Eric Berger

In brief: So far Beryl hasn’t strengthened much today, but there is yet time for intensification before a final landfall tonight. This post goes into the likelihood of such intensification and what it would mean for Houston in terms of winds and the potential for power outages. We also look at the latest rain and surge forecasts.

Beryl status at 4 pm CT

As of this afternoon Beryl remains a tropical storm with 65 mph winds. Its central pressure has dropped a bit to 988 mb, indication a trend toward better organization. The storm is moving to the north-northwest at 12 mph and remains on course to make landfall near Matagorda between midnight and 4 am CT on Monday.

Intensity and track outlook

The fact that we’re not seeing significant increases in Beryl’s winds this afternoon is great news. The biggest threat to the greater Houston area from Beryl is damaging winds, and less intensification means less damage once onshore.

Beryl is running out of time to strengthen—that is not a taunt, mind you. Please let the record show I did not taunt Beryl. The storm will move inland in 8 to 12 hours. There is still time, and the waters are very warm with atmospheric shear low. However, forecasters at the National Hurricane Center note the storm is still struggling to shrug off some dry air in its core. They are still calling for an 85-mph, Category 1 hurricane at landfall, with the likelihood of rapid intensification this evening. This certainly seems plausible, but I am rooting for that dry air to keep disrupting things for just a little while longer.

In terms of track there is very little change to the system. Beryl should come ashore early on Monday, and pass near Katy a little before noon before it lifts further out of the Houston area. This rapid forward movement should continue, allowing the worst effects to begin clearing out of the city during the afternoon hours.

What to expect, and when to expect it

Tropical-storm force winds should reach the coast, near Matagorda Bay, around sunset on Sunday and push into Galveston Island a few hours later. The stronger winds will move into much of the rest of the metro area just before or after midnight tonight. The heaviest rains will arrive around the same time. Please find shelter a few hours before this.

How bad will the winds get?

For this outlook I am going to focus on the possibility of seeing sustained winds of 60 mph or greater, which is likely near the threshold for widespread power outages. The map below shows the National Hurricane Center forecast for the probability of winds of 58 mph or greater from Beryl. I’ve annotated it with circle that roughly denotes Loop 610. Winds at this speed likely will not cause roof damage (that threshold is higher, perhaps 70 to 90 mph sustained winds). The map clearly shows the risk for damaging winds and power outages is greatest to the southwest of Houston:

Several readers have asked about tornadoes. Yes, they’re possible within the rainbands of Beryl tonight and on Monday morning. However I expect their development to be fairly scattered, and the bigger threat for a majority of people will be winds directly related to Beryl’s circulation.

Some thoughts on power outages

I’ve spent a couple of hours today doing some digging to try and set some expectations for power outages tonight and later on Monday as the core of Beryl’s winds move into the greater Houston area. Our most recent tropical system with a major “wind” component was Hurricane Ike, a Category 2 storm that made landfall in 2008. It came ashore about 90 miles further east than where we expect Beryl, but it was a much larger and more powerful hurricane. Here is what Ike’s sustained winds looked like.

Ike knocked out power to 2.1 million CenterPoint Energy customers in Houston, and 10 days later the power remained out for about one-third of these customers. I want to be clear, I do not think Beryl will have this magnitude of an effect. Far from it, likely. But it’s useful to study the map of outages below and see where there were fewer problems (i.e. northwest Houston).

My back-of-the-envelope estimate here is that widespread power outages start to become more likely at sustained wind speeds of about 60 mph. The majority of Houston will probably less than this tonight, although such winds are likely in many areas of Brazoria, Fort Bend, and Matagorda counties. They are also possible west of Houston, in locations such as Katy.

My general expectation, therefore, is that power losses will be in the hundreds of thousands, and restorations in days; rather that losses above 1 million with a week or two of restoration. However that is a guess rather than a firm conviction, and given since so many people are understandably concerned about this issue.

Finally, I very much do not expect hurricane-force sustained winds tonight in any part of the Houston metro area apart from the immediate coast near Matagorda, and possibly locations such as Freeport or Lake Jackson. For what it’s worth, CenterPoint’s estimate for Category 1 winds is: “extensive damage to power lines and poles likely will result in power outages that could last a few to several days.”

The bottom line is that power outages will be a wait-and-see game. Good luck. Charge those phones now, my friends.

Let’s talk rainfall totals

We’ve seen some fairly widespread shower and thunderstorm activity today as Beryl’s outer rainbands have moved onshore. So far, it’s been fine. I expect to see additional storms this afternoon and evening, but it should be mostly manageable.

The main event should arrive at the coast a few hours before midnight, and push into Houston around midnight. Based on the latest modeling the “thickest” rain band will likely move through the city around 4 to 8 am, bringing intense rains that will quickly flood streets. Conditions should start to improve during the late morning hours. However I would expect to see additional rain showers later on Monday night and Tuesday due to trailing bands (which won’t be as intense). In any case, this is another good reason to stay home from this evening through Monday morning.

