Sunday, January 23, 2022

Forecasters monitor rare out-of-season tropical development in East Pacific
By Ryan Adamson, Accuweather.com

The system of interest is about 1,000 miles to the east-northeast of Hilo, Hawaii. 
Photo by Kanoa Withington/English Wikipedia

Despite the calendar showing January rather than June, AccuWeather meteorologists are monitoring a gale-force area of low pressure for the potential to develop into an out-of-season tropical depression or storm in the eastern Pacific Ocean.

The system of interest is about 1,000 miles to the east-northeast of Hilo, Hawaii. This places the area of interest in an area within a northward bulge in the jet stream.

"A northward bulge in the jet stream is where a tropical system can develop, especially during the warm weather season," explained AccuWeather Senior Meteorologist Alex Sosnowski.


Image from the AccuWeather Enhanced RealVue trade satellite showing an area of showers and thunderstorms over the Pacific Ocean early on Friday morning.

Since it's the middle of winter in the Northern Hemisphere, rather than the middle of summer, this may limit the ability of the system to develop. In addition, wind shear is already affecting the system.

"The system was being subject to significant wind shear right out of the gate, and that is likely to increase this weekend," Sosnowski said.

Although the likelihood of further development is low, it is not zero.

"There seems to be a brief window for the system to gather enough closed circulation to become a tropical or subtropical depression and storm prior to this weekend," said Sosnowski. "There continued to be strong thunderstorms erupting near the center of the disturbance early Friday morning, but no further organization was visible, he added.

Given the location of the shower and thunderstorm activity, it is not an immediate threat to land. In fact, the projected westward to southwestward movement will mean that is not expected to ever any land areas.

Regardless of development, any shipping interests in the area can expect to experience rough seas and large waves, forecasters say.

The National Hurricane Center gives the system only a 10 chance of development over the next 48 hours as of early Friday.

Despite January being well outside of the traditional tropical season, development has happened several times in the Pacific Ocean during the first month of the year.

"The most recent January storm was Category 2 Hurricane Pali, which spanned from Jan. 7 to Jan. 15 in 2016," AccuWeather meteorologist and senior weather editor Jesse Ferrell said.

Not only was Pali the most recent hurricane, but it also holds the record for the earliest storm in the calendar year. However, it is not the strongest.

"The strongest storm was Category 2 Hurricane Eneka in 1992, which lasted from Jan. 26 to Feb. 9, becoming a Category 3 in February," Ferrell noted.

Both of those storms occurred in the Central Pacific basin, which is the portion of the Pacific between 140 degrees and 180 degrees west longitude. The current disturbance is to the east of 140 degrees west, where development is even rarer during this time of year.

For the East Pacific basin only, Tropical Storm Andres last year on May 9 was the earliest-forming named storm, while Tropical Depression One-E, on Apr. 25, 2020, was the earliest-forming depression according to Ferrell.

The official start of hurricane season in the East Pacific does not occur until May 15. The first name on the list for storms in the East Pacific this year is Agatha.

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