Harvey has undergone some very big changes from last night. It entered a phase of rapid intensification and is now a hurricane and is expected to continue strengthening. It is now forecast to be a category 3 storm at landfall. It very well may be the first first Major Hurricane (Major is defined as a Category 3 or higher) to make landfall in the US since 2005.
Track – Generally the track remains unchanged. It is still forecast to hit between Corpus and Matagorda early Saturday morning. The effects for that area from wind, storm surge, and rain are unfortunately likely to be devastating.
Wind – For our purposes in Houston wind still a relatively minor concern compared to the rain. With the storm now being stronger tropical storm force winds may get a bit closer to us and we may some 40-50 mph gusts in the stronger rain bands that pass through really starting Saturday or Sunday. This could change with Harvey rapidly intensifying and growing, but right now this is my opinion on wind (with one caveat below).
Rain – Rain still looks to start Friday night/Saturday morning, but heaviest may now not come until late Sunday or into Monday and last potentially into Wednesday. Models are still showing widespread 10-15 inches with spots over 20 inches, making the flooding outlook unchanged. Unfortunately, the spots that get higher amounts will be nearly impossible to determine until it starts happening so it is best to prepare as though you will be in one of those spots. Another one of my concerns is that if it tracks a bit closer to here or bounces offshore (see next paragraph) it could be pushing water from the gulf into the bay which would hinder bayou drainage. It will not rain non-stop for this entire time, rather it will come in waves. So just because it stops for a little while does not necessarily mean its done.
Tornadoes – I know this can be a scary topic but often land-falling hurricanes spawn tornadoes on their northeast side, which is where we will be. These tornadoes are typically fairly small, but they could still be enough to break tree branches and toss around loose items outside. Just be sure you have a way to get a tornado warning in the event it happens.
What happens after Harvey makes landfall- This is the million-dollar question and the hardest to answer. The models have shown a couple of different scenarios with what happens between Sunday and Thursday of next week.
Scenario 1: A majority of the models have Harvey making landfall, and sitting just inland of its landfall point until about Tuesday. It then begins moving northeast in our general direction. And there the models diverge a bit again. Lets call them Scenario 1(a) and Scenario 1(b). In Scenario 1(a) Harvey roughly follows HWY 59 northeast up to our area getting here by late Wednesday/early Thursday and eventually away from here by Thursday afternoon. Scenario 1(b) has it drifting back offshore, re-strengthening to tropical storm or minimal hurricane force and riding the up the coastline. Both of these scenarios will bring us lots of rain until the center is east of us, but obviously it moving back over water is the worst one of the two.
Scenario 2: A smaller number of models have Harvey remaining largely in the same spot after making landfall and slowly degenerating and drifting southwest. If this played out the impacts we see will be reduced (it will still rain, but the flooding may not be as severe).
Power – At the moment I do not think power outages will be wide spread. I don’t think we will have those kinds of winds. However, there could be spotty outages due to things like branches blowing into power lines in some of the stronger wind gusts or due to an isolated tornado. Also, if you live in a flood prone area the city has been known to cut the power to areas where home flooding is occurring to prevent fires and electrocution in those homes.
Preparations- As I mentioned yesterday be prepared to remain in one place for at least 2-3 days. Meaning have all of the food, water, medicine and other supplies you could need. Right now it looks like from Saturday afternoon/evening to Tuesday or Wednesday travel will be difficult or impossible. While I do not think power outages will be widespread it would not hurt to at least be prepared for the power to go out with flashlights, batteries, etc. If you have not already, today is a good time to make sure all of the drains in your yard and even on your street are cleared.
The situation will continue to evolve as the storm gets closer so please stay as updated as possible with local media.