Matt Lanza

A tricky forecast for rain chances this weekend in Houston

Good morning. It was quite a wet afternoon and evening on Thursday, though outside of a few areas of localized flooding, the rain didn’t cause too much heartburn. Except in Deer Park, where it looks like a microburst (strong, straight-line winds) inflicted some damage in the area around the high school.

With continued chances at rain, we will continue to carry our Stage 1 Flood Alert into at least Saturday.

Before we jump into the forecast details, in case you missed it, Space City Weather now as an app available for both Android and Apple users! You can check out Dwight Silverman’s introductory post for more details. And please, if you notice any bugs or issues, shoot us an email at [email protected]. We’ve gotten lots of feedback so far, and we will do our best to address your reports in a timely manner! I just want to personally thank Dwight, Eric, and especially Hussain Abbasi for getting us here. It’s just a really good, clean, functional app, and I’m thrilled we can share it with you all.

Alright, let’s get into this somewhat tricky forecast.

Today

Radar this morning shows that most heavy rain has pushed offshore south and east of Houston. There are some scattered showers, including a few downpours in spots west of Houston.

Morning radar shows mostly nuisance showers west of the city with organized rains offshore. (RadarScope)

Storms should get going again along the sea breeze this afternoon, as it pushes inland from the Gulf. There’s a certain degree of randomness to these things. Yesterday’s rain began on the sea breeze and then transitioned to a widespread steady but lighter rain as a disturbance coming out of central Texas intercepted the sea breeze boundary. Today may be more hit and miss, but risk for areas of heavy rain will continue. Atmospheric moisture remains fully loaded, but instability, which we need to really get things popping, looks to be down a bit today. Expect at least some rain and some pockets of heavier rain, but at this time, we don’t expect widespread heavy rain today. We will let you know if that expectation changes.

Tonight through Sunday

We supposedly enter the heart of this rainy period tonight and tomorrow as the upper low ejecting out of Central Texas meanders north and east past our area. As this happens, we may, for a time, maximize the ingredients necessary for periods of rain and storms, and this is where we will watch for more widespread heavy rainfall chances and more notable street flooding potentially. I say “supposedly,” because there’s been a shift in modeling today, which favors areas east of the Houston area, mostly in Louisiana for the heaviest rain risk. Upper lows are notoriously tough to forecast and little changes like this can lead to big expectation changes. We will keep you posted through the weekend.

So between tonight and Sunday, don’t expect it to rain the entire time, but there will be periods of showers, storms, and locally heavy rainfall. We think Saturday may have the highest chances for that to happen, with perhaps the worst of the action shifting out of our area by as early as Saturday afternoon and staying east of us Sunday. That doesn’t mean a dry weekend, but it does perhaps allow for more frequent breaks in the rain. Most outdoor plans this weekend will likely need to be either a true game time decision or postponed if you would rather not deal with the hassle.

Taking the glass half full approach (depending on your point of view, of course): We typically start to ramp up into summer heat around now, but there is absolutely no heat to be found thanks to the clouds and rain. Highs this weekend will generally be in the low-80s with lows in the 70s.

How much more rain? Between now and Sunday evening, we expect that most areas will see another inch or two on average.

Another inch or two of rain is likely on average between now and Sunday evening, though some areas will see more and others less. (Weather Bell)

Some places will almost certainly see more, while some other locales may see a bit less. Again, the Stage 1 Flood alert we have posted is meant to cover for those handful of locations that see mostly nuisance street flooding like we saw yesterday.

Next week

I fully expect more rounds of showers and thunderstorms to start next week. Monday and Tuesday look like they will have the highest odds of wet weather. But I don’t see a truly dry day area-wide before next Wednesday at the earliest.

Unsettled start to Houston’s Memorial Day weekend will likely evolve into a pretty nice one

Happy Friday! Before we dive into the forecast, I just want to give a shoutout to Tim Zacharias at Cougar USA. I sat down with him a few weeks back on their Building Value podcast, and I got to talk a bit about Space City Weather, flooding, the freeze, and hurricane season. You can check it out on YouTube, iTunes, or Spotify. If you watch on YouTube, you get the added bonus of seeing Mullet Matt’s pandemic hair (which is now gone, thankfully!).

On to the forecast, as we have some things to discuss.

