Eric Berger

In brief: There have been unexpected, and significant changes in the forecast for Tropical Storm Beryl over the last 24 hours. The implications for Houston early next week range from relatively mild to fairly impactful, and we’ve tried to set some expectations in this update. Expect much more from us this weekend as the Houston area now needs to pay closer attention to Beryl.

Houston and Beryl, my how things have changed

Over the last couple of days it seemed like it was within the realm of possibility that Houston might see some direct impacts from Hurricane Beryl, but it was a low-end probability. We wrote as much, and felt as much. But over the last 12 to 24 hours the models have undergone a dramatic shift as Beryl has tracked more north than anticipated, with these subtle changes now having a greater impact downstream. The trends have been universally bad for the upper Texas coast.

Just so you can appreciate this change, here is the shift in what is considered the best global model in the world, the ECMWF, and its forecast for Beryl’s landfall. The first image shows the model’s output at 7pm CT on Thursday, and the other one from 1 pm CT Friday, just 18 hours later.

The point here is that the models are still struggling with Hurricane Beryl, even though we are only three days from a final landfall. What once looked like a reasonably confident forecast has now been tossed out of the window. So I want to be clear that what we’re writing now is our best sense of how things will play out, but don’t be surprised if there are further changes. The greater Houston region is now at a significantly greater risk than things looked just a day ago.

Here’s what we know

As of this afternoon, Beryl has weakened into a tropical storm with 65-mph winds as it has traversed the northern edge of the Yucatan Peninsula. However it will soon move into the Gulf of Mexico. After Beryl moves back over water it will need some time to reorganize itself. The system is dealing with dry air to its south, and shear being produced by an upper-level low pressure system near South Texas. However, over the course of this weekend, as the system moves to the west-northwest, it should encounter less dry air, and lessening wind shear as the upper level low retreats west. Put simply: by Sunday or so, we should start to see Beryl get better organized, and this trend should continue as it moves toward the Texas coast, with a landfall expected on Monday.

The latest forecast from the National Hurricane Center, issued at 4 pm CT, shows a landfalling Beryl near Corpus Christi in the middle of the day on Monday. As a result of this, the National Hurricane Center has issued a “hurricane watch” for coastal areas from the Rio Grande Valley northward to Sargent, which lies at the northern end of Matagorda Bay (shown in pink, below).

This forecast notably keeps Houston, as well as Brazoria and Galveston counties, out of the hurricane watch area. However, it is entirely possible that the hurricane watch areas move further north, and eventually include Galveston Island. Given the trends we’ve seen over the last 24 hours, all bets are off.

Given the remaining uncertainty, in this forecast post I am going to write about two different scenarios, and the impacts on Houston. In the first scenario, Beryl comes inland along the current forecast track from the National Hurricane Center, shown above. Under the second scenario, we will assume the landfall of a 100-mph hurricane near Sargent, Texas. I consider this a low-end probability, say a one-in-10 chance; and also a reasonable worst case scenario for the Houston area. To recap, the two scenarios are:

OFFICIAL FORECAST: Sourced from the National Hurricane Center, and most likely

SARGENT SCENARIO: Less likely, but more impactful for the greater Houston region

Winds and power losses

Officially, the hurricane center predicts a Category 1 storm, with 90-mph winds, making landfall near Corpus Christi. In the Sargent scenario, we are assuming a modestly stronger storm, a Category 2 hurricane, further up the coast.

Under the official forecast scenario, Galveston Island has about a 1-in-3 chance of seeing sustained winds of tropical storm strength (39 mph), with higher gusts. Chances would be less in Houston, although non-zero. Areas to the west of Houston, including Katy, would have a decent chance of seeing those kinds of winds. Sporadic power outages are likely, although I would not expect to see widespread issues.

With a Sargent landfall, Galveston Island would be almost guaranteed to see tropical storm force winds, and they would be reasonably likely further inland, in places such as Katy and Houston. I think we would see some more widespread power issues, although I’m not envisioning something like half the region being without power.

Please note: In both scenarios the odds of seeing hurricane-force winds in the Houston region would still be quite low, as I expect Beryl to remain a fairly compact storm, with a relatively small area with the strongest winds.

Storm surge

Under the official forecast scenario, tides would run 1 to 3 feet above normal, not dissimilar to what Galveston and other coastal areas along the upper Texas coast experienced during Tropical Storm Alberto. This would not cause significant problems except for very low lying roads near the coast.

Under the Sargent scenario, storm surge levels would rise 3 to 5 feet above normal along Galveston Island and Galveston Bay, with the most impactful time likely coming at high tide on Monday morning in the Houston region. This still would not be an exceptional surge, but it could be disruptive for coastal areas.

