In short
- Hurricane Polo was downgraded from category 5 to category 4 on Wednesday morning, the US National Hurricane Center said.
- A NOAA Hurricane Hunter aircraft flew into Polo on Tuesday and recorded sustained wind speeds near 180 mph (285 km/h), with stronger gusts.
- Rainfall totals of up to 6in (15cm) are forecast for parts of south-western Mexico, with 8in possible in some areas.
- Mexico’s President Claudia Sheinbaum named Jalisco, Colima and Michoacán as states at risk and said Polo was not expected to make direct landfall.
- Daily sea surface temperatures in a key central-eastern Pacific region were 3.05C above average on 19 September, above the 3.02C record set during the 2015 El Niño.
Hurricane Polo was downgraded from category 5 to category 4 on Wednesday morning as it drifted slowly off Mexico’s south-western Pacific coast, the US National Hurricane Center said. The storm is not expected to make landfall but is forecast to bring torrential rain and dangerous surf, and a tropical storm warning remains in effect for parts of south-western Mexico.
Where is Hurricane Polo heading?
Forecasters expect Polo to continue drifting north-west off Mexico’s Pacific coast. Mexico’s President Claudia Sheinbaum said on Tuesday that the storm was not projected to hit land directly: “So far, the information we have is that (Polo) will not make a direct landfall on the coast.” Sheinbaum urged residents along the Pacific coast to stay vigilant and named the states of Jalisco, Colima and Michoacán as being at risk. The National Hurricane Center said Polo’s intensity was expected to fluctuate over the next few days.
How strong are Hurricane Polo’s winds?
A Hurricane Hunter aircraft operated by the US National Oceanic and Atmospheric Administration (NOAA) flew into Polo on Tuesday and recorded sustained wind speeds near 180 mph (285 km/h), with stronger gusts. That made Polo a category 5 storm, the highest level on the scale, before it was downgraded to category 4 on Wednesday morning. NOAA described the environment around the storm as “very conducive”, because of extremely warm ocean water, and said Polo could still strengthen.
Which parts of Mexico are under warnings?
A tropical storm warning remains in effect for portions of south-western Mexico, and a tropical storm watch is in effect west of Playa Perula, according to the National Hurricane Center. People under the warning should expect conditions to develop on Wednesday, the centre said, while those in the watch area can expect them by Thursday. Rainfall totals of up to 6in (15cm) are forecast, with 8in possible in some areas, and forecasters warned that Polo “may produce life-threatening flooding and mudslides, especially in areas of steep terrain”. Residents were also warned of large ocean swells and life-threatening surf conditions over the coming days.
Why is Hurricane Polo so strong?
Polo is being fuelled by extremely warm waters caused by the El Niño climate phenomenon. Scientists monitoring ocean temperatures say the current El Niño is now the strongest on record: daily sea surface temperatures in a key region of the central-eastern Pacific were 3.05C above average on 19 September, exceeding the previous record of 3.02C set during the very strong El Niño of 2015. Some longer-term measures of El Niño have not yet reached record levels, but that is likely to change, with the peak not expected until later this year. El Niño is a naturally occurring pattern that happens about every two to seven years and tends to last around a year. Warmer ocean water allows storms to pick up more energy, which can lead to higher wind speeds.
How active has the Pacific hurricane season been?
So far this season the Pacific has seen 15 storms, all in early September. Polo is the strongest of a batch of three storms currently swirling between Hawaii and the North American mainland.
Frequently asked questions
Will Hurricane Polo make landfall in Mexico?
Mexico’s President Claudia Sheinbaum said on Tuesday that the available information indicated Polo would not make a direct landfall on the coast. A tropical storm warning nonetheless remains in effect for portions of south-western Mexico.
How strong are Hurricane Polo’s winds?
A NOAA Hurricane Hunter aircraft recorded sustained wind speeds near 180 mph (285 km/h), with stronger gusts, when it flew into the storm on Tuesday. Polo was downgraded from category 5 to category 4 on Wednesday morning.
Why is Hurricane Polo so powerful?
The storm is being fuelled by extremely warm Pacific waters linked to the El Niño climate phenomenon, which scientists say is currently the strongest on record based on daily sea surface temperatures.
Which Mexican states are at risk from Hurricane Polo?
President Claudia Sheinbaum highlighted Jalisco, Colima and Michoacán as being at risk. The US National Hurricane Center has a tropical storm warning in effect for portions of south-western Mexico and a tropical storm watch west of Playa Perula.
With reporting from BBC News.
Stock image, not from the events described. Sea Beach — Sergei Gussev / Wikimedia Commons (CC0 1.0)
