Storm surge from hurricanes is deadly. New computer models can better forecast it
MARY LOUISE KELLY, HOST:
The Atlantic hurricane season begins tomorrow. And this year, the National Hurricane Center is making a big upgrade to its forecasts, especially when it comes to storm surge. That's the wall of ocean water that hurricanes push onto the land. It can be deadly, and climate change is making powerful storms with powerful storm surge more likely. NPR's Rebecca Hersher reports that forecasters are hoping to save lives.
REBECCA HERSHER, BYLINE: It's hard to overstate how dangerous storm surge can be. The water is so powerful, it can tear entire homes from their foundations. It's the reason for most evacuation orders, but people don't always have enough time to evacuate. Cody Fritz leads the storm surge unit at the National Hurricane Center in Miami.
CODY FRITZ: In years prior, we might have been able to predict those extreme events about two days in advance.
HERSHER: That is not very long. Imagine needing to pack your things, board up your windows, find a place to go - all in 48 hours or less.
FRITZ: The real improvement in this model is to kind of increase that lead time beyond two days, to almost, say, three days.
HERSHER: A whole extra day to evacuate.
FRITZ: This is quite a big upgrade.
HERSHER: In addition to giving more lead time, forecasters will also have better information about how far inland the water will go. That's because they've added details about plants - trees and wetlands and other vegetation along the coast.
FRITZ: And that helps to slow the water down and reduce how far inland it can actually penetrate.
HERSHER: So with plant information in the mix, the storm surge forecasts will be more accurate. But arguably, the largest upgrade is about which Americans get storm surge forecasts at all. Up until now, there was virtually no real-time storm surge forecasting for the territories of Puerto Rico and the U.S. Virgin Islands, even though they're extremely threatened by hurricanes. Entire neighborhoods have been swept away.
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UNIDENTIFIED REPORTER: Hurricane Irma plowing through the Caribbean with 185 mile-per-hour winds, leaving a wake of destruction in her path.
HERSHER: A few weeks after Irma, Hurricane Maria brought up to 10 feet of storm surge to Puerto Rico. All that moving water also causes dangerous pollution. Ingrid Padilla studies water contamination at the University of Puerto Rico. She says there are dangerous chemicals, heavy metals and other pollution hiding in plain sight in coastal areas - in landfills, factories, farms.
INGRID PADILLA: When you have flooding, those contaminants could be picked up by the water.
HERSHER: The pollution can get into the water supply. Bacteria in drinking water can make people sick.
PADILLA: You start seeing people having GI problems very fast.
HERSHER: That happened after Hurricane Maria. Many people in Puerto Rico were cut off from reliable drinking water for weeks, if not months, and people got sick or even died of illnesses that were caused or exacerbated by contamination. Padilla says protecting people from pollution goes way beyond what a hurricane forecast can accomplish on its own, but better storm surge forecasts could help keep people safer.
PADILLA: My sense is that it will definitely help on the spot to make very quick decisions.
HERSHER: Like evacuation orders or warning residents when drinking water is contaminated. So why didn't Puerto Rico and the U.S. Virgin Islands get these forecasts earlier? Fritz from the National Hurricane Center says predicting how water will interact with the coastline of a small island requires more complex computer models than for the mainland.
FRITZ: They can take quite a long time to run and many computers to kind of simulate that event.
HERSHER: But when a hurricane is headed for land, you need to be able to update and warn people every few hours.
FRITZ: We don't have a lot of time.
HERSHER: Now, they've figured out how to run the models in an hour or less. It took years and a team of about half a dozen people. Hurricane season starts tomorrow and runs through the end of November.
Rebecca Hersher, NPR News. Transcript provided by NPR, Copyright NPR.