The 2017 hurricane season is mostly remembered for Hurricanes Irma and Maria, and the devastation those storms brought to the Caribbean and Florida, especially Puerto Rico. But not if you live in Texas.
Because the storm that kicked that summer's parade of extreme weather was Hurricane Harvey. It developed quickly and then dumped record amounts of rain on Houston — so much that it became the wettest tropical cyclone on record in the United States (about 1,500 mm or 60 inches of rain). It was also tied with 2005's Hurricane Katrina for the costliest tropical cyclone.
It took months to get the city back to normal (though the fact that the Astros won their first-ever World Series later that year gave people in Houston something to rally around!). With the city so recently and terribly flooded, you would think that they would be on permanent extreme flood alert.
And yet just last week, Tropical Storm Imelda arrived and gave the Houston-area three days of around 1,000 mm (40 inches) of rain. To be clear, no one can stop a storm from coming. But people across Twitter and Facebook expressed great surprise that Imelda was so intense.
Looking into weather forecasts in Houston before the storm arrived, it is clear that the storm arrived fast. It was difficult to predict and was only really confirmed as a tropical storm a day or so before.
This happened with Hurricane Harvey, too. At first, it looked like it had almost died in the Gulf of Mexico and wouldn't hit land at all. Then within a day or two, it was a monstrous Category 4 hurricane! But even then, Harvey took many days to finally reach Houston. In this case, Imelda really did take the city by surprise.
In short, not only are hurricane paths tough to predict, but their strengths are, too!
What's in a name? A lot!
But hey, aren't we talking about hurricanes? What is a tropical storm anyways?
The Saffir-Simpson Scale, which measures a storm's wind strength, lists hurricanes from Category 1 (weakest) to 5 (strongest). Just under a Category 1 is a tropical storm. So lower winds, no problem, right? Wrong.
These storms may not have hurricane-sized wind strength, but they're still huge. And winds are only part of the fury of these storms. They can also dump incredible amounts of rain. And that means flooding.
Want proof? Hurricane Harvey changed its strength many times after it made landfall and crawled along the Texas coast. And its rating by the time it stopped over Houston in 2017? That's right: it was a tropical storm.
When all is said and done, this is a reminder that even tropical storms carry a mighty wallop. And it's also something to keep in mind with Tropical Storm Karen near Florida and the Bahamas right now.