Today

Things are quiet around Houston this morning. Lingering storms from last night are moving southeast up north of us, across Walker, Trinity, and Polk Counties. These storms will weaken, but the boundary they’re leaving behind is likely to become the focal point for thunderstorm development this afternoon closer to Houston.

Two models, two different outcomes forecast for 1 PM CT, with the HRRR aggressively developing storms this afternoon, and the NAM being a bit less excited. Both models do suggest storms will develop in spots though. (WeatherBell)

Storms today could become fairly strong and locally severe, so don’t be shocked if you see a couple warnings in a few spots get triggered this afternoon, particularly for hail or strong winds. Some models are more aggressive than others with storm development this afternoon, so it’s certainly possible that some neighborhoods don’t see much of anything today, but a majority of the ingredients we need for storm development today are in place, so I wouldn’t go umbrella-free this afternoon. High temperatures will likely top off in the mid to upper-80s.

Tonight into Saturday

Additional storms are going to develop across northern or central Texas later today, likely congealing into a cluster of organized storms. Those should advance into parts of our area tonight, with the timing somewhat in flux. Early evening plans may see lingering isolated showers or storms, while late evening plans risk running into this more organized activity. Either way, have an umbrella. Storms tonight could again be strong to locally severe, with wind gusts being the main thing to watch.

Those storms will likely ease up Saturday morning, but with lingering boundaries, and yes, a bonafide cold front in the neighborhood, we should see additional isolated to scattered storms tomorrow through the day. Clouds, showers, and a slightly cooler air mass should allow morning lows in the 60s & 70s to only warm into the lower or maybe middle 80s.

Total rainfall the next couple days will be quite sporadic, with some areas seeing under a quarter inch, possibly near-zero, and other areas seeing as much as an inch or so. The map of NWS Houston’s forecast here should be considered an “average.” (WeatherBell)

How much rain? It will vary. I wouldn’t be shocked to see some places end up with next to nothing from this and others perhaps seeing an inch or two. We don’t expect any serious flooding concerns at this time.

Sunday & Memorial Day

Alright, good news. Both Sunday and Monday still look good. We should see sunshine on Sunday and maybe a bit more cloud cover for Memorial Day. That cold front won’t usher in super refreshing air, but it will skim just enough off the top with respect to humidity that Sunday should be kind of comfortable for Houston in late May. Monday should be similar, but it will be a little warmer. Look for low to mid-80s on Sunday and mid-80s on Monday. Both mornings should see lows in the 60s away from the coast.

Later Next Week

Look for any vestiges of comfortable weather to disappear by Tuesday, with lows in the 70s and highs in the mid-80s. Rain chances will begin to inch up, probably just a little on Tuesday but more on Wednesday, Thursday, and Friday. It’s tough to determine the details, but another slow moving upper level system is likely boost rain chances in our area as the week rolls along. This will keep temperatures cooler than average (mostly mid-80s), but hopefully we’re able to avoid heavier rains. We’ll update this for you certainly on Tuesday, but perhaps Monday if we have any more clarity.

Meanwhile, enjoy the nicer weather later this weekend!

Houston faring just fine, as we watch heavy rain risks nudge south of the city

I have to admit, I enjoyed Eric’s somewhat euphoric post at midnight. Though as the parent of a toddler and infant that slept — how can I say this? — poorly, for lack of a better word, it was a long night. I’m sure many of you with kids and pets can relate!

But seriously, although it was a wild evening, the city of Houston and most of the metro area are doing fine this morning.

Flood Scale remains Stage 2

That said, I am going to hold our flood alert at Stage 2 out of an abundance of caution. Based on model data, I think most areas north of I-10 are realistically down to Stage 1 concerns going forward, as most rain is projected to fall south of I-10 today. Given some heavier rains already this week south of Houston (and east of Houston), I just think we should hold at Stage 2 and watch the next cluster of storms later this morning and afternoon that may graze those areas, and just make sure tonight looks to avoid anything serious in Houston. Forecasting this has been and remains tricky, and as expected, the evolution of the storms has not gone quite as modeling suggested even 1 to 2 days ago.

The NWS intends to keep Flash Flood Watches going through midday Thursday for the entire area.

Water levels

A look at the Harris County Flood Control map of water levels as of 6 A.M. shows only a handful nearing bankfull or out of their banks.

