At a Glance

You may think of wind when someone mentions hurricanes or tropical storms.But since 2015, more U.S. hurricane and tropical storm strikes have been notable for rainfall flooding.Two other major summer floods since 2015 weren't from named storms at all.

A hurricane's maximum winds often get the most attention: Most people want to know what category a storm is and is forecast to be on the .

But it's , not wind, that claims the most lives from U.S. tropical systems, and recent notable strikes show how storms are becoming more known for rainfall flooding than damaging winds or even storm surge.

The past two hurricane seasons alone produced the nation's –Hurricanes Harvey (2017) and Florence (2018), part of a greater trend.

One recent study found by as much as 30 percent compared to similar storms in the mid-20th century.

That's important, because how much rain a tropical depression, storm or hurricane produces has little to do with the system's maximum winds. Instead, the slower the system moves, the greater the potential for heavy rain.

Other studies found record-smashing rain in both and was accentuated by climate change.

Overall, over much of the U.S. since the 1950s, according to the 2014 National Climate Assessment. As greenhouse gases trap more heat and warm the planet, both evaporation and precipitation increase.

So, let's look at all of the notable U.S. hurricanes and tropical storms since the mid-2010s to show how rainfall flooding has become such a significant impact.

2018

Hurricane Florence

-Obliterated state tropical cyclone rain records in both .

-Triggered riverine flooding in southern North Carolina and northeast South Carolina that topped records from Hurricanes Matthew (2016) and Floyd (1999) and lingered for weeks in some areas.

-Estimated total damage: $24.2 billion, according to NOAA.

Rainfall totals from Hurricane Florence from Sep. 13-17, 2018.

(Data: NOAA/WPC)

Hurricane Lane

-, with one Big Island location tallying just over 52 inches. Significant flooding inundated Hilo with water several feet deep.

-Wrung out up to 2 feet of rain over parts of .

A car is stuck partially submerged in floodwaters from Hurricane Lane rainfall on the Big Island on August 23, 2018 in Hilo, Hawaii.

(Mario Tama/Getty Images)

Other Notables:

most devastating impacts, storm surge and high winds, hit hardest along the Florida Panhandle Gulf Coast at Mexico Beach and along an inland swath of damaging winds that extended all the way into Georgia, but Michael also produced significant flash flooding in parts of .

Just two weeks after Lane's deluge, Olivia became the , dumping up to in parts of storm-fatigued Hawaii.

2017

Hurricane Harvey

-The nation's wettest tropical cyclone on record, Harvey meandered for five days after landfall.

-At least 20 inches of rain fell over east Texas and southwest Louisiana, an area of almost 29,000 square miles, slightly smaller than South Carolina.

-Two locations (Nederland and Groves, Texas) measured just over 60 inches of rain, a U.S. record for any tropical cyclone.

-Made a devastating Category 4 landfall along the Texas coastal bend north of Corpus Christi.

-Deadliest Texas tropical cyclone since 1919 (at least 68 killed).

-Estimated total damage: $128.8 billion, according to NOAA.

A boat sits near flooded homes in the aftermath of Tropical Storm Harvey in Beaumont, Texas, Thursday, Aug. 31, 2017.

(AP Photo/Gerald Herbert)

Hurricane Maria

-The strongest hurricane to landfall in Puerto Rico since 1928, striking the island at Category 4 intensity.

-Flooding triggered hundreds, if not thousands, of landslides on the mountainous island, wiping out countless trees, roads, bridges and some homes. Even homes that weren't swept down hillsides were isolated by washed-out or tree-blocked roads.

- on Puerto Rico ranged from 5 to almost 38 inches.

-Estimated total damage: $92.7 billion, according to NOAA.

USGS

Other Notable:

While will be remembered most for its destructive strikes on Barbuda, the U.S. Virgin Islands and Florida, it also triggered a combination of storm surge and rainfall flooding in both and .

2016

Hurricane Matthew

-Brought widespread flash flooding and record river flooding to eastern North Carolina, where hourly rainfall estimates from radar were as high as 7 inches per hour.

-100,000 homes, businesses and other structures were damaged by flooding in eastern North Carolina, according to .

-Sections of Interstates 40 and 95 were flooded in the Tar Heel State.

-Estimated total damage: $10.7 billion, according to NOAA.

A truck drives through floodwaters from Hurricane Matthew in Lumberton, N.C., Wednesday, Oct. 12, 2016. People were ordered to evacuate, and officials warned that some communities could be cut off by washed out roads or bridge closures.

(AP Photo/Chuck Burton)

Unnamed, But Major Impact

There have also been a pair of events during recent hurricane seasons that, while not earning status as a named storm or even a tropical depression, were major, historic flood events.

In , a sluggishly-moving low-pressure system resembling an inland tropical depression dumped up to 31 inches of rain in southern Louisiana, more than any tropical cyclone or remnant in the Pelican State since 1950, according to NOAA/WPC forecaster, David Roth.

Record river crests were set in 11 different locations in southeast Louisiana, some 6 feet or more above their previous record.

Infrared satellite image on Oct. 3, 2015, showing an intense area of rainfall (dark and red shadings) extending from South Carolina to off the Southeast coast. Hurricane Joaquin is also shown at peak intensity near the Bahamas.

(NASA via Stu Ostro)

The flood damaged or destroyed over 50,000 homes, 100,000 vehicles and 20,000 businesses, according to . This "no-name" storm was the most destructive U.S. weather disaster of 2015.

Then, in early October 2015, Hurricane Joaquin hammered the central Bahamas.

But a weird swirling upper-level low tapped moisture from Joaquin and piped it into South Carolina for several days, dumping over 20 inches of rain in parts of the Palmetto State, triggering catastrophic flooding there.

Countless water rescues were conducted, and occurred in Columbia. Economists at the University of South Carolina estimated $12 billion in damage and lost productivity, according to The State newspaper.

Major roads, such as stretches of Interstate 95, were closed for weeks until rivers finally receded.