Michael’s potential upgrade to Cat 5 another sign of its destructive power
In the hyper data world of hurricane forecasting, where history is written in millibars and miles per hour, the National Hurricane Center’s 168year record of Atlantic storms stands as an invaluable index to meteorologists, the insurance industry, government planning departments and, of course, weather geeks.
What’s less known: It gets tweaked a lot. Since 2008, hurricane researchers have added new storms to the record almost every year, uncovering more information in old ship and weather records that more often than not depict mightier storms. As recently as 2011, they discovered two new hurricanes. Altogether, they have identified 82 overlooked tropical storms and three hurricanes swirling in the Atlantic since they began revising old records in the mid1990s. Dozens more hurricanes have been reclassified to higher and lower categories.
Hurricane Michael, which hit the Florida Panhandle as a Category 4 storm, now enters that record, and in the coming months will get a hard second look. So it’s natural to wonder: Will Michael, too, get revised?
If it gets upgraded to a Category 5, it would be a very rare event. Only three Category 5 U.S. landfalls have ever been recorded. Two of those, the 1935 Labor Day storm that hit the Keys and Hurricane Andrew in 1992, were the result of revisions.
“You can’t say for sure, but the odds are high that it would have been a Cat 5 if it had had three more hours over ocean water,” said Colorado State University meteorologist Phil Klotzbach. “It was still on a strengthening trend.”
At landfall, the storm’s pressure reading was the thirdlowest on record for a U.S. hurricane, a hint that winds measured just 2 miles per hour shy of a Category 5 threshold might turn out to have been stronger.
In the postanalysis, forecasters will broaden their focus to look around the storm’s path for data about wind, rainfall, storm surge and damage estimates, said hurricane center spokesman Dennis Feltgen. No longer under the gun for a storm that appeared suddenly and rapidly intensified three times as it took aim at the Panhandle, they will be able to take a less stressful look at data collected by hurricane hunter planes and surface wind readings, measured with microwaves, that often require a more nuanced reading.
“It’s not like they necessarily find new sources of data,” said hurricane researcher Brian McNoldy at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. He suspects Michael will be reclassified as a Category 5 hurricane. “You have the benefit of hindsight and you have more time. You’re not under the constraint of an operational framework,” he said.
The report will be ready early next year. So what if Michael gets reclassified? It won’t make a difference to places such as Mexico Beach and rural Gadsden County, where the hurricane’s pounding winds flattened entire blocks. At least 25 deaths have so far been blamed on the storm.
But for meteorologists building models and making seasonal forecasts, and building officials looking at the toll caused by weaker building codes in the Panhandle, the information is vital. It’s also important for scientists tracking global warming.
“There are so many critical questions the hurricane database can answer,” said Chris Landsea, chief of the hurricane center’s Tropical Analysis and Forecast Branch.