Eric Berger

POSTED AT 10:30 AM CT WEDNESDAY: Just a quick, mid-morning update to share the latest information from the National Hurricane Center, and drill down a little bit more into what you should expect tonight, and when, in the Houston area. The storm has unfortunately continued to intensify, now up to 125 mph, and the hurricane center predicts Laura will come ashore as an extremely powerful hurricane with 145 mph winds tonight just east of the Texas-Louisiana border. Forecasters had this sober message for coastal residents near the landfalling storm: “Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 30 miles inland.”

Closer to home, right along the coast, the biggest impact will be storm surge. However, forecasters have backed off their expectations for the Galveston area, slightly, with 2 to 4 feet of surge now anticipated. We still expect low-lying areas on Galveston Island and Bolivar Peninsula to be inundated with water for several hours tonight. Storm surge will get incrementally worse up the Texas coast, and reach its peak east of Laura’s landfall, in Louisiana.

For everyone else, it’s going to be almost all about the wind. Some areas of town are already seeing breezy winds from the northeast, with recent gusts of about 20 mph reported at Hobby Airport. These winds will build this afternoon and evening and likely peak from about 9 pm through 3 am. I anticipate the potential for Tropical Storm-force wind gusts for at least the eastern half of the metro area, with the greatest risk right along the coast. (The National Hurricane Center estimates there is a 6 percent chance of hurricane-force winds in Galveston, and a 21 percent chance in High Island).

This morning I mentioned the widespread outages during Hurricane Rita for the Houston metro area. I think that remains the biggest potential for disruption tonight, and you ought to be prepared for at least a short outage. But quite frankly, the storm is now tracking slightly east of where Hurricane Rita came ashore in 2005, and will be turning away from Houston. Yes, Laura is more powerful, but we are nonetheless getting further from its core of stronger winds. This eastward movement may also spare Beaumont and Port Arthur from the storm’s very worst effects, but it is still going to be most dicey. We hope to have better information on this later today.

In terms of rainfall we have no real concerns. There may be some briefly heavy downpours, but the region’s bayous are dry. Accumulations of less than 1 inch are likely west of Interstate 45, with 1 to 4 inches possible on the east side of town, increasing as one nears Beaumont.

Rains and winds from Laura should be rapidly moving away from the Houston area by Thursday morning. Rain chances will linger through the remainder of the week, but it really should be nothing to worry about.

Our next update will come no later than 2:30pm CT.

 

 

POSTED AT 6:50 AM CT WEDNESDAY: Good morning. Hurricane Laura has really intensified overnight, and at sunrise this morning it is a Category 3 hurricane with 115 mph winds. It may peak at 130 mph later today before landfall tonight.

Houston now lies well out of the National Hurricane Center forecast cone (see map below) and it is now clear the Houston-Galveston metro area will escape the worst of what is a powerful Hurricane Laura. We are still going to monitor this storm closely, and we will definitely see some inclement weather in our region later today and tonight—but nothing like the Beaumont, Port Arthur, and Southwestern Louisiana areas will experience as Laura makes landfall near the border between Texas and Louisiana around midnight. This has been a very, very close call for Houston.

Hurricane Rita

It seems increasingly evident that Hurricane Rita will offer a useful guide for what to expect from Laura. Rita made landfall just east of the Texas-Louisiana border on September 24, 2005, as a Category 3 hurricane with 115-mph winds. This is near the expected landfall strength of Laura (present forecast is 120 or 130 mph). It looks like Laura may track slightly east of Rita’s path inland, but the 15-year-old storm provides a strikingly similar analog.

So what were the effects of Rita in Houston? This National Weather Service report provides information on wind gusts and rainfall totals from across the region. Winds were the most striking effect. Peak gusts just above 60 mph were recorded at Bush Intercontinental Airport and Galveston Island, with sustained winds of 45 mph. Most of the region briefly saw gusts in the 50s. This was enough to knock out some power on Galveston Island. So I think for Houston, tonight, we should expect to see downed trees and sporadic to widespread power outages. Damages from Rita were estimated at $90 million in Harris County, most due to food losses during outages.

