NHC graphical outlook and the potential track area of invest 91L
A lot has been made already about the presence of invest area 91L. After all, it is hurricane season and we do have an area of interest to monitor in a region that hasn’t had much activity over the past few years. In fact, a grand total of zero hurricanes have made landfall in Texas since 2008 – Ike was the last. While there is nothing at all to suggest that 91L will become a hurricane, it does raise a few eyebrows and for good reason: the rain threat.
May was an absolutely stunning month for rain in parts of Texas. Houston alone set records and had flooding issues. Farther inland, areas such as Austin, San Antonio and Wimberley experienced flooding which resulted in loss of life and significant damage. The power of water is often unappreciated until it changes lives and alters the landscape.
Enter 91L in to the picture and the NHC’s potential track area as seen in the graphic and you can see why Texans are probably a little more concerned about this system than they might be otherwise. None of the intensity guidance suggests anything more than a lopsided, weak tropical storm. Nothing to worry about, right? Wrong. Tropical cyclones, this includes tropical depressions and tropical storms mind you, have four main hazards that they can hit you with: wind, storm surge, rain and tornadoes (downburst winds too). The majority of the public responds well when the forecast suggests 150 mph winds are coming. Sadly, storm surge, as lethal as it is, seems to be ignored (see Katrina, Ike and Sandy).
That leaves us with rain, the most abundant of the tropical cyclone hazards and yet it is the most ignored and least understood by the average person. We think of rain as cleansing and necessary to sustain life. However, too much of it at once or even over several days has a drastic effect on life as we know it.
Only a few inches of rain in a short period of time can overwhelm flood control systems in large metro areas such as Houston. If the rain keeps coming, everything literally cascades in to a total disaster, often stranding hundreds of people who didn’t seem to know better. Even after years of “turn around, don’t drown” people will think they are immune to the laws of physics and do something that defies logic. All because they didn’t respect the power of rain and freshwater flooding.
What does all of this have to do with 91L? Plenty. I think this is an opportunity for people in the region, mainly Texas, to show that they have learned from past experiences. Allison in 2001 was quite a while ago, I’ll give them that. But the May floods were, well, in May – just a few short weeks ago.
There is the potential for what ever becomes of 91L, whether or not it attains tropical storm intensity, to drop a lot of rain over areas that simply don’t need it – at least not in the quantities that some forecasts are showing.
The good news is that upper level winds should keep 91L from becoming much more than a rain threat. This will minimize the amount of wind and surge impact to the coast. However, any onshore flow in areas such as Bolivar Peninsula could lead to over wash – that area is flat with little to no dune protection.
The bad news is that the Gulf of Mexico is ripe with moisture. Water temps are running above normal with actual temps close to the upper 80s along parts of the northwest Gulf. This will lead to an incredible amount of precipitable water being lifted in to the atmosphere and wrung out over Texas next week. Flooding is almost a certainty but exactly where is impossible to pinpoint.
It is going to be important for people in the region to monitor their local news outlets and reliable social media sources for updates. This is going to be a constantly changing situation and a lot will come down to how much rain falls over a certain area and for how long. Since that cannot be forecast with any real accuracy this far out, keeping up with the latest from the National Weather Service and your local TV meteorologists will be important in keeping you and your family safe.
I highly recommend using weather.gov and then inputting your ZIP Code. The return page will have a ton of useful links and information, including the latest watch/warning package and any special statements. It’s all right there at your fingertips – use it!
TS Carlos tracking map from the National Hurricane Center
Meanwhile, Carlos is a tropical storm now just off the coast of Mexico in the eastern Pacific. The forecast takes the storm inland between Tuesday and Wednesday while strengthening it again to hurricane strength. Again, as with 91L in the Gulf of Mexico, the biggest issue with Carlos will be the potential for flooding rain. Certainly hurricane force winds are an issue but with a slow moving tropical system the rain is probably the larger concern at this point. Fortunately, the proximity of Carlos to land should keep it from intensifying much more than it is now, fluctuating back and forth between tropical storm and hurricane strength. Once inland in a few days, its moisture will spread over the interior portions of Mexico further extending the rain and flooding threat to that region.
I will have continuing coverage of 91L and Carlos tomorrow and via my video blog discussions now available through our YouTube channel. Follow and subscribe to the channel here: HurricaneTrack YouTube channel
M. Sudduth 12:15 PM ET June 14