Note: Braniff Davis, who is finishing a master’s degree in meteorology from San Jose State University, is joining Space City Weather as a contributor. He and his wife will be moving to Houston this summer, and he’s offered to help explain the why’s of Houston’s weather, and will also be tracking air quality and related issues for the site. Please welcome him!
On Monday, May 9th, the Houston metro area woke up to a strong wind event that rattled the region. Weather stations measured sustained winds over 20 mph and wind gusts in excess of 40 mph, with a station southeast of Missouri City picking up a regional maximum of 51 mph at 8:22 am.
Max wind gusts on May 9, 2016. Map created using MapBox.
In Houston and along the Gulf Coast, there’s no definitive “start” to summer. As a meteorologist however, I usually signify the true start to summer here as being when you have to include a chance of thunderstorms in the forecast almost out of pure obligation. Maybe you get one or two and the majority of the region stays dry (though, hey, last night was a little wild, right?), but you are obligated to include that chance. I feel like that really started yesterday. You may have your own definitions on when summer truly begins, but I am arbitrarily declaring summer in session. Away we go…
TODAY
You may wake up to some fog south of Houston, but the radar is mostly quiet this morning. A weak cold front will essentially wash itself out over the area today. It’s basically along or just south of I-10 this morning, and it probably won’t get much further.
Texas Tech WRF model forecast radar for mid-afternoon: Best chance of storms S & W of Houston. (TTU)
The models generally agree that the best chance of storms today will be south and west of Houston. That doesn’t mean we couldn’t see one pop up anywhere in the region today, but the odds are highest toward Wharton, or El Campo. We will heat up enough to develop a sea breeze off the Gulf, so that may also act to focus some pop up storms elsewhere in the region. Otherwise, hot and humid. We fell just short of 90 yesterday, and I think we’ll fall just short again today, but it’s going to be close. Upper 80s to 90ish inland today, but if you get a cooling shower, it’ll drop into the 70s for a time.
SATURDAY
Another weak cold front will try, but fail to get through the area. The first half of the day looks good, but as that front approaches, we could see showers and storms kick off. Unlike Friday, I think the best chances will be north and west of Houston during the afternoon, perhaps closer in during the evening. So if you live in Brenham, Conroe, or Livingston, your chances are higher tomorrow afternoon. In Houston, if you’re planning to check out the Dynamo/Real Salt Lake match or perhaps Rice baseball against Florida Atlantic, keep the threat for evening storms in mind. If we can hold the rain off enough, there may be an outside shot at 90 degrees Saturday, but it won’t matter much either way: Continued hot and humid.
High temps for Saturday may make another attempt at 90°. (Weather Bell)
SUNDAY INTO NEXT WEEK
Sunday will be a bit tricky. Saturday evening’s storms will form along yet another cold front trying to drop into the region. That will be weak, but it could act as a focal point for some hit or miss storms during the daytime Sunday. If I absolutely had to put a number on it, I’d say about a 20-30% chance of a daytime shower or storm basically anywhere in the region.
Sunday night into Wednesday night (or beyond) is when things could turn interesting here. I’m anticipating at least two rounds of thunderstorms. The best windows for rain are Sunday night into Monday afternoon and again Tuesday night into Wednesday.
Upper level maps show an anomalously cool pattern next week across the US. (Weather Bell)
A rather strong upper level weather pattern for mid-May will pester the Eastern 2/3 of the US next week. This means abnormally strong cold fronts can get abnormally far south. You see where this is going.
Monday is low confidence. The European model has been aggressively showing heavy rain and thunderstorms Monday, whereas the GFS has been sort of agnostic about the whole thing and just shows some scattered showers or storms (though it did trend a little stormier overnight). Right now, I’d split the difference and say a good chance of scattered showers or storms, possibly coming from a large complex of storms that moves from Central Texas late Sunday night. Honestly, details are very much TBD at this point. We’ll keep an eye on this for you over the weekend, and we’ll probably update you on Saturday afternoon or Sunday morning.
Oddly, the forecast for Wednesday may actually carry slightly higher confidence than Monday. A cold front will likely approach and potentially clear the region. A band of heavy rain and thunder should accompany this one. If we’re lucky, we may get a day or two behind that front with slightly lower humidity to round out next week. Fingers crossed. If the front stalls, then forget that, and we’ll add more thunderstorm chances late next week.
Amount of rain needed in one hour to trigger flash flooding. (NOAA/NWS)
In terms of severe weather and flooding: As is always the case in May with storms in Texas, both are possible. In terms of severe weather, there isn’t anything alarming for any day, and the main threats would be large hail and strong, damaging winds. In terms of flooding: We’ve had ample time since Tax Day to dry out and can handle a fair bit of rain right now; in fact, most areas could feasibly handle 2-3″+ of rain in an hour before flash flooding becomes a serious issue. As we saw last night, that’s not impossible to do though, so while I’d classify a serious, widespread flooding risk as low right now, localized street flooding is likely to be an issue at times in parts of the area. It’s something we will continue to monitor, and we’ll keep you posted as we get closer and throughout!
A line fairly strong thunderstorms has developed this evening to the west and southwest of Houston, bringing locally heavy rains, intense winds and dime-sized hail. These storms are moving slowly to the east-southeast.
The area of heaviest storms as of 9pm is indicated below:
Area of heaviest storms through 9:30pm CT. (National Weather Service)
So far bayous are holding up fine, but there is some localized street flooding beneath the heaviest rains.
Some of the latest modeling suggests these storms may intensify for the next couple of hours, before weakening later tonight. If they’re going to present an ongoing threat we’ll update the site later.
It’s another morning with 100 percent, or near 100 percent humidity across the area, and lows generally in the mid-70s across the area.
TODAY
There were strong storms during the overnight hours in the Dallas-Fort Worth metroplex, but as the associated system has sagged to the southeast it has weakened. This should leave the Houston area with partly to mostly sunny skies for the first half of today. A slow-moving, weak front will then push into the area later this afternoon. There’s some chance of thunderstorms with this system, but at this point there just doesn’t seem to be enough lift with the front to really drive widespread showers. Most areas probably won’t see rain as the front slowly moves through Houston this afternoon, evening and tonight.
Approximate location of the cool front this evening from 7-10pm CT. (National Weather Service)
