Forecasters say Hurricane Joaquin has strengthened to 'an extremely dangerous Category 4 hurricane.'

The National Hurricane Center in Miami said Thursday afternoon that additional strengthening is expected over the next 24 hours, as the storm moves past the Bahamas, bringing winds, heavy rain, dangerous surf and significant storm surge.

The storm has maximum sustained winds of 130 mph and is moving southwest at 6 mph. It is about 70 miles south-southeast of San Salvador, Bahamas.

A hurricane watch is in effect for much of the Bahamas and other nearby islands. Forecasters say the center of Joaquin should move over or near portions of the central Bahamas Thursday afternoon and night.

Forecast maps show the storm passing the Bahamas and then making its way toward the U.S. over the next couple of days, though it's currently still unknown where or if the hurricane will make landfall in the United States.

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Hurricane Joaquin was upgraded to an 'extremely dangerous' category 4 storm on Thursday

Forecast maps show the storm passing the Bahamas and then making its way toward the U.S. over the next couple of days, though it's currently still unknown where or if the hurricane will make landfall in the United States. Above, the storm at 9:37am on Thursday

New Jersey Governor Chris Christie, who led his state through the aftermath of Superstorm Sandy in 2012, wasn't taking any chances on Thursday though when he declared a state of emergency in preparation for Joaquin.

At a press conference just before noon, Gov Christie said that it was too soon to know whether Joaquin would be hitting New Jersey, but with unrelated heavy rains forecast to start tonight, he wanted to get the state prepared for the worst.

For New Jersey residents, Christie's call to start preparing for the storm immediately will not doubt be followed closely, the devastation of 2012's Superstorm Sandy still fresh in their minds.

Joaquin is the third hurricane of the 2015 Atlantic season, intensified late Wednesday into a Category 3, on a scale of 1 to 5, with maximum sustained winds of 115 miles per hour. The storm was expected to gain strength and could become a Category 4 over the next day as it moves near or over portions of the Bahamas, the NHC said.

Hurricane Joaquin intensified to a Category 3 storm on Wednesday, but forecasters are still uncertain whether the storm will make landfall on the East Coast or veer off into the Atlantic. Above, each line represents a possible track for the storm, as of Thursday

At a press conference just before noon on Thursday, Gov Christie said that it was too soon to know whether Joaquin would be hitting New Jersey, but that he wanted to get the state prepared for the worst. Christie, who is also campaigning for president, pictured above on Tuesday in Des Moines, Iowa.

In this handout from the National Oceanic and Atmospheric Administration (NOAA), Hurricane Joaquin is seen churning in the Caribbean on September 30

Several models show the hurricane turning north, bringing it to the coast of the Carolinas or mid-Atlantic states on Friday or Saturday, the agency said. However, the storm's exact path remains unclear, with what the NHC called an 'excellent' prediction tool indicating it could cut a path out to sea.

'The range of possible outcomes is still large, and includes the possibility of a major hurricane landfall in the Carolinas,' it said.

The governors of New York and Connecticut and emergency-management officials in New Jersey - states all hard hit by Superstorm Sandy and already facing heavy rains unrelated to Joaquin on Wednesday - warned residents to begin preparations for a possible severe storm.

These states are on edge that Joaquin could turn into a second Sandy, as one forecasting model show the hurricane making landfall in the same area devastated in three years ago.

That new computer model, produced by the Global Forecasting System, predicts that the storm will change course to move north through the Atlantic before veering westwards and hitting the eastern seaboard. If the model is correct, the storm would hit around Monday.

'Our state has seen the damage that extreme weather can cause time and time again,' said New York Governor Andrew Cuomo. 'Take precautions for more heavy storms in the coming days.'

One weather model shows Hurrican Joaquin swining out to sea at some point over the weekend, above

Hurricane Joaquin could then possibly make landfall in New Jersey and New York City on Monday, by hooking back towards the tri-state area

Meanwhile, steady rain drenched much of the East Coast on Wednesday, flooding roads, closing schools and forcing some people from their homes. And forecasters say the worst is yet to come.

