Hurricane Irma is an “extremely dangerous” Category 5, barreling toward the northern Lesser Antilles and southern Florida. It's already the strongest hurricane ever recorded outside the Caribbean and the Gulf of Mexico, and it's likely to make landfall somewhere in Florida over the weekend.

If it does, the impact could be catastrophic.

The storm is life-threatening for the United States, including Puerto Rico, the US and British Virgin Islands, the Dominican Republic, Haiti, Cuba and the south eastern Bahamas. Hurricane warnings have been issued for the northern Leeward Islands, Virgin Islands, Puerto Rico, the Dominican Republic and the Turks and Caicos. A hurricane watch covers Haiti and the south eastern Bahamas.

With maximum winds of 185mph, Irma is tied for the second strongest storm ever observed in the Atlantic.

The hurricane is expected to remain at least a Category 4 for the next few days with minor fluctuations in intensity. It could even become slightly stronger, but has neared the theoretical limit for how strong it can get given ocean temperatures.

It cannot be overstated that Hurricane Irma is extremely dangerous and will produce the full gamut of hurricane hazards across the Caribbean and potentially in South Florida, including a devastating storm surge, destructive winds and dangerous flash flooding.

All of Florida - especially south Florida and the Keys - should be preparing for a major hurricane landfall on Sunday. Tropical-storm-force winds are expected to arrive as soon as Friday.

Computer models are in strong agreement that by Saturday, Irma will be approaching the Florida Keys - where dangerous storm conditions are likely. Then, they show a sharp northward turn by Sunday morning. The precise timing and location of the turn has huge implications for Florida.

It is impossible to say with certainty whether Irma will track up along the eastern side of the Florida peninsula, the western side, or straight up the peninsula. Since the weekend, models have generally shifted westward with the storm's forecast track, which means interests along the coast of the Gulf of Mexico should also closely monitor this storm.

For a major hurricane, the exact track of the storm's eyewall - the zone surrounding its calm centre - is critical as it will determine where the most severe effects tend to concentrate. The most violent winds coincide with the eyewall, and the biggest storm surge occurs just to its right (or north).

But as Irma is such a large and powerful hurricane, very dangerous weather will also occur up to 200 miles away from the eyewall - including coastal surge, flooding rains and potentially damaging winds.

“The hurricane force winds in Irma are wider than Florida,” tweeted Bryan Norcross, hurricane specialist at the Weather Channel. “You won't need a direct hit to get Wilma-type winds & storm surge on both coasts.”

Beyond the weekend, the scenarios really depend on which side of Florida it tracks. But for now, it's safe to say that the southeast United States, including the Florida panhandle, Georgia and the Carolinas, should also brace for potential impacts, such as flash flooding, storm surge and strong winds.

At 5pm on Tuesday, the powerhouse storm was positioned 130 miles east of the island of Antigua in the northern Leewards, where it is forecast to make a direct impact early Wednesday. The storm was moving westward at 15 miles per hour and the Hurricane Center warned weather conditions would soon deteriorate.

Destructive winds as well as heavy rain (8 to 12 inches with isolated amounts of 20 inches) that can produce flash flooding and mudslides are possible in the warning areas. Along the coast, the storm surge height - or rise in water above normally dry air - could reach 7-11 feet - especially just north of the storm centre.

Irma is likely to become the strongest hurricane on record to hit the Leeward Islands, even more intense than David, which raked across the central Leeward Islands in 1979. “David was a horrible hurricane for Leeward Islands: 56 fatalities in Dominica,” tweeted Phil Klotzbach, hurricane expert at Colorado State University.

Antigua, Barbuda, Saint Kitts and Anguilla - in particular - are right in the path of the storm.

“Really feel for the northern Leeward Islands,” tweeted National Hurricane Center forecaster Eric Blake. “A hurricane this strong there only comes around once a generation or two.”

