“Catastrophic”, “life-threatening”, “devastating”, “uninhabitable”, “unprecedented” and “record-setting” are only some of the menacing words that have been used to describe the tropical storm that hit the United States’ Texan Gulf Coast on Friday, already claiming at least five lives and displacing so many more.
Hurricane Harvey, as its already been named, is a category 4 hurricane and over the past weekend alone, it has caused catastrophic floods and devastation in Houston after “unprecedented” storms and torrential rainfall.
The United States of America, some will say is no stranger to hurricanes -recall the Hurricane Carla (1961), Hurricane Katrina, the Hurricane Joaquin (South Carolina 2015), Hurricane Wilma (2005) and Storm Allison (2001) – and they’ll be right. But this time, it’s so bad the American National Weather Service is reportedly “ratcheting up its language to help people understand that this storm is not a normal event.
Mashable senior editor (climate, science, weather and politics), Andrew Freeman started up a conversation on Twitter on Friday when he asked if anyone could recall a “more dire flood forecast with land falling hurricane in the past few decades” but none of those who responded – including meteorologists – could.
The initial rainfall forecast for the hurricane were upwards of 40 inches and are expected to fall from Corpus Christi area in Texas and North-Eastward to the Houston and Galveston region, and “potentially extending into Louisiana”, Austin and San Antonio”. Over the weekend, Harvey already hit Rockport, Refugio, Victoria, Meyerland in the Houston area. The damage so far is unquantifiable and five people are already dead.
Expected to continue way till the end of this week at least, Hurricane Harvey is already being considered to have its own place in history as one of the most epic distaters to ever hit the United States. The centre of the hurricane, at its start, was moving over Gulf waters that were 1 to 2 degrees Celsius above average for summer time, making it all the more dangerous with several areas expected to experience between 8 inches to 1 foot of storm surge and endless flooding. In the most lay terms, this situation can only be likened to a year’s worth of rainfall happening within a week.
Still, Hal Needham, a scientist and consultant who studies storm surge risk and who spoke with Vox’s Brian Resnick warned that people may still be thinking too simply about this – measuring wind speed, storm surge height, and rainfall – when they should be thinking about all the element working as one huge force.
Needham’s theory is that all that’s been forecast so far means that there’s a risk of a combination of both storm surges and heavy rainfall and that “combination may be conusing to people.”
Needham went on to explain some of the more technical bits of the forecasts thus:
30-or-40-plus inches of rain?
Hal Needham: Let’s put it in context. Much of the Northeast Corridor — Washington to New York and Boston — maybe receives maybe between 40 and 45 inches of rain a year. Think of all the rain you get in July through Christmas and put that in a couple days. It’s a lot of rain.
What’s a storm surge?
Hal Needham: A storm surge is when the onshore winds of the hurricane elevate the level of the ocean. The entire column of water in the ocean is rising, due to onshore winds and lower pressure. We have less pressure pushing down on the surface of the ocean, and the water can actually rise a little. But most of the force creating the surge is the onshore winds. When you hear about a 6-foot storm surge, the sea is actually rising by 6 feet. On top of that, we get large destructive waves.
The biggest concern?
Hal Needham: public awareness and risk perception… [and] just the prolonged nature of it [Harvey], that it’s really going to go into the middle of [this] week. That it’s just going to park, and perhaps we’re going to see many feet of rain. There will be some substantial wind damage along the Central Texas coast, but when we look back on this, in historical context, I think it will really be the flood that’s the main story.
And his fears, we think, may have already come to pass during the weekend considering the amount of flooding we’ve already seen so far.