Floods in the 21st Century: Where Do We Stand?

For many Tennesseans affected by the flood of 2010 the event was a monumental life changer, while for others, a brief moment of inconvenience. Yet many who didn’t lose any physical possessions did lose piece of mind, perhaps a loss of perceived security. Where does this “1000-year flood” rate among other recent US flooding disasters and, perhaps more importantly, is there a link between this super storm and other recent extreme deluges?

What does the term “1000-year” or “100-year flood” mean? In the article “The 100-Year Flood” Karen Dinicola writes “The term “100-year flood” is really a statistical designation, and there is a 1-in-100 chance that a flood this size will happen during any year. Perhaps a better term would be the “1-in-100 chance flood.”

As our mainstream national media continues to minimize, or ignore, many flooding disasters, here is an overview of some recent 1-in-100 to 1-in-1000 chance floods.

In 2006 a massive flooding event affected several Mid-Atlantic States from upstate New York to North Carolina, killing at least 20, and sustaining over $1 billion in damages when 3 to 5 inches of rain fell across several states in just a few hours.

“100 year” floods have occurred in southern New Hampshire in 2005, 2006, and 2007.

In March of 2008 a massive flooding event took place in the Southern Midwest and Southern Plains regions killing at least 17 people. Many areas received 6 inches or more of rain in less than three days.

In June of 2008 the Midwest was devastated by a 500 year event when several weeks of heavy precipitation caused significant flooding, Iowa being exceptionally hard hit. 24 people lost their lives and $15 billion in damage occurred across the region. This was the second “500 year event” to strike this region in 15 years, the first occurring in 1993 when flooding killed 48 people and sustained $30 billion in damage. Iowa and other Midwestern states also endured significant flooding in 2007, and 2009.

In September of 2009, the state of Georgia experienced extreme flooding, when torrential downpours, including 22 inches of rain in Atlanta, resulted in at least 9 deaths, causing an estimated $500 million in damages. 17 counties across the state were deemed Federal Disaster Declarations in this “500 year event”.

In the Northeast in late March of 2010, Rhode Island was devastated by a “100 year flood” rendering thousands homeless, and causing damage in excess of $200 million. It was Rhode Island’s wettest month on record with rainfalls totals of 16.34 inches. This was the third time in 2010 that the Northeast had received significant flooding, each time the result of powerful nor’easter’s dumping between 3 to 8 inches of rain.

Fargo, North Dakota has seen a ten-year flood every year for the past four consecutive years.

On May 1st and 2nd 2010, came the Tennessee flood, one of the most epic extreme weather events ever to occur in the US. With almost no warning, between 12 and 20 inches of rain fell in just 36 hours rendering 46 of Tennessee’s 95 counties federal disaster areas. At least 33 people died across three states, thousands left homeless, and $1.9 billion of damage sustained to the private sector in Nashville alone.

In the weeks following the Tennessee flood, parts of Texas were flooded when they received 11 inches of rain on June 9. At least 20 people were killed in Arkansas on June 11 when rivers rose at a rate of 8 ft per hour and flooded a campground, the result of torrential rains. On June 14, storms dropped about 10 inches of rain in Oklahoma, causing 59 out of 77 counties to be declared a state of emergency. On July 2nd Des Moines’s Iowa received significant flooding, and hardly a day passed in the first 3 weeks of July without some news about localized flooding somewhere in the US.

Kentucky, which already received extensive flooding earlier this year during the Tennessee deluge, was hit with its own deluge on July 21 and 22 when an estimated 6 to 9 inches of rain fell between Tuesday night and Wednesday morning. Over 200 homes were swept off their foundations and Kentucky has been declared a state of emergency by Governor Steve Beshear as this disaster has struck multiple counties.

This year has also brought extreme flooding to other areas around the globe. Just two weeks after the Tennessee disaster, massive flooding occurred in Poland, and they received a second round of significant flooding on the week of June 8. At least 11 people died in southern France on June 16 when heavy rains triggered flash floods, and Spain received significant flooding as well.

