Government authorities in war-torn Yemen as well as officials in neighboring Oman are urging people to evacuate coastal areas on Sunday as a very powerful—and extremely rare—cyclone readies to make landfall.

Cyclone Chapala has now been categorized as the second-strongest tropical storm ever recorded in the Arabian Sea, fitting itself into a pattern of unusually strong storms around the globe which meteorologists and the scientific community say are being exacerbated by increasingly warmer air and ocean temperatures.

The UN’s World Meteorological Organization described Chapala as “an extremely severe cyclonic storm” with wind speeds was equivalent to a Category Four hurricane.

In a noon update on Sunday, the Oman Meteorology Department issued warnings of waves reaching heights of nearly 33 feet and wind speeds accelerating to 170kmph as Chapala hit outer islands off the southern coast of Yemen. Oman itself was beginning to feel the brunt of the storm with onshore waves reportedly reaching 23 feet. The OMD was warning of large rainfalls and strong winds in addition to a powerful storm surge.

Given the civil war and severe humanitarian crisis that currently grips Yemen, many worry the storm will be much more devastating for the nation’s people than it might be otherwise. As freelance journalist Charlene Rodrigues,  who covers the region for various outlets, commented on Twitter: “As if Yemen hasn’t had enough. Airstrikes, shelling, suicide bombing, blockades, no water, food, power. Next cyclone!”

As the storm moves ashore, write meteorologists Bob Henson and Jeff Masters at Weather Underground, Chapala will likely “slam into steep mountains near the coast, boosting its potential to dump several years’ worth of rain in just a day or two.” The impacts could be devastating for both urban centers along the coast and communities in the mountains.

According to Al-Jazeera, the track of the storm has moved west from earlier predictions and now appears on “a path towards eastern Yemen’s war-torn sea port of Mukalla and its population of 300,000 people.”

The storm is expected to bring torrential rain, thunderstorms, strong winds and damaging storm surges when it makes landfall on Monday evening.

Mukalla could see up to 500mm of rain from the cyclone – more than seven times its average yearly rainfall of 70mm. Such an amount would cause widespread flooding, and given the rugged terrain, also lead to flash flooding and landslides.

Even before making landfall, meteorologists and experts are saying that Cyclone Chapala is historically and scientifically significant. As Skymet reports:

The last quarter of the year 2015 will be remembered for two extremely fast developing storms; Hurricane Patricia and now Cyclone Chapala. In no time, these two storms intensified rapidly stumping meteorologists across the globe. While Patricia dissipated rather quickly towards the end, Cyclone Chapala continues as a Category 4 storm on Saturday.

Now Hurricane Patricia was the most intense hurricane on record in the western hemisphere, and Chapala is likely to become the strongest storm in the Arabian Sea. Cyclone Chapala recorded 80 knots of intensification in the last 24 hours, which is pretty impressive for a storm running wild in the Arabian Sea. […]

The amount of rainfall Chapala is likely to give over Yemen (and neighboring Oman) is staggering. A narrow stretch bordering Oman, in East Yemen, could see 500mm of rain in just a few days. As per rainfall records available for the region, 500mm would be five years’ worth of rainfall.

Now because this rain will fall on dry and hard surface, it translates into massive flash floods for the region. A few areas in this zone are desert-like, and will be over-run with rushing water, thereby causing potential damage to life and property. Weather experts believe that these rains will be a ‘once in a lifetime’ affair for some people in the region.