Dramatic image shows where Hurricane Irma may be headed
THE dramatic image that has become our gauge for where Hurricane Irma will next wreak havoc has a potentially fatal flaw, according to meteorologists.
The "cone of uncertainty", as it is known, shows the most likely path for the storm and has been a reference point for days, as the hurricane left a trail of destruction through the Caribbean and bore down on Florida.
With Irma now lashing the state's south-west with sustained winds of 177km/h, and threatening tornadoes and a deadly storm surge on the east coast, weather forecasters have begun to notice a serious problem in how Americans are interpreting the cone.
"Once again I feel #Irma highlighting public misunderstanding what 'cone' is conveying and our difficulty communicating the uncertainty," tweeted Weather Channel host and former NASA scientist Dr Marshall Shepherd.
Some 116,000 people have taken refuge in shelters as the Category 2 hurricane flooded Miami streets and plunged three million properties into darkness. But there are fears Fort Myers and Tampa are unprepared for the "dangerous" and "life-threatening" effects of the storm, which is expected to inundate Florida Keys with a surge of up to three metres.
A storm surge warning has been issued for much of the Florida Peninsula and extended into southern Carolina.
The National Weather Service for Tampa Bay said it had received many questions on social media about what the cone represents.
"It does NOT represent the size of the storm!" the meteorology service warned, explaining that the tropical system only falls within the cone two-thirds of the time.
The Tampa Bay area has not been hit by a major hurricane since 1921.
The cone is an amalgamation of possible paths for the centre of a hurricane over the next three to five days. But that explanation may not be reaching everyone, and it seems some households are risking their safety by not evacuating or shoring up their homes, out of a misguided belief they are out of range.
When Miami chief meteorologist John Morales tweeted that the cone would miss the southern tip of Florida and the Upper Keys, he received some worrying replies asking whether Miami would feel stronger winds than usual.
In fact, people living hundreds of kilometres outside of the cone will feel Irma's wrath, with hurricane-force winds extending 200km in diameter.
Looking at a different chart, showing wind gusts, helps illustrate just how widely the devastation could spread.
Floria Senator Marco Rubio also weighed into the conversation, begging people in south-east Florida to "please understand what #Hurricane "cone" is. It is a projection of the CENTER of #HurricaneIrma not of storm impact."
He also provided another map, to make the deadly situation clear.
Irma is not even guaranteed to follow the broad path of the cone, and has already deviated by shifting west instead of moving straight through Florida's centre.
Central Florida has still been warned to prepare for damaging tropical storm-force winds, as the National Ocean Service station in Key West recorded hurricane-force wind gusts of up to 145km/h.
Federal Emergency Management Agency chief Brock Long warned that those who decided to stay in Key West "were on their own".
The National Hurricane Centre said the storm would bring "life-threatening wind impacts to much of Florida regardless of the exact track of the centre."
More than 6.5 million people in the state are in an evacuation zone, but it is unclear how many have taken their lives in their hands and stayed put.