Hurricanes have a mission: to take hot, moisture-loaded (we call it ‘humid’) air north from the tropics toward the poles. Dorian has been a failure at that mission so far because the storm has taken the steamy tropical air borne over bath-water-warm ocean and converted it to rain over the same ocean.
Dorian barely moved for 30 hours between Sunday and Monday. In that time, NASA’s IMERG measured incredible rainfall over the Bahamas underneath the storms’ core around Abaco and Grand Bahama Island.
“In the early hours of Tuesday, September 3, Hurricane Dorian had been stationary over the island of Grand Bahama for 18 hours, most of the time as a category 5 hurricane. Storm-total rain accumulation over parts of Grand Bahama and Abaco Islands have exceeded 24 inches according to NASA satellite-based estimates.”
So how much water are we talking here?
According to the U.S. Geological Survey, ‘One inch of rain falling on 1 acre of ground is equal to about 27,154 gallons and weighs about 113 tons. An inch of snow falling evenly on 1 acre of ground is equivalent to about 2,715 gallons of water.’
So twenty-four inches of rain on a single acre of land in the Bahamas would be an incredible 651,696 gallons of water and would weigh 2,712 tons!
If that fell uniformly on Abaco Island (776 mi²), it would have been 323,658,301,440 (323.7 billion) gallons of water weighing 36.6 trillion tons!
The extreme rainfall and the high winds ‘mixed up’ the Atlantic underneath Dorian causing a significant drop in sea surface temperatures:
Dorian slowed to a crawl over the Bahamas, and that has lead to the steady decline in wind speeds and increase in pressure over the past day and a half. Dorian churned up colder water, choking itself off from the warmer water it needed to maintain itself. pic.twitter.com/GhdoiqN2Q0
— Alex Puckett (@Puckettwx) September 3, 2019
Hurricane Dorian is still expected to be trouble on the East Coast from Florida to North Carolina through Thursday and Friday.
Track the storm here: