In brief: Periods of heavy rain will track through Houston throughout the day today, especially along and north of I-10. Additionally, some strong to severe storms are possible this afternoon across the southern 2/3 of the area. Street flooding is a good bet today. Rain ends this evening with gusty winds overnight. But a stellar weekend awaits.
Today
So far this morning, heavy rainfall has been limited to the northern half of the Houston metro, this after some strong storms overnight brought numerous hail reports from Sugar Land through Missouri City and Pearland.
Areas between Cypress and Spring have seen 2 to 3 inches of rain since yesterday. The area that saw hail also received close to 1.5 inches of rain in many spots. Rain continues to jet along and north of Highway 59/I-69 in and west of Houston this morning and north of I-10 east of Houston. That’s going to be the general pattern for most of the day, where those areas see fairly persistent rainfall.
Severe weather risk
However, as we get into the late morning and afternoon hours, there will likely be at least a couple of more ambitious clusters of thunderstorms that develop south of those areas. This would be primarily along and south of I-10 across the Houston metro all the way down to the coast. Not to say we could not see a couple of these find their way north of the I-10 corridor into Liberty, Waller, or northern Harris County, but the severe weather focus today will be mostly south of there. Again, I-10 is not a magical barrier; it’s just a nice, easy demarcation line that most readers generally know.
As these storms wiggle through, any of them will be capable of producing 40 to 50 mph wind gusts, some large hail, and frequent lightning. As you get closer to, say, Freeport, Lake Jackson, Matagorda Bay, or as far south as Corpus Christi, there is also a little bit of “spin” in the atmosphere that could yield a storm that produces a tornado, so just be aware of that. The entire southern two-thirds of the area is in a marginal risk (level 1/5) primarily due to the hail risk, but also due to the wind and very isolated tornado risk.
Flooding risks
In terms of how much additional rain we see, the entire area away from the coast is under a Flood Watch from the National Weather Service in Houston, a slight risk (level 2/4) for excessive rainfall from the NWS’s Weather Prediction Center, and a Stage 1 Flood Alert here on Space City Weather.
What does that tell you? Street flooding is probably a good bet today. This is a good day to be weather aware if you have errands to run or appointments to tend to. Give yourself extra time to get where you need to go. This will be especially true in the second half of the day as the ground will be saturated, making some street flooding more likely.
How much additional rain should we expect? It will vary, but likely another 1 to 4 inches of rain through the duration of the event where it’s currently raining (as of 5:30 AM). South of those areas should see anywhere from a half-inch to 2 inches of rain depending on exactly how this afternoon’s thunderstorms align. The latest HRRR model’s depiction of additional rainfall through this evening is shown below. Don’t focus on specifics here, but you can see the general pattern of how things should flow.
The good news is that rain should be out of here tonight, so expect the rain to end from west to east from about 8 PM through 1 AM or so. Early evening plans will be dicey, but late evening plans may be ok. Just don’t drive through any residual flooded roads!
Eric will have another update on today’s weather situation by the afternoon.
Gusty winds
One last note: As the rain begins to wind down, and the front pushes through with the disturbance kind of wound up, we are going to see non-thunderstorm winds increase. This should be especially true near the coast and in the southern half of the area. Inland wind gusts should be on the order of 20 to 30 mph beginning after 6 PM. Some locally higher gusts are possible. Coastal wind gusts will be more like 35 to 45 mph, and gale warnings are posted for the bays and Gulf.
Winds should be at their gustiest from about midnight through 7 AM Saturday. Then, you’ll see them gradually subside through the day tomorrow.
Weekend
Other than the wind in the morning, tomorrow looks glorious with low humidity, sunshine, and highs in the mid-70s. Overnight lows will be in the 50s. Sunday looks just as nice or better with more sun and highs in the upper 70s to near 80 degrees. Enjoy the early May, comfortable weekend spring fling!
Next week
Looking ahead, temperatures do warm up a good bit, back close to 90 degrees by the time we get to Tuesday or Wednesday. Believe it or not, another May cold front may be in the cards for later next week. Details forthcoming on that, but additional rain and storm chances may be in the cards around then as well.
