Just something to ponder, from Space City Weather.
First of all, if you can remember all the way back to Saturday, I presented three different scenarios for Nicholas’ track and eventual flooding in Houston. The first of these was the “Coast Hugger,” in which the storm remained close to the Gulf, brought 2 to 4 inches of rain to Houston and higher amounts along the coast, while keeping the heaviest rains offshore. This is largely what happened, with Nicholas remaining very close to the coast even after moving inland. If we look at satellite-derived precipitation totals for the last three days, the heaviest swath of 10-20 inches of rainfall came offshore.
A track even 40 or 50 miles further inland would have set up those heaviest rains directly across the Houston metro area, and created a much more serious flood situation. Hopefully this offers you some insight into the challenge of predicting these kinds of rain events. It was a very close call, a matter of miles, between significant inland rainfall flooding in Houston, and relatively clean bayous this morning.
The second factor is wind. Nicholas turned out to be a fairly nasty storm in terms of wind gusts, and pushed a larger storm surge—as high as 6.1 feet into Clear Lake—than predicted. This is a reminder of the power of a hurricane, even one that was “only” a minimal Category 1 storm. The truth is that the track of the storm was very nearly a worst-case one for Houston in terms of winds and putting a maximum storm surge across Galveston Island and into Galveston Bay.
It is September 14, the absolute peak of hurricane season in the Atlantic, and a time when sea surface temperatures in the Gulf of Mexico are at their warmest of the year. So this morning I’m thinking about what would have happened if we had not had some wind shear over the western Gulf of Mexico yesterday, or if Nicholas had been able to consolidate a more well defined and consistent center of circulation. It would have been much, much worse for all of us had a significantly stronger hurricane made landfall last night. So while we pick up the pieces this morning, realize Nicholas could have been much more of a terror.
Not the first time this year that we averted a disaster by dumb luck. We’re four years out from Harvey, 13 years out from Ike, and we’ve had plenty of non-hurricane catastrophic floods in between, so it’s not like we’ve been living a charmed life here in Houston. Lots of people here have been hit very hard, and there’s a whole lot of talk about the trauma and stress that so many folks have experienced and still experience. This is life under climate change. There are things we can do to keep it from getting worse, and there are things we can do to make it better for those who have had the hardest time. But we can’t wish it away or ignore it, and we absolutely can’t deny it. It’s up to all of us.