It was obvious from the start that significant flooding would occur across parts of South Carolina and North Carolina, with or without the help of Hurricane Joaquin. All of the weather models locked on a solution for significant rainfall in this region. Rain fell all weekend long and at times was producing five inches of rain per hour in several spots. Now more than 13 inches (35 cm) of rain has fallen in three days in the historic city of Charleston. For some locations in Central and Eastern South Carolina, this has been a one-in-1,000-years rainfall event.
What does that mean? It means that there is a 0.1% chance to see an event like this to happen in any given year.
It means roads were washed out. About 100 people were rescued from trapped cars on flooded roads. As of Sunday evening, there have been seven deaths (according to Associated Press) due to the onslaught of heavy rain and flooding.
Hundreds of people have lost homes. It could take months for some residents to get back to some kind of normalcy. It is likely that this is one of the worst natural disasters the state of South Carolina has ever seen.
Good news is that the rain should taper off by Monday night.
— Eric Holthaus (@EricHolthaus) October 5, 2015
Heavy rain and flash flooding occurred thanks to an upper level low spinning away in the atmosphere. The low could not move and was forced to sit across Alabama and Georgia. As it did so, it brought a ton of moisture from the Atlantic and pushed it into South Carolina/North Carolina.
The plume of moisture, also called an atmospheric river, continued to push heavy rain over the same areas. The low was not able to move and the rain continued to develop.
Some of the tropical moisture from Hurricane Joaquin was able to travel towards the Southeast too. All of the moisture converged into one spot, and incredible amounts of rain fell.
Check out the three-day rainfall totals across the U.S. Southeast. Some locations recorded nearly two feet of rain during this time period.
— Greg Carbin (@GCarbin) October 4, 2015
Conagree River near Columbia, S.C. just passed into all-time record territory, and it’s still rising. pic.twitter.com/sqNXCazO2f
— Eric Holthaus (@EricHolthaus) October 5, 2015
Cars were found trapped in flood waters, and several swift-water rescues were performed. According to WLTX, South Carolina Governor Nikki Haley said Sunday (October 4, 2015) that hundreds of National Guardsmen and local/state emergency officials have responded to hundreds of rescues, accidents, and calls for assistance.
Several dangers remain within the state. Winds have been strong enough to knock trees over and result in power outages. With so much rain in a short period of time, the ground is saturated, and it does not take 50 mph winds to knock trees over. Many residents are concerned about drinking water, several cities are encouraging people to boil their water before consumption. Heavy rain has washed out roads, bridges, and even train tracks. Columbia mayor Steve Benjamin ordered the city to have a curfew from 6 p.m. EDT Sunday evening until 6 a.m. EDT Monday morning. Several interstates such as I-20 and I-26 were closed, and motorists were forced to turn around.
— Megan Rivers (@MegMRivers) October 4, 2015
— CNN (@CNN) October 5, 2015
We in the United States have seen several historic floods over the past decade. The Boulder, Colorado flood of 2013 peaked at 18 inches of rain. In 2009, the city of Atlanta recorded up to 21 inches of rain. One year later in 2010, Nashville experienced 22 inches of rain. This event maxed out at nearly 24 inches of rain.
— Daniel Bonds (@Daniel_Bonds) October 4, 2015
Charleston broke several records this weekend according to their National Weather Service office:
SEVERAL RAINFALL RECORDS SET AT CHARLESTON INTERNATIONAL AIRPORT AND DOWNTOWN CHARLESTON…
…CHARLESTON AIRPORT RAINFALL RECORDS…
GREATEST 1-DAY RAINFALL…..11.50 INCHES SET ON OCTOBER 3 2015
OLD 1-DAY RAINFALL RECORD…10.52 INCHES SET ON SEPTEMBER 21 1998
GREATEST 2-DAY RAINFALL…..13.11 INCHES SET ON OCTOBER 2-3 2015
OLD 2-DAY RAINFALL RECORD…11.10 INCHES SET ON JUNE 10-11 1973
GREATEST 3-DAY RAINFALL…..14.48 INCHES SET ON OCTOBER 1-3 2015
OLD 3-DAY RAINFALL RECORD…11.95 INCHES SET ON JUNE 9-11 1973
GREATEST MONTHLY OCTOBER RAINFALL..16.61 INCHES THROUGH 9 AM TODAY
OLD MONTHLY OCTOBER RAINFALL…….12.11 INCHES SET IN 1994
…DOWNTOWN CHARLESTON RAINFALL RECORDS…
GREATEST 3-DAY RAINFALL…..13.80 INCHES SET ON OCTOBER 1-3 2015
OLD 3-DAY RAINFALL RECORD…12.39 INCHES SET ON JUNE 9-11 1973
GREATEST MONTHLY OCTOBER RAINFALL..14.25 INCHES THROUGH 430 AM TODAY
OLD MONTHLY OCTOBER RAINFALL…….11.74 INCHES SET IN 1959
We can’t forget Columbia, South Carolina either. Columbia established an all-time record maximum daily rainfall amount for any calendar day at Columbia since precipitation records began on June 1, 1887. The old record was back on July 9, 1959 of 5.79 inches. The new record beat it by nearly an inch at 6.87 inches.
When flash flooding occurs, meteorologists always tell the public:
Turn around, don’t drown.
If you don’t understand why, then simply watch the video below. Good news is that he made it out of the truck.
Bottom line: The flooding that has occurred in South Carolina and parts of North Carolina in October, 2015 will go down in history. Before this storm, several residents would argue that Hurricane Hugo from 1989 was one of the worst storms to impact their state. Now, they put this weekend’s event as number one.
Matt Daniel is Meteorologist for WBRC in Birmingham, Alabama. A self-described "big weather and music geek," Matt has a passion for helping to keep people safe when severe weather strikes and says if you don't have a NOAA Weather Radio ... you should get one.