Category: Features

Last week’s storm system was mostly about the heavy rain and flooding, as Eric summed up nicely here. But the story that I think was most fascinating, meteorologically, was the hailstorm that hit some parts of the Houston area on Thursday night. The National Weather Service Houston office collected over 20 hail reports from the event, more than half of which were golf ball size hail or larger.

Houston doesn’t often get hail this big over this wide an area. So what happened here? Why did we have so much big hail last Thursday?

Houston doesn’t see a lot of hail

If you look at the map of annual average 1+ inch diameter hail days per year (this from 2003-2012), you’ll notice Houston is mostly on the outside looking in at significant hail reports.

Severe hail reports are most common from Missouri and Kansas into South Dakota. (NOAA)

Why is this the case? For one, thunderstorm updrafts are needed to allow for the water droplets that become hailstones to get above the freezing level. Houston is a warm place, and that freezing level is often too high and the storms not powerful enough to carry those droplets high enough for large hail to form. Our lower freezing levels occur in winter and spring, making hail more likely then. In fact, of the 62 hail reports of 2″ in diameter or larger in NOAA’s storm events database since 1950 in Harris County and adjacent counties, only 3 of those reports have occurred outside of January through May. The average hail maxima is also where it is because they simply get more powerful, supercell thunderstorms with violent updrafts in the Plains.

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We recommend: Weather books for weather enthusiasts

Posted by Matt Lanza at 10:00 AM

In the wake of Harvey, it’s been interesting and fun to see so many people seeking out ways to learn more about weather, flooding, hurricanes, and more. Knowledge is power, and both Eric and I want to see our community more knowledgeable about weather risks. We will attempt to give you a few book suggestions here. This list isn’t comprehensive by any means. It’s just a listing of books we’ve read about weather that we think our readers may find interesting, and hopefully it’s a group of books some of you can learn something new from! All links point to Amazon for simplicity, but I’m sure you can find some of these on local shelves or order them through local bookshops.

“Isaac’s Storm,” by Erik Larson – No, we couldn’t make a weather book list in Southeast Texas without including this title. “Isaac’s Storm” tells the story of the 1900 Galveston Hurricane and Isaac Cline, the weather observer at the time, and what he was able to do (and not do) through the storm. You won’t get a full meteorology education here, but this is a must-read for anyone interested in Houston, Galveston, or hurricanes.

“Hurricane Watch,” by Jack Williams & Bob Sheets – Jack Williams is one of the best weather journalists out there, and Dr. Sheets is a former director of the National Hurricane Center. He is also one of my childhood meteorology “heroes” who inspired me to be a strong weather communicator. This book walks you through the history of hurricane observation and prediction, going way back in time and bringing you up through Hurricane Andrew in 1992. It includes a look at the history of the Hurricane Hunters, why we can’t control hurricanes, and closes with a look at the future (as written in the early 2000s). This is a great introduction to hurricanes, their prediction, and the history behind that.

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