With the exception of just a few locations, bayous remain in their banks this morning with minimal problems across the area. (Harris County Flood Control)

Expect just some minor lowland flooding in spots.

We will need to watch some primary river levels in the coming days, particularly southwest of Houston (though the Brazos looks to remain below flood stage in our area for now), as well as the Trinity River east of the city, which is currently forecast to approach major flood stage at Liberty by the weekend.

The Trinity River at Liberty is expected to approach major flood stage by the weekend. (NOAA)

This would yield significant lowland flooding and some house flooding potentially as well. We’ll keep you posted on this, as there could still be some changes to river forecasts as the future rainfall forecasts are revised.

Today

Rain continues in the Houston area this morning, but it’s falling at the rate of about a quarter-inch or less an hour. That is manageable and should not cause any additional serious trouble.

Our attention will focus to another cluster of storms developing over Mexico this morning. The good news is that this seems to be lined up to stay well south of virtually the entire Houston area. We’ll probably see rain or showers continue through mid-morning, and there will continue to be a chance of showers through the afternoon. But any organized, heavy rainfall likely stays well south of Houston.

A moderate risk of excessive rainfall is noted today from I-10 south to the coast, but the highest risk of problematic rains appears to be from about Matagorda County southward. (Pivotal Weather)

The Weather Prediction Center arm of NOAA continues a moderate risk of excessive rainfall, essentially from I-10 south to the coast. And this may even be skewed a bit far north given trends on models this morning. The biggest problems will most likely be from Matagorda County south past Corpus Christi. But if current trends hold, even Matagorda County may not be too bad. But they have seen 3 to 4 inches of rain since midnight south of Bay City.

Tonight and Thursday

The good news is that it appears that models have tapped the brakes a bit on significant, widespread heavy rainfall in this timeframe. That doesn’t mean it won’t rain. It also doesn’t mean we’re entirely out of the woods with respect to flooding risk. But at this point, there seems to be a lack of model data arguing for serious rainfall tonight or tomorrow.

So, let’s call it a chance of showers and thunderstorms at virtually any time tonight or tomorrow. If a storm does develop it will be capable of producing heavy rainfall. But at this point we don’t expect significant, widespread rainfall. We’ll continue to monitor for any changes.

Friday

There are some indications on models that the atmosphere may recharge a good bit by Friday, with more available atmospheric moisture. This could lead to another round of heavy rain and storms, but details are fuzzy. This might be a period to keep an eye on though. Improving conditions will arrive this weekend.

Eric will have our next update before 2 P.M.

Severe storms racing into the Houston area Tuesday evening

Storms are absolutely hauling their way into the Houston area tonight, faster than most of us expected earlier today. Good news, as you’ll see below. But they are intense. Rain is falling at a rate of 3 to 4 inches per hour on average in that intense red portion of the line bowing across Rosenberg, Cinco Ranch, and Cypress at 9:45 P.M.

Intense storms with torrential rains were moving into the Houston area at 9:45 P.M. Tuesday (RadarScope)

These types of rain rates will almost certainly produce street flooding across many parts of the region through Midnight, spreading east and south.

In addition, there have been multiple tornado warnings issued with these storms, including one storm that may have well produced a tornado just north of Brookshire earlier. Stay alert and aware, and seek shelter if a tornado warning is issued in your area. As of this writing, there is a tornado warning for the northwest side of the city through 10:15 P.M. Even with no tornado, strong, damaging winds are possible.

So, some good news about all this at least: That the storms are moving quickly is positive because, while it’s going to rain much of tonight, the super-intense, “floody” 2 to 4+ inch per hour rates will be short-lived over a given area. We can manage a steady rain. It’s when you get that overly intense stuff for more than an hour or two that things get out of hand.

Beyond tonight? Truthfully, I don’t have a great feel on what to expect tomorrow at this point. I think some of that will depend on how these storms evolve over the next several hours, and what happens back to our west overnight. Some models redevelop storms in parts of the area. Others give us a nice break between storm chances. It’s a tough call right now, so you’ll need to be fairly flexible and adjust with the forecast tomorrow. We do know that there will be more storms, but how intense and exactly where they hit matters a lot, and we just aren’t sure yet.

Eric will have an update on what’s happening here after midnight tonight.