In terms of accumulations, it still looks like coastal areas face the highest risk, with totals of 5 to 10 inches likely, and accumulations further inland of perhaps 4 to 8 inches. What we’re most concerned about are more isolated areas that fall under the heaviest banding. These locations could see 10 or more inches of rainfall. It is impossible to predict precisely where these will set up, but the latest modeling is hinting at higher totals near Galveston Bay. We’ll see. We have a Stage 2 flood alert in place.

Storm surge

Peak storm surge levels, the combination of high tide and surge, should arrive on Monday morning the upper Texas coast. For Galveston Island and Galveston Bay, water levels are expected to be 4 to 6 feet above normal levels. Surge should be slightly higher in Matagorda Bay.

Final thoughts and plans for tonight

Beryl is on our doorstep, and its winds, rains, and waves will move into our area tonight. The key thing I’m watching over the next several hours is whether the storm starts intensifying, as a weaker Beryl will cause far fewer problems in Houston on Monday morning. As always, we will hope for the best and prepare for the worst. Please make plans to get home, or to a safe place this evening, and remain there through the morning hours on Monday.

Our next post will come around 10:30 pm CT tonight, and we’ll continue to post overnight and into Monday as this dynamic event develops.

In brief: Just a few thoughts to share on Tropical Storm Beryl tonight—basically some things I’ll be looking for on Sunday. If you’re looking for a nuts-and-bolts forecast of what impacts to expect in Houston on Monday, please see our post from earlier today, which holds up fine tonight. We’ll have a comprehensive update for you first thing in the morning.

When will Beryl start intensifying again?

As of late Saturday night, Beryl remains a high-end tropical storm with 60 mph winds. Its intensity has not changed much today, as expected, due to shear and entrainment of dry air. However, as we’ve been discussing, Beryl is moving into a more favorable environment tonight and on Sunday, and therefore it is virtually certain to re-strengthen.

One key question at this point is when Beryl starts to rev back up. This is because once Beryl starts to increase its winds, it likely won’t stop intensifying until it runs into Texas. So on Sunday I’ll be watching to see how soon Beryl’s winds start to increase, and how fast its central pressure (currently 993 mb) starts to fall.

The National Hurricane Center forecasts Beryl to come ashore as a Category 1 hurricane, with 85 mph winds. However, the forecasters there acknowledge that Beryl could rapidly intensify in the final hours before it comes ashore as the system reaches an environment with significantly lower wind shear. In addition, historically, we have seen hurricanes intensify as they near the Texas coast. The bottom line is that the later Beryl starts intensifying, the better, as it could easily become stronger than a Category 1 hurricane.

A silver lining: Beryl is moving at a good clip

One bit of good news is that the storm is moving a bit faster than expected, so it will have less time over water to get going. Some of our best models, including the European and GFS models, now bring the storm to the Texas coast around 2 to 4 am CT on Monday, several hours faster than previously thought. This will give Beryl less time to rapidly intensify.

The forward motion will also help with rainfall totals, both at landfall and after it moves onshore. Houstonians are justifiably jumpy when it comes to inland rainfall from hurricanes after Harvey, and this storm will make landfall only a little way up the coast from where Harvey did. But Beryl is no Harvey. In fact, the forecast for Beryl’s forward motion after landfall is also trending faster. So while I do expect to see some very intense rainfall in the Houston metro area on Monday, increasingly it looks as though the heavy rain will exit to our north by Monday night or early Tuesday.

We should have better clarity on Beryl’s impacts in Houston by tomorrow, as we’ll be less than a day before landfall. The bottom line is that everyone in the Houston area, but especially residents south and west of the city, should be prepared for heavy rainfall and higher winds on Monday. How much rain, and how strong the wind will be is something we’ll try to fully pin down in tomorrow’s forecast. This will, of course, depend to some extent on the rapid intensification (or not) of Beryl discussed above.

Have a good night, everyone.

In brief: We’re less than two days before the landfall of Beryl and there are still plenty of questions about the severity of impacts in Houston. This post will attempt to answer those that we can. In terms of planning, it is becoming increasingly clear that Monday, perhaps from the pre-dawn hours into early afternoon, will be the most impactful time for severe weather.

Status of Beryl on Saturday afternoon

Good afternoon. As of 4 pm CT, Beryl remains a strong tropical storm with 60 mph winds and a slowly dropping central pressure. It’s movement is northwest, and it remains on course to make landfall in Texas on Monday, likely during the morning hours. There remains a fair bit of uncertainty about precisely what winds, surge, and rainfall the greater Houston area will experience.

