On the brink of Category 5 status, Cyclone Kyarr is a monster. The Indian Ocean beast — dubbed a top-tier “super cyclonic storm” by the India Meteorological Department — is the first storm of such intensity to rage in the Arabian Sea in 12 years.
While Kyarr will remain largely out to sea, it’s “very likely to maintain” intensity through Monday night before beginning to curve west-southwest. It has also helped propel 2019 into the top spot for most active North Indian cyclone season on record.
The storm now
Now, Kyarr has maximum one-minute sustained winds of 150 mph, with gusts approaching 185 mph in the storm’s eyewall, the zone of most extreme winds. That puts it 7 mph below the threshold of equivalent Category 5 status.
Satellite imagery captured its stunning symmetry Monday morning, Kyarr exhibiting its well-structured banding and translucent, mistily veiled eye. Crystal-clear skies can be seen to the northwest of the storm, where sinking outflow air suppresses any cloud growth. Outflow channels are also visible in the banded, wispy tendrils of cloud protruding like fingers out of the storm’s southern tier.
It will probably begin weakening within the next 24 hours beginning Tuesday morning, expending its massive energy as it ticks down to tropical storm or Category 1 strength over the weekend.
Where it’s going
Forecast agencies began tracking the incipient cyclone as early as Oct. 20, when a weak area of low pressure began to materialize over the southeast Arabian Sea. On Oct. 2, it organized into a tropical storm; between Oct. 25 and 26, Kyarr lurched in strength, rapidly intensifying into a Category 3-equivalent storm. Studies have documented an increase in these rapid intensification events likely tied to climate change.
On the forecast track, Kyarr’s destructive wind field will evade land for the time being, though waves over the open ocean could top 50 or 60 feet.
The system will pass north of Yemen-owned Socotra before meandering into the Gulf of Aden. Its then rapidly decaying remnants will thread the needle between Somalia and Yemen but could throw a bit of moisture to the ordinarily water-starved landscape to the north.
If any rain does occur there from this oddly tracking cyclone, it would be highly unusual: Bosaso, Somalia, and Al Mukalla, Yemen, average less than 1 and 2 inches of rain annually per year, respectively.
Coastal Oman could also see a few showers. Otherwise, Kyarr by then should have lost most of its strength, its circulation largely dissipating as it churns westward. Wind is not expected to be a threat on land.
It has been a landmark year for hurricanes in the North Indian Ocean. In fact, it has been the Indian Ocean’s most energetic cyclone season on record, with reliable, satellite-based bookkeeping dating back to 1972.
Thus far, 2019 Accumulated Cyclone Energy, or “ACE,” has hit 53.9 units. ACE is a measure of how much kinetic energy a cyclone is dishing out through its winds. Consider that the average year-to-date ACE for the North Indian Ocean is no more than 10 units. 2019 has exceeded that benchmark by a landslide; the previous seasonal record was 46.1 ACE units in 2007.
Large inter-annual variability is expected from year to year, with a “normal” season very abnormal. Kyarr is the North Indian Ocean’s seventh named storm this season, marking the first time more than half a dozen had spun up in a single season since 1998.
2019 could also claim one more top spot: the most “major hurricane days” in a given season.
Though hurricanes are called “cyclones” in the Indian Ocean (and “typhoons” in the North Pacific), a figure called “major hurricane days” tracks the number of days for which one major hurricane-equivalent cyclone roams the North Indian Ocean each season. If two major hurricanes do so simultaneously, each day they both exist would go down as two major hurricane days.
The record — 5.25 days, achieved in 2007 and 1999 — may come close to falling. As of Monday morning Eastern time, the 2019 tally was up to 4.5 major hurricane days, 18 hours short of the record, with Kyarr forecast to remain at major hurricane status through at least Tuesday morning.
Kyarr also set the record for the lowest barometric pressure ever observed in the Arabian Sea. Its 915 millibar sea-level air pressure is what you would expect in a “typical” atmosphere if you climbed more than a half mile high. That “deficit” of air draws air inward like a vacuum, fueling the system’s strong spiral winds.
The Indian Ocean Dipole
The banner year for Indian Ocean storms may have gotten a little help from the Indian Ocean Dipole (IOD), a large overturning circulation in the tropical atmosphere over the Indian Ocean.
When the feature is in its positive phase, anomalously warm water pools in the Arabian Sea and west North Indian Ocean, which may help fuel more intense storms. Cooler sea surface temperatures exist farther east, over Australia and the Maritime Continent. This fosters broad rising motion to the west, with subsidence — or sinking — to the east. That rising motion enhances convection, shower and thunderstorm activity, with the relatively weak upper-level winds allowing that convective activity to more easily aggregate into a tropical disturbance.
Recently, the Indian Ocean Dipole’s positive amplitude has been at near-record strength. Western waters have been baking, helping spur an active monsoon season across India, as well. Meanwhile, the scales have tipped farther east in Australia, where scant rainfall heralds prolonged drought that has been parching the continent.
The Australian Bureau of Meteorology expects the Dipole strength to grow even more before breaking some in the next one to two months.
Meanwhile, another tropical wave south of Sri Lanka may develop into a tropical cyclone by Saturday.