Areas affected by the core winds near the storm's eye face devastating wind destruction. The Hurricane Center provides this description of the damage inflicted by Category 5 winds:

“A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

After passing the northern Leeward Islands, the hurricane will strike the British Virgin Islands with potentially catastrophic effects.“

The US Virgin Islands and Puerto Rico may remain south of the storm's centre, so less prone to Irma's most hostile conditions. But even so, damaging winds and torrential rains are likely along with a significant storm surge at the coast.

Irma's peak intensity so far ranks among the strongest in recorded history, exceeding the likes of Katrina, Andrew and Camille - whose winds peaked at 175 mph.

Among the most intense storms on record, it only trails Hurricane Allen in 1980 which had winds of 190 miles per hour. It is tied for second most intense with Hurricane Wilma in 2005, Hurricane Gilbert in 1988 and the 1935 Florida Keys hurricane.

The aftermath of Hurricane Harvey Show all 19 1 /19 The aftermath of Hurricane Harvey The aftermath of Hurricane Harvey A tattered U.S. flag damaged in Hurricane Harvey, flies in Conroe, Texas Reuters The aftermath of Hurricane Harvey Lisa Rehr holds her four-year old son Maximus, after they lost their home to Hurricane Harvey, as they await to be evacuated with their belongings from Rockport, Texas Reuters The aftermath of Hurricane Harvey People line up for food as others rest at the George R. Brown Convention Center AP Photo/LM Otero The aftermath of Hurricane Harvey Volunteers with The American Red Cross register evacuees at the George R. Brown Convention Center Reuters/Nick Oxford The aftermath of Hurricane Harvey Soldiers with the Texas Army National Guard help the residents of Cyprus Creek Reuters The aftermath of Hurricane Harvey Residents wade through floodwater Reuters/Nick Oxford The aftermath of Hurricane Harvey Residents walk along the flooded roadway of Texas 249 as they evacuate their adjacent neighborhoods EPA The aftermath of Hurricane Harvey A man floats past a truck submerged on a freeway flooded by Tropical Storm Harvey on Sunday AP The aftermath of Hurricane Harvey People are rescued by airboat as they evacuate from flood waters from Hurricane Harvey in Dickinson, Texas Reuters The aftermath of Hurricane Harvey James Archiable carries his bike through the flooded intersection at Taylor and Usenet near downtown Houston, Texas EPA The aftermath of Hurricane Harvey A massive sinkhole opened up on a motorway in Rosenburg, a city 25 miles southwest of Houston, Texas Rosenberg Police The aftermath of Hurricane Harvey People are rescued from flood waters from Hurricane Harvey in an armored police mine-resistant ambush protected vehicle in Dickinson, Texas Reuters The aftermath of Hurricane Harvey People are rescued from flood waters from Hurricane Harvey on a boat in Dickinson, Texas Reuters The aftermath of Hurricane Harvey Evacuees are airlifted in a US Coast Guard helicopter after flooding due to Hurricane Harvey inundated neighborhoods in Houston, Texas Reuters The aftermath of Hurricane Harvey Evacuees leave a US Coast Guard helicopter after being rescued from flooding due to Hurricane Harvey in Houston, Texas Reuters The aftermath of Hurricane Harvey Residents look on at a submerged motorway during a break in the rain in Houston, Texas EPA The aftermath of Hurricane Harvey People photograph the submerged motorway interchange EPA The aftermath of Hurricane Harvey Debris lies on the ground after a building was destroyed by Hurricane Harvey in Aransas Pass, Texas AP The aftermath of Hurricane Harvey Dominic Dominguez searches for his boat in a boat storage facility that was heavily damaged by Hurricane Harvey near Rockport, Texas EPA

If Irma makes landfall as a Category 4 or higher in the United States, joining Hurricane Harvey, it will become the first time two storms so strong struck the United States in the same season.

While all attention is on Hurricane Irma, Tropical Storm Jose formed in the eastern Atlantic Tuesday morning. This storm is also predicted to intensify into a hurricane over the coming days, but the latest track forecast keeps it away from land areas for the most part.