringing heavy rains and gusty winds to northern Venezuela and Colombia, and could become a hurricane as it heads into Nicaragua this weekend.

Hurricane deaths have declined over time, but Ian has been a setback

Unlike its predecessor, Julia will not pose the threat of curving north and affecting the Gulf of Mexico or the Lower 48. The High over North America will act as a guardrail that will steer it more to the west.

But damaging to damaging winds will blow across the Nicaraguan coast over the weekend, with up to 15 inches of rain and the potential for “life-threatening” flash flooding and mudslides, according to the National Hurricane Center.

A hurricane warning is in effect for San Andres, Providencia and the Santa Catalina Islands in Colombia, with a hurricane watch in effect for the Nicaraguan coast between Bluefields and the Honduras border.

In the shorter term, a tropical storm warning covers Colombia from Riohacha to the Venezuelan border.

Until early September, tropical activity in the Atlantic was running at only about 10% of what is typical for a season so far; August was the first in 25 years to pass without a single named storm forming. Since then, Ian and Fiona have both peaked at Category 4 strength, and activity has spiked to 77% of average.

According to an ACE metric, or Accumulated Cyclone Energy – a figure that estimates how much energy storms expend as strong winds over their lifetime – September 2022 has been more active than September 2020 or 2021. .

Julia was classified as a tropical storm as of 11 a.m. Friday. Maximum winds were estimated at 40 mph in the core. The storm was 110 miles west of the northern tip of the Guajira Peninsula and was moving west at 18 mph.

By mid-morning, the NOAA GOES East weather satellite captured a burst of convection, or showers and thunderstorm activity. This is the sign of a reinforcement system.

An Air Force Reserve Hurricane Hunter aircraft investigating the system found winds of 38 mph, 1 mph less than tropical storm force, a few thousand feet above the ground. Considering the mission had just begun, the National Hurricane Center was confident that tropical storm-force winds must be present elsewhere inside the storm, and it was subsequently named Julia.

Julia was working to repel shear or a disruptive change in wind speed and/or direction with altitude. There are signs that the shear is expected to subside over the next 24 to 36 hours, allowing Julia to take advantage of the warm Caribbean Sea surface temperatures and intensify.

While ocean waters are warm enough to support strengthening, rapid intensification, as was the case with Ian, is not expected.

Ian had clockwise rotating high pressure, which helped vent air from the system at higher altitudes. This contributed to Ian’s exit; the more air a storm pushes out from above, the more its atmospheric pressure can drop and the more warm, moist air it can ingest from below. It helps to get stronger.

For Julia, the anticyclone will remain boxed in to the north and will probably not strengthen as quickly.

Additionally, Julia is drifting west faster than originally expected, limiting the intensification window. As such, it will likely make landfall in Nicaragua by Sunday morning. By then it should be a Category 1 hurricane. That means coastal gusts could reach 85 mph. A storm surge of 2 to 4 feet, or a rise in ocean waters above normally dry land, is also possible.

Far more concerning is the potential for torrential rains of 5 to 10 inches or more in parts of Nicaragua, Guatemala, Honduras and Belize.

The storm will dissipate into a remnant low as it tracks towards the Pacific early next week.

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