Earth News Journal 39: The Might of Haiyan

As severe weather occurrences increase around the globe, due in part to global climate changes, the accuracy upon which forecasters rely for broadcasting major storms may need to increase, as well.

Supertyphoon Haiyan, which rocked the coasts of the Philippines in mid November 2013, is arguably one of the strongest tropical cyclones to ever strike land, though the “exact strength [of the storm] was a matter of dispute.”

For nearly the past four decades, weather experts have been utilizing what is known as the Dvorak technique, named after scientist Vernon Dvorak, to determine tropical storm intensity. Temperatures from the hurricane’s or typhoon’s sea surface and cloud cover are measured by “sensing the infrared radiation emitted from them.”

James Franklin, chief of the hurricane specialist unit at the National Hurricane Center in Miami, Florida, has described the technique as “An inkblot test for hurricanes.” In addition, the analysis also includes the temperature of the cloud tops, which is “an indication of their depth, and the width, and temperature of the eye,” Franklin added.

Based on certain categories of wind speeds and air pressures derived from the Dvorak technique, the tropical storm is given a rating. Unfortunately, the data from these ratings don’t always yield the same result – “two analysts looking at the same image can come up with different ratings, especially for weaker storms.”

Different units of wind speed measurements in varying countries can also lead to expert confusion, thus the true value of the storm’s intensity is lost to miscommunication, as opposed to miscalculation. Nonetheless, the tools themselves pose several disadvantages to research analysts, as well, for the proper technology may not be present in the particular region of the storm.

The United States has systematic and highly-trained weather programs across the nation, but “few [other] countries make direct measurement by flying planes into these kinds of [severe] storms.”

“Nobody out there does routine inner-core reconnaissance in the way we do it here,” Franklin remarked.

The most accurate measurements are taken with airplanes, according to American weather analysts, especially before the storm hits land. But even these wind speeds are “only estimates” – some of the readings can have a 25 mph or more variation. Forecasting agencies suspect the disputed data of Supertyphoon Haiyan (195 miles per hour winds vs. 150 miles per hour winds) came as a result of differing technologies between the Philippines and the United States.

Forecasts prior to the storm itself may have also been misleading. Nevertheless, John A. Kaff of the National Oceanic and Atmospheric Administration’s Center for Satellite Applications and Research concludes, “From the technique’s standpoint, this was about as good as you can get.”


I remember when Supertyphoon Haiyan hit – I was backstage at a Peter Pan rehearsal, when suddenly my Twitter feed was ablaze with reports from the Philippines. Hundreds, then thousands, then millions of helpless citizens were reported affected by the superior might of Haiyan, and I could sense the despair of the island people – hundreds of thousands of miles away in suburban America. If the predications are accurate – if we are projected to have an increase in severe tropical storms because of global climate changes – then I say it’s vitally important to completely standardize climate-predicting technologies. From the sound of it, the Dvorak technique appears to provide nations with fairly accurate readings of storm intensities, albeit some slight discrepancies. Nonetheless, by enhancing this technique and the technologies that accompany such measurements, we can further unite the global network of knowledge by informing countries with accurate, precise, and confirmed forecasts. Perhaps these extremely-accurate predications can aid the affected countries and provide appropriate protection strategies. The more we advance our understanding of the global forces of nature, the more we can protect a nation’s people from utter disaster and ruin. 

Fountain, Henry. “Measuring the Might of Haiyan.” The New York Times. N.p., 18 Nov. 2013. Web. 03 Apr. 2014.

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