Yemen is expected to see its first hurricane on record early this week, as Tropical Cyclone Chapala hits just southwest of the city of Al Mukallah on Monday evening or Tuesday morning, eastern time (that's between early Tuesday morning and early afternoon, local time). Since records began in the region in 1945, no hurricane-strength tropical cyclone has hit the desert country; hurricanes are referred to as tropical cyclones in this region, just as they are known as typhoons in the western Pacific.

The storm may bring catastrophic amounts of rain — at least a decade's worth of rain over the course of just a day or two in populated areas of war-torn Yemen, a country currently involved in a complicated civil war that involves regional powers, including Saudi Arabia.

The war will severely limit the ability of Yemen's government to respond to any flooding and other storm damage with aid and other assistance, placing an even greater burden on already-stretched international aid groups and the United Nations.

Tropical Cyclone Chapala seen on satellite imagery nearing Yemen on Nov. 2, 2015. Image: NOAA

The coastal city of Al Mukallah, where about 300,000 live, is the capital of the Hadramaut region. Mukallah is Yemen's fifth-largest city, and could be vulnerable to storm surge flooding as well as mudslides from heavy rain falling on nearby mountains. From a point southwest of Mukallah, the storm is expected to weaken while pouring rain onto the desert soil of interior Yemen, followed by complete dissipation over Saudi Arabia in under 24 hours after landfall.

The storm is forecast to make landfall as the equivalent of a Category 1 or 2 hurricane, after reaching Category 4 intensity with 155 mph sustained winds several days ago. This made Cyclone Chapala the second most intense storm on record in the Arabian Sea and the strongest storm on record so far south in the Arabian Sea.

While the storm could bring wind damage to areas along the southern Yemeni coast, as well as storm surge-related flooding, it is the rainfall that presents the greatest danger. The average annual rainfall along the coast of southern Yemen is just 2 inches, or 50 millimeters, according to Weather.com, meaning that the storm's expected total of up to 20 inches, or 500 millimeters, could lead to record flooding.

This means that the people of this region are facing a situation they have never experienced in their lifetime, which has implications for how thoroughly they may prepare for the storm.

The rainfall from #Chapala is far beyond anything ever witnessed in this arid area which is not used to cyclones https://t.co/OwIkc4jmRB — WMO | OMM (@WMOnews) November 2, 2015

The United Nations and foreign aid groups are already assisting the Yemeni people with food, water and medical care related to the war, with the storm carrying the potential to increase the country's assistance needs.

Mountain ranges in southern Yemen will wring out more of the storm's moisture, maximizing rainfall totals there, and potentially sending rivers of mud, debris and water flowing to lower elevations.

Unlike landfalling storms in developed countries such as the U.S. or Japan, Yemen is not a place that has a robust meteorology infrastructure. The civil conflict in recent years has weakened the central government, with parts of the country simply beyond its control, and the nation does not have a sizable network of weather observing sites. In fact, according to Weather.com, Yemen has just eight official weather observation sites, six of which sent no data at all during the month of October.

Why this storm is such an outlier

The storm has taken advantage of all-time record warm water temperatures in the Arabian Sea, which has been caused by a mixture of long-term global warming, a natural climate cyclone known as the Indian Ocean Dipole and the influence of El Niño. The Arabian Sea typically sees about one or two tropical cyclones per year, but rarely do they reach Category 3, 4 or 5 intensity — and rarer still do they eventually make landfall in Yemen.

A recent study showed that global warming may increase the chances of intense tropical cyclones in parts of the Arabian Sea and other areas that don't typically see them today, including Dubai.

Surface average temperature anomalies showing record warm ocean temperatures where Cyclone Chapala formed (blue arrow).

Typically, tropical cyclones dissipate before hitting that country, after ingesting a gulp of hot, dry desert air that chokes off their thunderstorm activity. In addition, ocean temperatures tend to cool closer to the coast, which also helps weaken such storms.

These two factors are helping to weaken Cyclone Chapala as it approaches the Yemeni coast, but it is not likely to dissipate entirely before it hits land, based on forecasts from the Indian Meteorological Department and Joint Typhoon Warning Center.

Cyclone #Chapala rapidly intensifying in the Arabian Sea, seen from the Suomi NPP satellite https://t.co/UgfSLkYGWA pic.twitter.com/QNv1NNehNs — NOAA Satellites (@NOAASatellites) October 30, 2015

There are records of significant storms close to hurricane intensity making landfall in Yemen in the middle of the 20th century, but there is no official record of one this intense dating back to 1945 at least, according to a National Oceanic and Atmospheric Administration database. It's quite possible, however, that a storm of Chapala's intensity, or perhaps a bit weaker, has hit Yemen or western Oman in the past, but went unnoticed due to the sparse population and lack of satellite observing system.

Even weak tropical cyclones have a record of causing significant damage in Yemen, however, largely from the combined effects of the storm and political, social and environmental stress already present in the country.

For example, in October 2008, a tropical depression caused an estimated $1.6 billion in damage in losses in Yemen, mainly from flooding. These losses amounted to 6% of the country's GDP, according to a World Bank report.