Update on Hurricane Laura. It's a mixture of good and bad news. Okay, the good news first. After the models all worryingly trending west for a time placing Houston under the gun, the classic 'wind-shield wiper' pattern of hurricane forecast tracks re-asserted itself and the models swung back towards the east again. Now with less than 24 hours to landfall the track appears to be zeroed in on Port Arthur on the TX/LA border. With the time remaining the closest Laura could likely get to hitting Houston is around the upper Bolivar Peninsula. Bolivar Peninsula was a spit of land with a small town that was wiped off the map back in 2008 by the Category 2 Hurricane Ike, and which never really recovered. Even though both Bolivar and Galveston will feel effects from the hurricane, they'll be on the weaker side where the wind whips round to push water out of the bay, so storm surge for that area and Houston is only 3-5 feet. A Houston hit would have been catastrophic, with the environmental damage from all the stored crude oil and chemicals in the bay beyond belief, so it's pretty great that Laura wobbled North. Instead before her sits Jefferson County and the Sabine Nature Reserve, far more sparsely populated.
Okay, here's the bad news.
Laura is now a Major Hurricane, ahead of schedule and more intense than predicted, with a widening wind field. Yesterday she was ragged and having great difficulty in closing up any sort of eye, leaving her vulnerable to dry air. She'd also been battling a colder than expected trough of water left by Marco which did help for a time against her intensification. We've also Marco to than for cutting the notch in the ridge that probably helped steer Laura away from Houston. Unfortunately Marco also cleared the dry air in her path, and upon waking in the morning I found that without much of it in any quantity there was nothing really to inhibit Laura. Back into warmer waters and moister air, this morning she managed to close off her eye, broaden her wind-field and began a process of rapid intensification with a pressure drop of 6-8h mb in less than an hour. The lower the pressure the faster the wind and the greater the storm surge. As of typing she has now reached Category 3 - the predicted Major category. However she's still intensifying and she's still got some amount of time over water, and it's looking increasingly likely that a Category Four is likely.
What is a Category Four? It's anything between 131 and 155mph and with the shallow continental shelf located in this area around 10-15 feet of surge, a surge which in this case will push up to 30 miles inland owing to the many lakes, channels and general bayou nature of the area. Fortunately the coastal area itself is very, very, very sparsely populated. Unfortunately a little way in from the coast sits Sabine Lake and Lake Charles, both connected to the sea. Both have large towns clustered around them at the north end and both are very vulnerable. The ideal result would be for Laura to hit just to the east of Sabine Lake, which would hopefully spare Port Arthur and Beaumont the worst being on the weaker side for surge, and directing the bad surge into the unpopulated Sabine Wildlife Preserve which stretches along a large stretch of coast for a very good reason. Not only is it sparsely populated but marshland and wetlands do a great job of robbing a hurricane's surge of its battering power. Much more to the east however and Laura would badly threaten the small city Lake Charles and its large chemical works. Still further east is Lafayette and Morgan City. A strike here is unlikely, but anything closing towards that direction would be a surge of 8-12 feet in the area, and it's far more populated.
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This is going to landfall in the middle of the night local time. I'm worried the Marco-Debacle combined with Covid19 worries might induce people not to bother evacuating. Now comfortably measuring a category three in pressure drop, this is nothing to take lightly. If this weakens somehow to Category 2 then the above mentioned towns will only get their feet wet. If it sticks in at Category Four...