Conditions today and tonight

Now that we finally have a solid handle on Laura’s track and intensity, we can speak with some reasonable confidence about weather as the storm makes landfall around midnight tonight, or shortly thereafter.

Winds

Areas east of Interstate 45 in Houston have about a 50 percent chance of seeing tropical storm-force winds, likely beginning around sunset or a few hours afterward. Areas such as Galveston Bay, Chambers County, and Bolivar Peninsula will see higher gusts. This forecast map, from the European model, provides a reasonable estimate of “peak” wind gusts that can be expected tonight at a level of 30 feet off the ground. Winds at the surface will be about 10 percent less. Under this forecast, Beaumont and Port Arthur would likely miss the storm’s most catastrophic winds, but it’s still going to be nasty, and at this point it’s too close to call. A destructive wind path will continue well inland along Laura’s track.

Storm surge

Surge is another major concern as Laura grows larger and more powerful over the Northwest Gulf of Mexico. The following map from the National Hurricane Center estimates the level water could reach above normal levels at high tide.

Rainfall

Scattered showers and thunderstorms will likely move into the area from the southeast this morning, and will then spread over the region later today and tonight. Here is the latest estimate for rainfall totals over the next 48 hours.

Note to readers

We have received so many kind e-mails, comments here, on Facebook, on Twitter and elsewhere that Matt and I cannot reply to them all, at least not in the midst of a frenetic forecasting period like this. But know that we do deeply appreciate you, our readers. Thanks to word of mouth, almost exclusively, we have grown rapidly since starting Space City Weather in late 2015. On Wednesday, alone, we had 1.6 million page views and more than 520,000 visitors to the site. This is more than Matt and I could have hoped, and we are humbled by your appreciation. Really, we are just two nerds with a passion for weather. We’re glad to be able to share that with you, and help in times of crisis, with the support of Reliant. Our philosophy will never change—we’re just trying to make the best possible forecasts amidst the uncertainty. We love the Houston region, warts and all, and it is our pleasure to be able to give something back.

Our next post will come at 10:30am CT.

 

POSTED AT 2:25 PM CT TUESDAY: Ok, everybody. We understand. You’re sick of reading about Hurricane Laura, and trust us, we’re tired of writing about it. (We first mentioned the possibility of Marco and Laura way back on August 16, which seems like several lifetimes ago). So this afternoon, if I can offer one piece of good news, it’s this: Forecast models are starting to cluster a bit more, so confidence in the track is increasing. By tomorrow morning we should probably have it pretty well nailed down. And then by Thursday afternoon it should be all over as Laura pulls away. So in two days we’ll either be starting the clean-up process, or looking to help our friends to the east, in the Beaumont area and Southwestern Louisiana. The unnerving uncertainty, at least, will end.

Track

We’ve had a new suite of model guidance come in today, and the big news is that the operational run of the European model has shifted east a bit, bringing it closer in line with the GFS global model, as well as the National Hurricane Center forecast. This is the kind of clustering we would hope to see at this point to increase confidence in a track forecast. Under this scenario, Laura would make landfall near the Texas-Louisiana border, or 10-20 miles west of there, late Wednesday or early Thursday. Along this track, Houston would very narrowly escape the worst of Laura’s winds, waves, and rains—these would impact Beaumont, Port Arthur, and Southwestern Louisiana. This means the most likely scenario is now an event similar to Hurricane Rita, in 2005.

However, and this is very important, this track is far from dialed in. There are still some models that dissent from this scenario, and there remains the potential for Laura to wobble as it moves across the Gulf of Mexico. I think we can safely rule out a landfall near Freeport or the San Luis Pass, which would be the absolute worst case scenario for Houston and Galveston. However, a landfall anywhere from the East End of Galveston Island to the Texas-Louisiana border remains in play. Believe me, I would love nothing more than to close the book on Laura, but we are just not there yet. Maybe by tomorrow morning, maybe not. This is a nail-biter for the Houston and Galveston areas. Please heed mandatory evacuation orders and continue preparations.

