Typhoon Haiyan: Is this a Cat 6 Hypercane?
November 8, 2013
It’s too soon to tell, it will be weeks till the dust settles and things dry out. But Typhoon Haiyan is a monster. Worst ever?
More as it comes in. For now there’s this.
By at least one measurement, it appears that Super Typhoon Haiyan, which just slammed into the Philippine island of Samar, may be the strongest storm reliably recorded on Earth. Additional measurements and analysis will surely be necessary to confirm this, but for now, here’s what we know:
The U.S. Navy’s Joint Typhoon Warning Center, which tracks typhoons and Super Typhoons—the most powerful storms on the planet—estimated Haiyan’s maximum 1-minute sustained winds at 170 knots, which translates into about 195 miles per hour.
According to meteorologist Jeff Masters, a number of Pacific storms prior to 1969 were measured with wind speeds equal to or above 170 knots, but these estimates are now considered unreliable. Since 1969, the three strongest storms on record by wind speed all had winds of 165 knots, or 190 miles per hour: 1979’s Super Typhoon Tip, 1969’s Atlantic Hurricane Camille, and 1980’s Atlantic Hurricane Allen. Haiyan just passed all three by this metric, though Masters notes that there is less confidence in Haiyan’s true intensity, since Tip, Camille, and Allen were all investigated by hurricane hunter aircraft. Haiyan’s intensity has only been estimated based on satellite images (you can read more about how these satellite measurements are done, and why Haiyan presented such a stunning satellite image, in this great New Republic article by Nate Cohn).
There are some additional caveats here: Wind speeds are only one way of determining a storm’s intensity. Another is measuring its minimum central pressure, and here Tip still reigns supreme, with a minimum central pressure of 870 millibars.
Most disturbing of all is another record: At landfall, Haiyan was more intense than any other landfalling storm.
Is it possible that Haiyan was a “Category 6” hurricane? Officially, the Saffir-Simpson hurricane scale defines the category 5 range (the highest category) as beginning at 137 knots. But once you’re 33 knots above that, as Haiyan was, perhaps the scale has been superseded. After all, the entire Category 2 range only spans 12 knots.
A senior meteorologist writes:
Sustained winds of 195 with gusts to 230.To put this into perspective an EF-5 tornado has winds over 200 mph. Yolanda is equivalent to an EF-5 tornado, one that’s 40-50 miles in diameter, lasting 2-3 hours. Not sure I’ve ever seen that before…