At least 155 people  died and 1.3 million evacuated in China as a result of flash flooding from torrential downpours on June 16. This year has brought the worst flooding China has seen in more than a decade as “three quarters of China’s provinces have been plagued by flooding and 25 Rivers has seen record high water levels”. More than 1000 people have died or are missing amidst tens of billions of dollars worth of damage sustained so far.

Although flooding is a natural occurrence, most of these events were caused by either rain storms that were not the result of hurricanes or tropical storms, or uncharacteristic spring melts caused by unprecedented warm weather. Although the survivors of the Tennessee flood, and other 2010 US flooding disasters, might have perceived their local events as isolated cases, perhaps the sheer number of these extreme deluges in recent history might indicate they are part of a growing trend, sharing many commonalities.

In 2009 a report commissioned by the former Bush administration warned of greater incidences of severe weather and heavy rainfall for the US. It predicted that more winter and spring precipitation in the Midwest would lead to increased flooding and that the Southeast would see increases in flooding and severe weather.

Kevin Trenberth from the national Center for atmospheric research stated in a recent interview:

For every one degree Fahrenheit increase in sea temperature, the water holding capacity for the atmosphere goes up by 4%. And since the 1970’s on average there’s about a 4% increase in water vapor over the Atlantic Ocean and when that gets caught into a storm, it invigorates the storm so the storm itself changes, and that can easily double the influence of that water vapor and so you can get up to an 8% increase, straight from the amount of water vapor that’s sort of hanging around in the atmosphere. This is reasonably well established.”

It should also be noted that the past decade was the warmest on record, according to NASA, and this year boasts the hottest January through June on record.

While no one event can be directly tied to climate change, our climate is simply an average of weather over a period of time. With these kinds of super storms now more prevalent, it is essential for all Americans to consider the possibility of manmade climate change to better prepare for our future.

The climate is changing and will continue to change, and so far, the recent changes are not an improvement for life on earth. We must explore ways to avoid the unmitigated catastrophe that awaits us on our current path. Education and awareness is key. It’s time to get vocal about these developing new trends as they are possibly the biggest threats to our national security and life on earth as we know it.

Is the hottest spring on record causing widespread extreme weather?

As a resident of middle Tennessee, the statewide flooding caused by our extreme deluge on May 1 and 2 was a wake-up call. It’s barely been six weeks since that catastrophic event, but during that relatively short time period, I’ve noticed several other significant weather events in the US, and globally.

Just two weeks after the Tennessee disaster, massive flooding occurred in Poland, and they received a second round of significant flooding on the week of June 8. Parts of Texas were flooded when they received 11 inches of rain on June 9. At least 20 people were killed in Arkansas on June 11 when rivers rose at a rate of 8 ft per hour as a result of torrential rains. On June 14, storms dropped about 10 inches of rain in Oklahoma, causing 59 out of 77 counties to be declared a state of emergency. At least 11 people died in southern France on June 16 when heavy rains triggered flash floods, and Spain has had significant flooding as well (to see a stunning slideshow of some of the flooding in Europe follow this link. At least 155 people have died and 1.3 million have evacuated in China as a result of flash flooding from torrential downpours, also On June 16. To my knowledge, none of this flooding was the result of rain storms associated with tropical storms.

On May 26 Colorado received a massive hailstorm that delivered up to 12 inches of baseball sized hail  causing an estimated $70 million worth of damage. Deadly tornadoes ravaged parts of the Midwest on June 7. There have also been tornadoes in the Northeast, an area that almost never experiences this kind of severe weather, and early June has brought a heat wave to parts of the Midsouth.

These are just the anomalies that I happened to notice. This spring/early summer seems to have an exceptionally high concentration of extreme weather events. It seems obvious for there to be a connection between all these weather extremities and the fact that this is the hottest springs on record. If 100 to 1000 year floods are happening daily, or weekly, citizens need to understand the likelihood of this continuing trend, and prepare for these kinds of events. The media has been downplaying most of the extreme weather events in recent history and any potential link to climate change, and it is now time that they step up to the plate and do the right thing.