Inland rainfall

Under the official forecast scenario, the greater Houston area is expected to receive 2 to 5 inches of rain next week, with the period of heaviest rainfall occurring from Monday morning through Tuesday night. We would see some higher bullseyes, of course, and probably necessitate us issuing a Stage 1 flood alert. We’ll make a final determination on that on Saturday morning.

Under the Sargent scenario, the core of heavier rainfall would likely line up more directly over the Houston region, with the potential for widespread totals of 4 to 8 inches of rainfall, and higher bullseyes. This likely would necessitate a Stage 2 flood alert, or possibly higher. Again we’ll make this call on Saturday morning.

Timing of all this

For the greater Houston area, I don’t anticipate significant disruptions on Saturday or, most likely, all of Sunday. The strongest winds would probably cross our area on Monday, and the heaviest rains on Monday and Tuesday.

We still have a little bit of time to watch this storm and observe trends. However, it is important to pay attention to forecasts over the weekend to better understand how impactful (or not) Beryl will be to the greater Houston area early next week.

Our next forecast will be issued on Saturday morning. We will be watching closely for further track changes, as well as indications that Beryl will rapidly strengthen over the Gulf of Mexico (right now there’s no strong signal for that). Thank you for your patience as we struggle to get a handle on what is proving to be a dynamic forecast.

In brief: We are sharing this post from our companion site, The Eyewall, on the effects from Beryl across the state of Texas. If you’re looking for a TL;DR for Houston, it is this: Continue to monitor trends today and tomorrow. Make whatever preps you feel comfortable making or you feel are warranted. Current forecasts keep most meaningful impacts beyond localized flash flooding away from us.

Beryl’s future track

Beryl is going to be walking an absolute tightrope over the next 2 days. I say that for residents of Texas, because as Beryl turns, exactly where that turn occurs will have an outsized impact on who sees exactly what. For now, I think the key player is this trough over the Plains. Over the last 48 hours, models have tended to further strengthen the trough. That coupled with a slightly farther north track of Beryl has led to Beryl being able to “feel” the tug of this trough more, which is forcing Beryl to come a little more to the north when it gets into the western Gulf of Mexico.

So what exactly does this mean for Beryl’s forecast track? When you look at the 51 member European ensemble now, you can see that the majority of the members are turning Beryl northwest or even north northwest into Texas.

The problem is two-fold. First, where exactly does that turn to the north northwest occur? That will determine the landfall point on the Texas coast. Secondly, that landfall point will have tremendous impact on who sees what. A landfall in Matagorda Bay means the southwest suburbs of Houston could experience a full fledged tropical storm type outcome, whereas Corpus Christi would be pretty much fine. A landfall in Baffin Bay south of Corpus would likely deliver hurricane impacts to Corpus Christi and few impacts to Houston beyond thunderstorms and rain. Storms approaching at an angle, rather than more perpendicular to the coast provide a world of problems from communicating impacts. Literally a 15 mile change in the angle of approach can add or remove entire counties from certain expected impacts. My hope is that we’ll get some additional color on this by afternoon, and we will have another update this evening with the information.

How strong will Beryl get

Beryl’s intensity will be contingent, somewhat, on what it looks like coming off the Yucatan. Assuming some organization still, as well as tropical storm status should allow it to begin to quickly re-intensify. The waters of the Gulf, or the oceanic heat content available to Beryl is not inconsequential, but it’s also not the Caribbean rocket fuel that it had on the other side of the Yucatan.

Still, this argues for steady intensification as Beryl comes toward the Gulf. Water temperatures immediately adjacent to the Texas coast are quite warm, so Beryl will not weaken on approach and should make landfall as a strengthening storm. Most modeling keeps Beryl as a tropical storm or a low-end hurricane as it comes ashore. The NHC forecast is slightly more aggressive than this, which is a stance I wholeheartedly agree with. I would plan for a borderline category 2 storm at landfall and hope for the best. The radius of hurricane force winds is currently only 30 miles out from the center, so Beryl is a relatively small storm. Do not focus on the intensity of Beryl other than if you live along the immediate coast, as this will likely deliver tropical storm wind impacts to most. However, widespread tropical storm winds and localized hurricane winds will still cause power outages and damage and should be respected.

In addition, while we don’t currently have a storm surge forecast, it is safe to assume that Beryl will deliver a surge and coastal flooding between Corpus Christi and Cameron Parish, LA. We will have more details on this to come, but expect something similar to Alberto’s impact last month, with pockets of worse conditions near and to the north of where the center comes ashore.

