Deluge: South Carolina rains came too fast to measure

The biggest weather story nationally continues to be the epic South Carolina floods.

Some quick headlines:

• The death toll continues to rise -- at least 9 dead according to South Carolina Governor Nikki Haley

• Water rescues are still ongoing, with more than 150 rescues so far

• 40,000 residents have no water service and 26,000 power outages are reported

• 550 roads and bridges are closed

• More closures are likely as floodwaters move toward the Atlantic Ocean

• Insurer Aon Benfield says this will easily be a billion dollar-plus natural disaster

More than two feet of rain has fallen in some areas. That's a year's worth of rain for western Minnesota and the Dakotas.

There are many angles to this latest, still-unfolding extreme weather event. The unique meteorology of this event is remarkable. The confluence of a stalled upper level low pressure system, a nearly stationary atmospheric river feeding a tropical moisture plume from Hurricane Joaquin, and a coastal boundary triggering waves of training storms producing extreme rainfall rates.

The extreme rainfall rates generated by the storm are incredible. Rain gauges with 10"+ capacity filled so fast that many NWS CoCoRaHS program observers in South Carolina couldn't get accurate readings as gauges overflowed.

More than a thousand-year rainfall event

Hydrologists will go back and do the math on just how rare this extreme rainfall event is. It's been described as a thousand-year rainfall event, but the reality is that 26-inch rainfall totals in this area are much more rare than that.

Climate change fingerprints

Attribution studies on this latest extreme rainfall and flood event will be done to determine just how much of a climate change fingerprint can be found. One thing is clear already, this event fits perfectly into the growing body of evidence that warmer oceans and a warmer atmosphere are generating more frequent storms capable of producing unprecedented rainfall totals.

Slate's Eric Holthaus adds some interesting perspective.

Sadly, this is exactly the type of event we can expect to see more of as the planet warms. One of the most straightforward responses to climate change is a quickening of the hydrologic cycle: Warmer air speeds evaporation and can cause rain to fall with greater intensity. This supercharges the atmosphere, and boosts the likelihood of devastating floods. What’s less clear is how many of these events it will take—major floods also hit China, France, and Guatemala over the last week, with more than 100 dead—before we start bending the global emissions curve away from a worst-case climate scenario.