You’ve probably noticed the showers and thunderstorms—there has been a lot of thunder and a lot of excited dogs down my way—this afternoon. These storms are not directly related to Hurricane Beryl, but rather are due to a dying front meeting up with the sea breeze and having a party with the peak heating of the day. These storms should sag toward the southwest this evening before fading out by or before sunset. After that we can expect a quiet night, I think.

Starting on Sunday, perhaps by noon, we may see our first rains from the outer bands of Beryl. However, there should be few mobility issues with making final preparations before the hurricane reaches the Texas coast. I expect stronger winds to begin reaching the coastal areas on Sunday evening, so if you live in places such as Galveston Island or Freeport, you’ll probably not want to be out too late. After midnight our region will start to feel the full effects of Beryl, and which I’ll talk about below.

However, before jumping into the forecast I want to share a couple of housekeeping notes.

Housekeeping notes

Find us: There are lots of ways to find and follow Space City Weather online, and to be sure you know when we post updates. We’ve created a page to help you find us on social media, via our (absolutely free) app for your phones and tablets, an email newsletter, and more.

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Beryl’s track and intensity

As expected, Beryl is spending most of today fending off dry air to its south, and wind shear to its southwest. The storm is starting to develop better organized thunderstorms, however, and it should slowly begin to intensify tonight. Sunday and Sunday night will present a more favorable opportunity for intensification, and the National Hurricane Center brings Category 1 hurricane to the coast on Monday morning. However, the storm could be a bit stronger than this as historically we have seen hurricanes quickly gain intensity as the near the Texas shore.

We are now only about 36 to 48 hours away from a final landfall along the upper Texas coast. But there remains a decent amount of uncertainty in the final landfall location, and even 50 or 100 miles matter since the storm is going to come inland relatively close to Houston. Our forecast models are pretty good, but we’re talking about relatively small errors that can still be caused by a wobble or two.

What I’m trying to say is that Houston is sort of on the edge: Depending on which way Beryl goes in the last day and a half we could see anything from fairly minor winds to near hurricane-force gusts; and a few inches of rainfall up to 10 inches or more. So my main message here is to be prepared for some serious disruptions in power and mobility on Monday, and if we’re lucky these issues will turn out to be minor. The forecast conditions outlined below are consistent with the latest operational forecast from the National Hurricane Center, which is the most likely (but not certain) outcome.

Timing and severity of Beryl’s impacts on Houston

There are three main impacts from Beryl, winds, storm surge, and heavy rainfall. Let’s go through the latest thinking on each of them.

Winds: Tropical storm-force winds could reach the upper Texas coast by Sunday evening. Generally, areas along and west of Interstate 45 have the best chance of experiencing tropical storm force winds of 39 mph or greater, with higher gusts. In terms of potential power outages, I’m most concerned about Brazoria and Fort Bend Counties, and areas generally south and west of Houston. Again, the extent of our concerns about power losses will be driven by the potential for last second wobbles which will (or will not) bring the core of stronger winds closer to Houston.

Storm surge: Our thinking on storm surge has not changed much, with 3 to 5 feet expected along Galveston Island, and 2 to 4 feet possible in Galveston Bay. This surge is likely to peak on Monday morning, as Beryl nears land, and on top of high tide. Tide timings vary by location, but generally the highest water levels should be anticipated between 6 am and 9 am CT.

Rainfall: We’ve issued a Stage 2 flood alert for the entire Houston metro area, but like with Beryl’s winds, the risk for flooding is greatest along and west of Interstate 45. My best guess is that the strongest band of thunderstorms will move through Houston sometime on Monday morning, perhaps between sunrise and around noon. This likely will produce the most intense rainfall, and the greatest potential for rapidly flooding streets. If you have plans to be out and about Monday morning, please be very weather aware. In terms of accumulations I think most of the area will pick up 4 to 8 inches of rain, which is mostly manageable. However, due to the tropical nature of this rainfall (which leads to high rainfall rates) some isolated areas may pick up as much as 12 or even 15 inches. That’s … less manageable.

A note about flight cancellations

I mentioned this about three weeks ago, but I wanted to reiterate that we hear you on flight cancellations. It’s a major concern with inclement weather. I totally get the anxiety. However, neither Matt nor I are aviation meteorologists or pilots. Unfortunately, we don’t have any special expertise or insight into the decision-making at airports that lead to flight stoppages, nor the cancellation of flights. We try to be helpful, but we’re never going to be able to give you the certainty on this issue that readers want. With all that said, my general expectation is that heavy rain or winds may well disrupt and even cancel some flights on Monday or (less likely) Tuesday.

Our next update

We’ll be back late this evening, probably between 10 and 11 pm CT, with a short update on track, intensity, and some thoughts on whether Houston is likely to experience milder or more serious effects from Beryl. We will, of course, have full coverage on Sunday.