Good morning. Unfortunately the greater Houston region remains in an unsettled pattern, and the kinds of storms we’ve seen on Thursday and Friday afternoon and evening are likely again today—and possibly in even greater abundance.
There are two factors at play with our weather today. To start with we’re going to see a mostly sunny morning. This will lead to daytime heating, which in turn will help set up a sea breeze. This flow from the Gulf of Mexico should lead to the development of coastal showers early this afternoon, and we should see them move steadily inland. At the same time a weak, late-spring cool front will be moving down though Texas, southward toward Houston, bringing some additional instability with it. The weather concern is that the sea breeze and front essentially collide, in which case we’ll have a big party in the atmosphere for instability.
This means the potential for locally heavy rain, hail and possible severe thunderstorms, like we’ve seen the last couple of afternoons. Only potentially more widespread. Here’s how one model, the HRRR, suggests conditions will look at 6pm today.
HRRR model forecast for 6pm CT on Saturday. (Weather Bell)
Good afternoon. Matt’s forecast from this morning still holds up pretty well, but I wanted to provide a quick update on storm possibilities looking ahead.
FRIDAY EVENING
We’ve seen some strong thunderstorms fire up from the Lake Jackson area to Alvin this afternoon, and we’ll continue to see at least some scattered development through the evening hours as temperatures remain in the upper 80s helping to fuel these storms. Much of Houston will not see rain, but where these storms do fire up this evening they have the potential to be intense and flood streets. Small hail is also a possibility. I do not expect coverage to be quite as widespread at Thursday evening, but these things are hard to predict. Storms end by 9 or 10pm with the loss of heating.
Storms mainly have developed to the south of Houston this afternoon, but they may migrate further inland this evening. (Intellicast)
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!
