Polo Puts on a Show Over the Eastern Pacific

The Big Island of Hawaiʻi at risk for a major close-call hurricane by the weekend

180 mph Category 5 Hurricane Polo Tuesday afternoon over the eastern Pacific about 200 miles south of Mexico. Credit: CIRA Satellite Library

Hurricane Polo topped the scales as a showstopper Category 5 hurricane over the eastern Pacific about 200 miles south of Mexico Tuesday. The hurricane tore through records, strengthening from a disorganized tropical depression to a Category 5 hurricane in a remarkable 42 hours, the fastest of any system on record in the western hemisphere.

By Tuesday afternoon, NOAA hurricane hunters flying through Polo found its central pressure had bottomed out at a jaw-dropping 892 millibars, catapulting it to the second most intense eastern Pacific hurricane ever recorded, trailing only 2015’s Hurricane Patricia.

Its winds peaked at 180 mph at around the same time Tuesday, tying it with Hurricane Rick in 2009 for the third strongest eastern Pacific hurricane on record by maximum sustained winds (only Patricia in 2015 and Linda in 1997 had higher estimated winds).

Hurricane hunters flying through Polo’s eye at around 8,000 feet above the violent Pacific also recorded temperatures in its eye at flight level of 31.3°C (88.3°F), indicative of an intensely warm core only found in textbook, upper-echelon hurricanes.

In fact, based on thousands of hurricane hunter flights spanning almost 40 years across both Atlantic and Pacific basins, the flight-level temperature reading inside Polo’s eye on Tuesday tied Hurricane Rita’s in 2005 for the warmest on record, surpassing even some of the most intense western Pacific Super Typhoons ever directly observed like Megi in 2010.

Minimum sea level pressure (in millibars on the vertical axis) versus flight-level eye temperature (in degrees Celsius on the horizontal axis) for all hurricane reconnaissance (recon) flights across the North Atlantic, eastern North Pacific, and Western Pacific basins from 1989 to present. Polo ties Hurricane Rita in 2005 for the warmest eye temperature recorded at flight level (around 700 mb or 8,000 to 10,000 feet up) by hurricane hunters. Credit: Derrick Herndon/University of Wisconsin-Madison/CIMSS

It’s hard to fathom reaching out of an airplane at 8,000 feet and finding temperatures as balmy as 88 degrees Fahrenheit. Simply put, the amount of latent heat being released inside the core of Polo from the intense ring of thunderstorms surrounding its eye (the notorious eyewall) was exceptional, a rare show of force from Mother Nature when everything aligns to form one of the most powerful storms on Earth.

Polo plateaus

Polo appeared to have plateaued by Wednesday morning but remained a powerful Category 4 hurricane. Its very slow drift has churned up cooler waters from beneath the ocean surface, which likely contributed to its somewhat degraded satellite appearance by daylight Wednesday.

Fluctuations in its strength are likely over the next day or two before Polo begins a gradual weakening this weekend. Thankfully Polo’s destructive core will stay safely offshore this week, but outer rainbands and winds gusting to above 40 mph will continue to affect parts of southwestern Mexico through early Friday.

Probability of Polo passing to within about 100 miles of a given location based on our global forecast models and their ensembles. Polo’s core will remain south of Mexico over the next few days but it’s unclear whether a weaker Polo could pose a direct threat to parts of the Baja California Peninsula of Mexico next week. Credit: Tomer Burg/polarwx.com

It’s too soon to know if Polo could pose a direct threat to the Baja California Peninsula of northwestern Mexico next week, but it’s something interests in the area should continue to monitor.

Another Hawai’i hurricane threat this weekend?

Tropical Depression Fifteen, which unraveled a week ago over the open eastern Pacific, has found a second wind over the central Pacific about 400 miles south-southeast of the Big Island of Hawaii.

The system re-formed early Wednesday and forecast models show it cranking up in the coming days into a major Category 3 hurricane as it bends north then takes a dogleg left toward the Big Island for the weekend.

The verdict is still out on how close the future hurricane could get to Hawaiʻi, but the initially northward trajectory and sharp left turn are both concerning factors that could make this one of the stronger approaches to the Big Island we’ve observed.

As of their Wednesday morning advisory, the National Hurricane Center was predicting a 115 mph Category 3 hurricane to pass within 50 miles of the Big Island by Saturday evening local time, too close for comfort given the average error of around 100 miles at that forecast time.

Residents and visitors to Hawaii – particularly those on the Big Island – should continue to follow the forecast closely this week.

No major development threats in the Atlantic

The only two areas being tagged by NHC today are far away from the U.S. and neither should amount to much.

The remnants of Tropical Storm Fay have a small chance of redeveloping this week while a disturbance just moving off the coast of Africa could make a run as a short-lived tropical depression or storm as it moves northward toward the Cabo Verde Islands off Africa tomorrow through Saturday. Although it could bring blustery weather and locally heavy rain to the Cabo Verde islands, upper-level conditions will become increasingly hostile to organization beyond the weekend.