In brief: Houston faces the threat of heavy rainfall, and possibly severe storms, on Thursday afternoon and evening. Beginning shortly after noon we’ll see stronger storms building north of Interstate 10. Eventually a (probably weaker) system will migrate toward the coast late this evening. Some additional rain is possible Friday before a prolonged period of hotter and sunnier weather.
The big picture
It may feel like déjà vu to be staring down yet another threat for storms and heavy rainfall, as it has been a truly wet spring for the Houston region. During the last 30 days, the majority of our area north of Interstate 10 has received at least 10 inches of rain, and locations further north, particularly in the Huntsville and Lake Livingston areas, have received in excess of 20 inches. This has led to significant river flooding, and we’re likely to see more of that in the coming days after storms this evening and overnight.
If you’re tired of it all, I don’t blame you. But I would also note, with some caution, that we’re about to experience a significant pattern change. High pressure will settle in, and after Friday the remainder of May looks very dry. Maybe not completely dry, but quite possibly so. This could set us up for another scorching June, not dissimilar to last year. So while significant flood relief is coming, we may begin to miss some rain in a few weeks. We’ll see.
Thursday
I’m not concerned about conditions on Thursday morning, which should bring cloudy skies and temperatures in the low-80s. However, beginning later this afternoon, perhaps around 1 to 3 pm, we’re likely to see the development of showers and thunderstorms to the north of Houston, in areas such as College Station and Huntsville. Conditions are ripe for heavy rainfall, as an upper-level system brings lift into an atmosphere filled with moisture.
Some of these storms may well be severe. There is enough instability to support the threat of damaging winds and possibly a few tornadoes. (Hail, at this point, looks like a lesser threat). However, my biggest concern lies with the potential for heavy rainfall. Most areas north of Interstate 10 are likely to see 1 to 4 inches, but with these kinds of storms bullseyes of 6 or more inches are possible this afternoon and evening. By or before midnight, the worst should be over for inland areas. Long-term, we’ll need to monitor ongoing flooding of the Trinity, San Jacinto, and Brazos river basins.
After battering inland areas, the system is likely to migrate southward later this evening, and push closer to the coast near midnight. Heavy rain remains possible south of Interstate 10, but the overall threat is less.
Friday
An additional, final round of showers and thunderstorms is possible on Friday morning. This activity should be clustered closer to the coast, where the boundary will get hung up. Expect highs in the mid-80s, with possibly some partially clearing skies by Friday afternoon or evening. Lows on Friday night will drop to around 70 degrees.
Saturday and Sunday
The weekend looks sunny. I’d expect highs to slot somewhere into the low-90s on both days, with nights in the low 70s. Southerly winds look light, so plan your outdoor activities with confidence (and sunscreen).
Next week
More sunshine is on the way. Generally we should see mostly sunny afternoons next week, with highs likely pushing into the low 90s for areas of Houston closer to the coast. Inland areas may get a few degrees warmer. It won’t be full-on summer, but it will be rather warm. Rain chances are not zero, but they’re close for most if not all of next week.