The rainstorms will likely soon be joined by Hurricane Joaquin in a powerful weather system that could linger for days and dump as much as 10 inches through early next week in some places.

The deluge has the potential to saturate the ground so heavily that trees topple onto power lines even without heavy winds.

'The bottom line is: We are expecting very heavy rains all the way from the Carolinas up into New England,' said Bruce Terry, lead forecaster for the government's Weather Prediction Center.

Before the hurricane draws close to the U.S., an area of low pressure in the Southeast and a front stalled over the East Coast will pull moisture from the Atlantic Ocean that falls as rain over the next few days, Terry said.

More forecasting models show the hurricane making landfall somewhere between the Carolinas and New Jersey early next week

This model shows the hurricane making landfall in the Virginia and Maryland area. As the storm makes its way north, it will slow down in colder waters

Right now, the storm's direction points directly towards New Jersey, but weather patterns could push it left or right in the coming days

The northeast is already dealing with unrelated rains. The mid-Atlantic state are expecting as much as four to eight inches over the weekend

The darkened space in the middle of this map shows the area where the hurricane is mostly likely to track

The heaviest rain is expected in wide swaths of North Carolina and Virginia, along with parts of Maryland, Delaware and New Jersey, according to a National Weather Service forecast map.

Joaquin could make the difference between a few days of constant rain and an especially damaging storm. But the hurricane's path was far from certain.

'That's still up for grabs,' Terry said.

So far, there's been little consensus among computer-prediction models for the hurricane.

The National Hurricane Center in Miami was to send a plane aloft Wednesday to gather data about Joaquin that will hopefully 'get those models into better agreement,' said Rick Knabb, the center's director.

'We're going to be throwing a lot more aircraft resources at this problem over the next few days.'

Heavy rain caused the flooding of roads, closing of schools and forced some people from their homes on the East Coast Wednesday (New York City skyline pictured above)

The rainstorms may soon be joined by Hurricane Joaquin in a powerful weather system that could linger for days with up to 10 inches of rain (sky behind the Empire State Building on Wednesday in NYC)

The deluge early next week has the potential to saturate the ground so heavily that trees topple onto power lines even without heavy winds (a runner in new Jersey on Wednesday with the NYC skyline behind him)

In southwest Virginia, schools closed early Tuesday in several counties because of flooded roads. Blacksburg had a single-day record of 4.39 inches.

In Salem, 30 members of a water-rescue team removed 100 people from a low-lying apartment complex and trailer park.

To the west in Elliston, 74-year-old Wendell Johns said floodwaters inundated his yard and left behind garbage and mud, but didn't make it into his trailer.

'I've got so much trash washed up, I don't know what I'm going to do,' he said.

With water rising, he went Tuesday to stay at his sister's house after gathering what personal items he could carry, including an oxygen tank to help him breathe.

He said he spent an uneasy night wondering what would be waiting for him at home: 'I was just sitting there praying.'

Nearby, Shannon Sledd waited out the storm in the house she shares with her disabled parents and her two sons. Floodwaters up to 5 feet deep rose up to her front door, but didn't get inside.

'My mom and dad are really nervous,' Sledd said. 'We might have to get out.'

In North Carolina, steady rains have already disrupted communities from the central part of the state to the coast.

Some roads were closed Wednesday in Guilford County, and emergency medical service Director Don Campbell said he feared that more rain expected through the weekend would topple trees and knock out power.

Along the coast, parts of North Topsail Beach eroded from rains and an unusually high tide over the weekend, so officials were watching the hurricane's approach.

'We haven't had time to recover from last weekend,' said Carin Faulkner, the assistant town manager.

In New England, a sudden downpour Wednesday led to flooding and slow commutes. Western Massachusetts got up to five inches in just hours, according to the National Weather Service.

College student Krystal Diaz said her commute by bus to downtown Providence from nearby Johnston had been especially long because of poor visibility and heavy traffic.