Editor’s note: Stephen is a life-long Houstonian and avid weather-geek. He grew up fascinated with the wild Houston weather and loves writing about the processes that create it and its impacts on the area. You can find him on twitter @stephenuzick He will be providing occasional weather coverage for the site.
By STEPHEN UZICK
Wednesday’s storms were fun, right? Well guess what, we’ve won a bonus round. Get out and enjoy the weekend tonight and Saturday because Sunday is shaping to look pretty ugly. Sports-wise there is some good stuff going on with the Shell Houston Open, the Rockets playing the Warriors, The Final Four, and Opening Day for some MLB teams (not the Astros). Weather-wise, tonight and Saturday will be near damn near perfect to claim an outdoor spot at your favorite eating or drinking establishment and soak in some of the above mentioned sports. Sunday on the other hand may not be so “funday” and likely will require a bit more situational and weather awareness.
I will leave the true detailed forecasting to the paid professionals, but the atmospheric set-up is such that I think it is worthwhile to highlight some of the potential risks.
As of this morning Southeast Texas is in an area the Storm Prediction Center (the severe weather focused arm of the National Weather Service) has highlighted for an “Enhanced Risk” of severe storms on Sunday. The Storm Prediction Center issues outlooks for severe weather and assigns categorical risks to areas where storms may occur. Here is a chart from the Storm Prediction Center detailing the risk categories.
Moderate and High Risk areas are only issued the day of the event, are fairly rare (the nation only sees a High Risk areas designated a very small handful of times each year), so if our area gets upgraded to a Moderate Risk on Sunday we really need to pay attention.
DIFFERENT FROM THE STORMS ON WEDNESDAY
Sunday’s weather may have some similarities to what we saw on this past Wednesday, however there will be some important differences. The storms we saw on Wednesday were more consistent with the type of severe weather we usually see – namely a solid line of storms, also known as a squall line, with embedded small hail, heavy rain, strong winds, and a few relatively weak tornadoes. While a squall line may form and move through at some point on Sunday afternoon or evening, the potential exists for supercell thunderstorms to develop prior to that making Sunday’s threat a bit different than the typical severe threat we see around here. I won’t nerd out too much on the details of supercells (but if you want to here is an easy to understand article on them), just know they are the types of thunderstorms capable of producing the very big hail and large tornadoes seen in North Texas and on up through the plains; they are basically weather-porn to weather-geeks. Usually the atmosphere does not support those kind of storms in our part of the world but Sunday the atmospheric ingredients could come together to spawn a few. I do want to stress though that while supercell thunderstorms can be intense, they are also very isolated and will not affect the entire area if any develop.
SEVERE TYPES POSSIBLE ON SUNDAY
Tornadoes – While tornadoes are by no means guaranteed to occur, they are what people focus most on in severe threats so I will start there. As I mentioned above supercell thunderstorms are the type that can produce the large “Twister” like tornadoes typically seen in the central plains – but not every supercell produces a large tornado, and many won’t produce a tornado at all. However since these types of storms are relatively uncommon for our area it is worth highlighting the potential for a tornado or two that is larger than the typical branch-breaking, backyard trampoline flipping ones we usually see. If a squall line forms later in the day some spots could also see some smaller quick “spin up” tornadoes like we saw on Wednesday.
Hail – Supercells also enhance the risk of large hail. I don’t think we will see baseball or softball sized chunks of ice falling from the sky, but golf ball and ping-pong ball size hail may be possible – big enough to cause a few dents.
Wind – High winds, not associated with tornados are possible in both supercell and squall line storms. If a squall line develops the odds are higher that more of the area could see high wind gusts (60+ mph) as the storms would be affecting a much larger area. When tornadoes and hail are on the table the risk of high wind gusts tends to get ignored, but it can cause just as much damage as a small tornado.
Heavy Rain – It’s not as sexy as the other issues but it can be just as much as, if not more of a problem. Everyone who has lived in the Houston area for at least the past couple of years knows streets can fill up fast around here. This storm won’t be a widespread devastating event like Memorial Day or Tax day, but it could dump enough rain in spots to make roads impassable for a bit. Don’t be a dumbass and drive into water.
With all of that said nothing is guaranteed in meteorology forecasting. While conditions look to be ripe for strong storms it’s likely that not every single person will see severe weather. Until the event begins it is almost impossible to pinpoint exact neighborhoods and locations that will get the worst weather, and since storms can blossom quickly it is important for everyone to at least be aware of the situation and prepared to act if they find themselves under the gun.