Hurricane season has come: Here are some questions and answers

Hurricane season officially begins later this week, but as we’ve seen with Subtropical Storm Alberto, Mother Nature doesn’t care overly much about arbitrary dates. Nevertheless, it is the time of year to begin thinking about the tropics, and so we’re going to help you get ready with some questions and answers.

Why does hurricane season occur now?

The easy answer is “warmer water,” and it is true that sea surface temperatures above 80 degrees Fahrenheit are generally needed for tropical storms to form, and strengthen into hurricanes. However, seas in the tropics are generally warmest in October, when hurricane season often begins to wind down. There is another factor, wind shear, that is critical. When winds are rough, and blowing as cross directions at different altitudes, storms simply cannot form. Typically, tropical storms will thrive only when wind shear values near the center are below 20 knots. The following graphic, from FEMA’s Michael Lowry, shows why the hurricane season lasts from June through November, but typically peaks during early September.

(Michael Lowry/FEMA)

Help! I’ve seen a really scary forecast on Facebook

Already this season we’ve seen some hyperbolic forecasts on Facebook. In March, a post forecasting doom and gloom for the 2018 Atlantic season went viral, and more recently a post showing a major hurricane hitting Texas in June got passed around. Such “social mediarology” plays on the fears of people, and therefore tends to get shared widely. If you’ll promise to not fall for these kinds of fear-mongering posts, we’ll make a pledge to you: If we believe there is a credible threat to Houston, we will report that immediately. And if we haven’t written about it, the post you’ve seen on Facebook is probably garbage.

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Texas will sit under a big ol’ high pressure ridge this week

Memorial Day weekend has come and gone, Houston’s basketball season has unfortunately ended, and the first named storm has already graced the tropics—I guess we must acknowledge that summer has really and truly come to Houston. This means two things for the upper Texas coast: high pressure, and when there’s not high pressure it means the region is open to tropical moisture. To that end, with the onset of hurricane season, we’ll have some additional content this week. Later today, in fact, I’ll answer some commonly asked questions about Houston and hurricanes. Later this week Matt will talk about how Hurricane Harvey changed the way local meteorologists were challenged and changed by the storm.

Texas is going to sit under a big, fat ridge of high pressure this week. (Weather Bell)

Tuesday

For now, high pressure ridging will remain dominant. There really is not a whole lot to say as we settle into a familiar pattern of warm, sunny days, with high temperatures in the low- to mid-90s, and warm nights in the mid- to upper-70s.

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Storms possible near Houston again on Sunday

Yesterday’s thunderstorm activity probably came as a bit of a surprise to many of us, not so much because they happened but because of how potent they were. We saw a few reports of hail and wind damage around the region. And some incredible sky pictures.

https://twitter.com/JCB_511/status/1000548824383881216

Our Friday forecast suggested the most activity would be east of US-59 on Saturday, and it was, but I’d be lying if I told you I was expecting the potency that it came with. So why did it happen?

A confluence of factors led to a busy Saturday evening. Storms early in the day in western Louisiana and eastern Texas likely produced some boundaries in the atmosphere, and with winds directing weather in the less common northeast to southwest direction, they ended up moving our way. We probably saw cold air aloft, necessary to help regenerate storms as they moved across southeast Texas. We had sea breeze interaction with some of those boundaries also. There was decent jet stream and upper level support in the northeast flow that helped add extra support. Then, it also hit 94° at IAH, so you had plenty of instability. All these factors came together just right, and we ended up exceeding most people’s expectations, including my own.

So that begs the question: Will we do it again today?

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Alberto kicks off 2018 hurricane season; no concerns for Texas

Not long after our morning update on Friday, the National Hurricane went full steam ahead and declared the disturbance near the Yucatan Peninsula to be (Sub)tropical Storm Alberto (more on that in a moment). For us in Houston, this is of *no* concern. We remain with a hot and mostly dry forecast. But if you have friends and family east of here or know folks visiting there for the holiday weekend, we wanted to provide a quick update.

Now

Alberto has maximum sustained winds of 40 mph, making it a lower-end tropical storm. Looking at a satellite loop, you can see Alberto is far from the most aesthetically pleasing tropical system we’ve ever seen.

Subtropical Storm Alberto late Saturday morning has a center in there somewhere, well displaced from the majority of the thunderstorm activity. (College of DuPage)

The center of Alberto is sort of broad in nature and located just off the western tip of Cuba. It may hopscotch its way along over the next 12-24 hours, reforming at times in different places in the southeast Gulf.

Forecast track & intensity

Over the next 24-36 hours, the environment over Alberto is expected to become more hospitable for a tropical storm. Thus, Alberto should strengthen a bit on its trek north. The current forecast from the National Hurricane Center takes Alberto north to between about Gulfport, MS and Panama City Beach, FL, with a possible landfall by Monday night or early Tuesday.

The National Hurricane Center forecast has Alberto approaching the central or eastern Gulf Coast by Monday night as a moderate to strong tropical storm. (NOAA/NHC)

While the NHC track is fine, some forecast modeling shows Alberto taking a more erratic path as it approaches the eastern Gulf, possibly shifting a couple hundred miles east or west. Thus, tropical storm watches cover a pretty broad chunk of the coast, between far eastern Louisiana and the New Orleans area to just south of Tallahassee on the Florida Panhandle. The Tampa area is also under a watch. Tropical storm watches mean tropical storm conditions are possible within the next 48 hours.

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