A meteorologist calculates that Hurricane Irma will dump about 10 trillion gallons (38 trillion litres) of rain on Florida over a day-and-a-half time period. That’s about 500,000 gallons (1.9 million litres) for every Florida resident.
Private meteorologist Ryan Maue of WeatherBell Analytics based his calculations on weather service forecasts. He also calculates it will dump 6 trillion gallons (23 trillion litres) on Georgia.
READ MORE: LIVE UPDATES: Tracking Hurricane Irma’s path
By comparison, Hurricane Harvey, which stalled over the Texas coast, dumped about 20 trillion gallons (76 trillion litres) on Texas and 7 trillion gallons (26 trillion litres) of rain on Louisiana in about five days. One place around Houston got more than 50 inches (130 centimetres) of rain. Irma is expected to crawl steadily through the Sunshine State.
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The National Hurricane Center projects 15 to 20 inches (38 to 50 centimetres) of rain with spots up to 25 inches (64 centimetres) for the Florida Keys. Western Florida is forecast to get 10 to 15 inches of rain (25 to 38 centimetres), with as much as 20 inches (50 centimetres) in spots. The rest of Florida and southeastern Georgia is projected to get 8 to 12 inches (20 to 30 centimetres) of rain, with isolated outbursts up to 16 inches (40 centimetres).
All of southern Florida was feeling the storm’s effects, with at least one man killed, a woman forced to deliver her own baby and trees and apartment towers swaying in high winds.
The National Hurricane Center said the storm had maximum sustained winds of 120 miles per hour (195 kph), dropping it to a Category 3, the midpoint of the five-step Saffir-Simpson scale.
WATCH: Residents capture flooded streets in Miami’s financial district
Irma had been one of the most powerful hurricanes ever seen in the Atlantic, killing 28 people in the Caribbean and pummeling Cuba with 36-foot (11 meter) waves on Sunday. Its core was located about 35 miles (56 km) south of Naples by 2 p.m. ET (1800 GMT).
Some 6.5 million people, about a third of the state’s population, had been ordered to evacuate southern Florida.
Officials warned that Irma’s heavy storm surge – seawater driven on land by high winds – could bring floods of up to 15 feet (4.6 m) along the state’s western Gulf Coast. Small whitecapped waves could be seen in flooded streets between Miami office towers.
WATCH: Global News reporter ventures out into Hurricane Irma to see collapsed crane
“There is a serious threat of significant storm surge flooding along the entire west coast of Florida,” Governor Rick Scott told a press conference. “This is a life-threatening situation.”
Tornadoes were also spotted through the region.
Irma is expected to cause billions of dollars in damage to the third-most-populous U.S. state, a major tourism hub with an economy that generates about 5 percent of U.S. gross domestic product.
About 1.8 million Florida homes and businesses had lost power, according to Florida Power & Light and other utilities.