Beryl also a heavy rain and flooding concern

In addition to the hurricane impacts we normally see, Beryl will be a heavy rain producer for Texas. The current rainfall forecast is calling for locally 6 to 8 inches of rainfall, but I fully anticipate that this forecast will be upgraded some before all is said and done. Double digit rainfall totals are likely in a few spots with the most persistent rainfall and localized flash flooding is going to be a concern.

Beryl will not stall, so I want to make clear for folks in Texas that this is not a Harvey redux. However, Beryl will move slowly once ashore. Even relatively more progressive and faster models like the GFS dump up to 10 inches in spots. So the heavy rain concern is there. Expect more color on this later today as well.

The bottom line

For folks in the Rio Grande Valley: If you live in a flood prone area, keep an eye on the rainfall forecast for Beryl. Wind impacts will likely be confined to Brownsville and the coast.

For folks on the Lower and Middle Texas Coast and Coastal Bend region, including Corpus Christi: Prepare as if a hurricane is coming and make sure to follow local officials guidance in terms of evacuation if needed.

For folks in the Matagorda Bay area: Start making preparations in case the forecast shifts to the north and brings hurricane conditions closer to the area.

For folks in the Houston area: Continue to monitor trends today and tomorrow. Make whatever preps you feel comfortable making or you feel are warranted. Current forecasts keep most meaningful impacts beyond localized flash flooding away from us. Coastal residents prepare for at least minor to moderate tidal flooding.

In brief: The track for Hurricane Beryl has shifted northward during the last 24 hours, and a landfall is now expected near or south of Corpus Christi. This does increase the threat of significant impacts to the Greater Houston area, but we continue to think the system will be mostly manageable locally. Needless to say we’re following things closely.

Hurricane Beryl track changes

During the last 24 hours we have seen a significant move northward in the track forecast for Hurricane Beryl, which has just moved into the Yucatan Peninsula this morning. The storm, with 100 mph winds, has remained a little stronger than expected, and this supports the notion of a sharper northwestern turn in the coming days. This post will discuss the current thinking of Beryl, and its impacts to Houston’s weather early next week, which could now but a little more significant than anticipated.

In terms of additional coverage, we will share a post from The Eyewall here later this morning on the broader effects for Texas. And we’ll have an additional update this afternoon on the latest with Beryl. But first, a quick look at the forecast for this weekend.

Friday

Today will be our last hot and mostly sunny day for awhile, given the impending influx of tropical moisture. Look for highs in the upper 90s to 100 degrees for most inland locations, with slightly cooler temperatures near the coast. Winds will be very light, perhaps at just 5 mph from the south. There is perhaps a 10 percent chance of afternoon showers. Lows tonight will drop to around 80 degrees.

Saturday and Sunday

Rain chances increase to about 50 percent on Saturday as a weak front approaches the Houston metro area from the north. This is not going to bring much (any, really) cooler or drier air into our region, but it should help increase cloud cover, and allow for air at the surface to rise. Rain accumulations don’t look crazy, more on the order of passing, scattered showers most likely. As a result of the cloud cover, look for highs in the mid-90s.

By Sunday our weather may start to become influenced by Beryl, but the storm is now not expected to come to the Texas coast until Monday morning. My best guess for Sunday is highs in the low 90s, with partly to mostly cloudy skies, and perhaps a 50 percent chance of rain. This is unlikely to be heavy rainfall, as the threat of that probably holds off until Monday. Southeasterly winds will increase.

Hurricane Beryl’s track

The northward shift in Beryl’s track can be attributed to a stronger system over the last day or so, and something of a northward wobble on the Fourth of July. Our typically best performing models, including the GFS and European, and the hurricane specific models, have all shifted northward overnight. They now generally indicate a landfall between Brownsville and Corpus Christi about three days from now.

Where Beryl ultimately makes landfall will depend on how far the high pressure system over the southern United States retreats. The landfall location is complicated by the contour of the South Texas coastline, which is very nearly north-south relative to the Gulf of Mexico. This means that, as Beryl turns northwestward around the ridge of high pressure, even a relatively small deviation in course can change the landfall location significantly.

Regarding Houston, I would love to be able to tell you with certainty that Beryl will make landfall near or south of Corpus Christi. I truly think that will be the case. But as Beryl’s track has moved significantly in the last 24 hours that is not something I can guarantee you. The entire Texas coastline, for what it’s worth, lies in the National Hurricane Center’s cone of uncertainty.

Beryl’s intensity

Beryl made landfall in the Yucatan Peninsula this morning, and will spend most of today traversing the Mexican peninsula before emerging into the Gulf of Mexico this evening or tonight, likely as a strong tropical storm. The storm will then have about two days, or a little longer, to re-strengthen over the Gulf of Mexico before making a final landfall late on Sunday night or, more probably, Monday.