Intensity

This remains a very difficult forecast. We have seen little strengthening of Laura through the early afternoon hours, but that’s to be expected. The National Hurricane Center anticipates the storm will undergo most intensification between this evening and Thursday morning. They’re predicting Laura will come ashore as Category 3 hurricane, and that seems reasonable, plus or minus a Category. Strong winds will likely begin reaching the coast by around 6pm CT Wednesday.

Laura should be a large and powerful hurricane at landfall, and it will cause widespread damage. Given the potential for further, modest swings in the track, we’re asking you to hang with us for another day or so. We’ve just really got to keep tabs on this one, Houston.

Matt will have our next update at 8:30 pm CT, or a bit earlier.

POSTED AT 10:30 AM CT TUESDAY: In its 10 am update, the National Hurricane Center has modified its forecast track for Hurricane Laura, and has shifted the storm’s landfall slightly closer to the Houston-Galveston metro area. We remain within the cone of uncertainty, and need to be prepared for the possibility of additional westward shifts in the track this afternoon. We are still in line for anything from a glancing blow to direct major hurricane landfall. Bottom line: This is time for preparedness and action, not panic. This is a very serious situation that all residents should be following closely.

Local effects

The location and intensity will play a major role in the effects Houston sees. Even a track movement of 20 or 30 miles can make a big difference in the effects we see (I discussed this in a post earlier today). Due to the uncertainty, for the discussion below we will provide a forecast for Laura’s effects in Houston based on the current National Hurricane Center track, and those for a reasonable worst-case scenario should Laura track further west and make landfall along Galveston Island.

Winds

At this time winds are our greatest concern. They are likely to be strongest near the storm’s center of circulation, and to its immediate east. The most recent run of the HWRF model depicts a probable wind scenario for Laura should the storm make landfall near the Texas-Louisiana border. As you can see, winds over the Houston area would generally remain near or below Tropical Storm intensity, especially west of Interstate 45.

If the storm makes landfall over Galveston Island, the core of strongest winds would go inland along Interstate 45. This would provide widespread residential damage and knock power out for weeks, for many.

Storm Surge

This is our next biggest concern for the metro area. Laura is smaller than Hurricane Ike, and probably will come in east of its landfall location, so a surge along Galveston Island, and along the bay, probably will be less than the region experienced in 2008 under most scenarios. Here is the hurricane center forecast for surge along the current forecast track:

If the storm tracks further west, it looks like a storm surge of 6 to 10 feet along Galveston and Galveston Bay would be a reasonable estimate.

Inland rainfall

This is a much lower priority due to Laura’s forward speed. As I hope you understand by now, this will not be another Hurricane Harvey. In terms of rainfall, we can probably expect 1 to 3 inches with the current track. Should Laura make landfall further down the coast, we can probably anticipate widespread totals of 6 to 10 inches, with higher isolated amounts.

Should you evacuate?

If you live along the immediate coast and are under a mandatory evacuation order, as Galveston Island is, the answer is yes. You should heed local officials who are making difficult calls.

After that, it’s really a personal decision for you and your family. How high is your risk tolerance? Are you willing to spend several very intense, and yes, scary hours in the middle of a hurricane? Do you have a safe place in your home to shelter within? Can you survive without power for several days? The age-old advice during a hurricane is that you evacuate from a storm surge, but take shelter in your home from wind. Effectively, for the Houston area, this means the closer you are to the coast, the higher your risk for surge. These “zip zone” maps (click here to download medium, and large-sized maps) show the risk in this area by zip codes.

All evacuations should be completed by Wednesday, at noon. This is about the earliest reasonable times that winds would arrive in the Houston metro area.

We will update again by 2:30pm CT.