This is not just another attempt to convince global warming deniers that climate change is real (which obviously it is), or about our need for a new energy policy (which must be addressed as well), it’s also about creating a greater awareness of the current weather trends, and helping to prepare our fellow citizens and infrastructure for this unsettling new reality. This argument about climate change can no longer be between left and right or Democrat and Republican, the climate has changed, and will continue to change. We must come together and accept that fact. The real question now is; How will we deal with this? There is a difference between being an alarmist, and simply being a realist who is prepared. Ignorance is bliss, knowledge is power. I don’t know about you, but I’m into knowledge.

Is weather forecasting less accurate because meteorologists are global warming deniers?

The extreme precipitation event that occurred on the weekend of May 1st, 2010 in middle Tennessee dumped a record rainfall of 12 to 20 inches in 36 hours resulting in widespread flooding that caused several deaths and billions in damages across the state. This event came with very little warning, and while predicting the weather is never an exact science, it is noteworthy to mention that the forecast for the weekend of this flood was similar to the forecast for the preceding weekend, in which much less severe weather was experienced.

On Friday, April 23rd Nashville’s News 2 weather forecast stated the following:

“TONIGHT – strong storms that develop out to our west this afternoon will likely hold together enough to move into middle Tennessee late this evening. We are not expecting severe weather but some of these storms tonight could still have a punch to them in the form for heavy rain, strong winds and frequent lightning…SATURDAY WILL HAVE SEVERE WEATHER – All things in place for a major severe outbreak tomorrow afternoon and evening. Tornadoes are possible as well as damaging winds and heavy rain….The Storm Prediction Center continues to show a very high risk over a very large area in the south tomorrow.”

On Friday, April 30th, the day before the flood began, Nashville’s News 2 weather forecast stated the following:

THIS WEEKEND – For the second weekend in a row severe weather and big rains threaten our Saturday and Sunday. Saturday looks a little more random, likely a big round in the morning then just scattered stuff the rest of the day….By Saturday night another big round moves over bringing slight chances of severe weather and heavy rain. What comes in tomorrow evening will likely be what had developed in the afternoon to our west. A significant severe weather outbreak is expected over the deep south and western Tennessee…Sunday a cold front moves over triggering very heavy rain and a chance of severe weather.  I think Sunday will be a much more widespread heavy rain event. Flash flooding will be a concern. HPC puts the very heavy rain in the western edge of middle Tennessee on Sunday.

Both of these forecasts are somewhat typical to some of the severe weather outbreaks typically experienced in this region during the spring. It is also noteworthy that the weather maps on the News 2 website actually showed a 45% chance of extreme weather on Saturday, April 23, and only a 15% chance of extreme weather for the weekend of May 1st.

These facts raise some important questions. A recent poll revealed that most meteorologists do not believe in man-made global warming. Is weather forecasting becoming less accurate because climate change has not been considered by many meteorologists? Are the forecasting models becoming outdated? Are there any warning signs preceding catastrophic weather events that might be missed because many meteorologists fail to see the big picture? The Tennessee deluge has been called a “500 to 1000 year event.” If meteorologists are not considering climate change a factor in their predictions, does this mean they will discount this storm, and others, as once-in-a-lifetime freak events and fail to see this and similar events as part of a new trend?  Will they remain ignorant to the likelihood of another extreme deluge in the near future?

Because of a conscious concerted effort, the ability to forecast tornadoes has greatly improved in recent years because there was a fundamental need for more accurate storm forecasting. With extreme precipitation events on the rise, perhaps that kind of overhaul now needed in this area as well. Tornadoes and hurricanes often get the press that extreme weather events deserve, yet a flood caused by a rain storm can be just as catastrophic, as the recent events in Tennessee and elsewhere have demonstrated. Perhaps it’s time for the meteorologists to get fully on board with their climatologist counterparts, so future extreme weather forecasting might be more closely aligned with the new reality we are now faced with.