Given that Beryl will have plenty of time over the Gulf, it is likely that the storm intensifies back into a hurricane. Nearly all of our guidance shows the system remaining a Category 1 hurricane as it nears the Texas coast, but certainly we cannot rule out a slightly stronger storm.

Houston impacts

At this time the Houston area is still unlikely to see severe impacts from Beryl, but obviously we are watching the situation closely due to the evolving track. I would anticipate about a 20 percent chance of Galveston experiencing tropical-storm force winds on Sunday or Monday, with lesser odds for inland areas. In terms of storm surge, at this point Beryl should remain far enough south to preclude a significant surge into Galveston Island and Galveston Bay. We are talking tides maybe a few feet higher than normal, not dissimilar to the effects of Tropical Storm Alberto a couple of weeks ago. Obviously we’ll monitor this closely.

What hasn’t changed much is the precipitation forecast. Much of the Houston area is still likely to see 2 to 4 inches of rainfall over the coming week. Our concern remains the potential for higher bullseyes, driven the tropical nature of rainfall from Beryl, on Monday, Tuesday, and Wednesday. That is something we have not had great confidence in predicting, and still don’t. But the bottom line is that there remains no signal for major flooding in the Houston area at this time.

Final thoughts

I realize some readers will be disconcerted by the changes in Beryl’s track. It has been a surprising move, but not one out of the realm of probability, and this is ultimately the nature of tropical weather. Matt and I don’t think there’s a great chance that Beryl comes inland into Texas north of Corpus Christi. But is there a chance that could happen? Yes. It is certainly higher than it was on Thursday when we looked at the data. We are at the point where the greater Houston region, including Galveston Island, should be wary of Beryl, but not overly worried. Expect multiple updates today to keep you as best informed as possible.

In brief: Happy Fourth of July! We have hot and sunny weather on tap for the holiday to celebrate the birth of America, and Friday will be hot as well before rain chances increase due to the movement of Hurricane Beryl into the Gulf of Mexico this weekend. It still appears as though the system will track well to the south of Houston, with the only major impact being the potential for rain.

Thursday

High pressure will remain in place for a couple of more days, and that means mostly sunny skies and soaring temperatures in early July. Look for highs today in the upper 90s for much of Houston, away from the coast, with generally light southerly winds. There will be about a 10 percent chance of showers this afternoon along the seabreeze. By the time of fireworks this evening, temperatures will still be in the upper 80s, at least. Lows tonight will only fall to about 80 degrees.

Friday

Another day a lot like Thursday.

Saturday and Sunday

The forecast for the weekend and next week is predicated on the outlook for Hurricane Beryl, discussed below. Our confidence is increasing in this forecast, but it is possible there are still some subtle changes. Anyway, skies should be partly sunny on Saturday, with perhaps a 50 percent chance of light to moderate rainfall. Temperatures still have a chance to hit the mid- to upper-90s for some inland locations. Sunday will see partly to mostly cloudy skies, with highs in the low- to mid-90s. There is, again, a healthy chance of light-to-moderate rainfall.

Next week

The remnants of Beryl, and tropical moisture from another disturbance, should bring mostly cloudy skies and lower temperatures for much of next week. Daytime highs probably will be in the range of the upper-80s to lower-90s. Each day will have a medium to high chance of rain, with the potential for tropical downpours. In terms of rainfall accumulations, I’m not seeing any extreme signal that will lead us to issue an alert on our Space City Weather flood scale, but that could change. Overall, I expect much of the area to pick up 2 to 4 inches of rain next week, although that remains a first-order approximation at this point.

Hurricane Beryl

The hurricane is weakening in the face of moderate wind shear, with maximum sustained winds of 120 mph as of 7 am CT. It will reach the Yucatan Peninsula on Friday, and emerge into the Gulf of Mexico on Friday night, likely as a weak to moderately strong tropical storm. Beryl will then have about two days over the southern Gulf of Mexico to strengthen. Seas are plenty warm, but there will be at least a bit of wind shear. Most modeling guidance brings a strong tropical storm or Category 1 hurricane to the western Gulf coast by around Sunday night. We’ll have to see about that.

In terms of track, the most likely landfall position remains somewhere within 50 or 100 miles south of the Texas-Mexico border. However, because this landfall remains about four days into the future, uncertainty remains. It is possible the storm could track more northward, and make landfall along South Padre Island or a bit further up the Texas coast; or further south, in Mexico near Tampico. Regardless, for Houston, the primary impacts are likely to be increased rain chances. For more information on impacts to Mexico and Southern Texas, please see our latest updates at The Eyewall.

We’ll continue tracking all of this today, and if anything significant changes we’ll update the site. If not, we’ll see you on Friday morning.