Texas is forecast to be HOTTER than 99% of the world as temperatures surpass 107F

Parts of Texas are poised to be hotter than 99 percent of the world Wednesday afternoon - as a dangerous heat wave continues to batter the US South.

Residents in cities such as Houston can expect temperatures north of 107 degrees -  with factors such as humidity creating a climate that will feel even hotter.

As a result, the North Texas locale, as well as others such as Fort Worth, Dallas, and San Antonio are all under an excessive heat advisory - and are at risk of blackouts.

Concerns of power loss are not unfounded - as hundreds of thousands in the Southeast already lost power last week due to increased demand, following an even worse round of outages last summer.

'Only the Sahara Desert & Persian Gulf area will be as hot or hotter than the Lone Star State,' Ben Noll, a meteorologist with New Zealand's National Institute of Water & Atmospheric Research, said last week of the weather expected later Wednesday. 

Brought on by a historic 'heat dome' that has wreaked havoc on Texas in particular, the scorching temperatures have led to at least three deaths, and saw the Lone Star state's private power grid destroy its all-time demand record Tuesday.

Scroll down for video: 

Parts of Texas will be hotter than 99 percent of the world Wednesday afternoon - as a dangerous heat wave continues to batter the American South

A woman and her grandson buy a bag of ice during a period of hot weather in San Antonio Tuesday. At the time, the Texas city was the fifth hottest in the country. It is now set to again see temperatures near 110 degrees on Wednesday

Residents in cities such as Houston (seen here Tuesday) can expect temperatures around 107 degrees - with factors such as humidity creating a climate that will feel eight degrees hotter

Meteorologists are now warning that the worst has yet to come - with Wednesday set to be the hottest day yet, and the dome now expected to expand to other parts of the US during the coming week. 

The National Weather Service similarly warned: 'Drink plenty of water, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.' 

Texans have already been battling extreme heat for more than two weeks - with daily temperatures regularly topping 100 degrees.

Meteorologists' measuring stick for such matters, the heat index, provides an estimate of how hot it actually feels outside - and shows that the feels-like temperature for cities like Dallas could be as high as 115.

The city, along with others in the eastern part of the state such as Houston, will see the highest temperatures Wednesday afternoon, the service said - adding that residents can expect 'heat indices as high as 115 in the east.'

Toward the west, in locales such as San Antonio, Texans can expect highs 'from 105 to 110.'

The measurement is used to indicate when heat is dangerous for the human body, and does not take into account things like sunlight and cloud cover. 

When out in the sun, a person could perceive that temperature as being higher by another 15 degrees - a cause for concern as the weather could easily prove fatal Wednesday.

The slow moving heat mass has already languished over the state for several weeks, killing three Texans - a 14-year-old boy and his stepfather who died while hiking in Austin Friday - where temperatures were 119 degrees - and Dallas mailman Eugene Gates Jr, 66, who also collapsed and died while making deliveries on June 20. 

The slow moving heat mass has already languished over the state for several weeks, killing three Texans - a 14-year-old boy and his stepfather who died while hiking in Austin Friday - where temperatures were 119 degrees - and a Dallas mailman aged 66

People in Austin (seen here Tuesday) are also set to experience highs that surpass 107 degrees - after the city was awarded the dubious distinction the hottest in the country yesterday

The National Weather Service warned for Wednesday: 'Drink plenty of water, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors'

Firefighter EMT William Dorsey lifts a migrant woman suffering from heat exhaustion onto a stretcher in the border community of Eagle Pass, Texas. The slow moving heat mass has affected communities in Texas and Mexico for the past few weeks, killing at least three

When out in the sun, a person could perceive that temperature as being higher by another 15 degrees - a cause for concern as the weather could easily prove fatal Wednesday

'Only the Sahara Desert & Persian Gulf area will be as hot or hotter than the Lone Star State,' Ben Noll, a meteorologist said last week of the weather expected - poised to be the worst of the ongoing heat wave

Worsening matters, is the fact that temperatures won't cool down overnight, due to extreme humidity creating for an environment that does not allow overnight temperatures to cool - a new phenomenon that offers little reprieve to those dealing with the heat during the day

The National Weather Service cited this threat in this week's heat wave in a recent statement, as the threat of blackouts looms large

A woman shields herself from the sun in Austin, when temperatures neared 110 degrees. The city has reported an uptick in heat-related emergencies over the past two weeks amid the record-breaking heat wave, with hundreds of calls for service to deal with the sweltering heat

Texas has been battling extreme heat for more than two weeks with daily high temperatures near 110 degrees

A Texan is seen trying to cool off in between sets as he braves the triple-digit warmth, which officials now say is set to remain for at least a week

A pair of firefighters in Austin try to cool down after fighting a fire at an abandoned apartment complex over the weekend

Cities in the eastern part of the state will see the highest temperatures Wednesday afternoon, the service said - adding that residents can expect 'heat indices as high as 115 in the east.' Toward the west, in locales such as San Antonio, Texans can expect highs 'from 105 to 110'

Worsening matters, is the fact that temperatures won't cool down overnight, due to extreme humidity creating for an environment that does not allow overnight temperatures to cool enough.

A relatively new phenomenon, the steady temps offer little reprieve to Texans dealing with the oppressive heat during the day, some of whom may not  have access to air conditioning.

The National Weather Service cited this threat in this week's heat wave in a Monday statement.

It warned: 'There may be more danger than a typical heat event, due to the longevity of near-record or record high nighttime lows and elevated heat index readings.'

The hotter climate, scientists have warned, is a consequence of the continued climate crisis - which is, again, hopelessly hampering Texas's resident power grid.

As a result, Electric Reliability Council of Texas (ERCOT), the state's main grid operator, has issued a weather watch through Friday - in anticipation of high electricity demand.

The state power grid last year and the year before became a household name, following mass outages wrought by 2021's Winter Arctic Blast, and then again in 2022 with another abnormally hot summer.

The firm has since vowed to keep Lone Star State's lights on at all costs - a tall task come Wednesday. 

The temperatures have already led to at least three deaths - including that of a 14-year-old boy who died while hiking on Big Bend National Park in Austin, as well as his 31-year-old stepfather

United States Postal Service worker Eugene Gates Jr, 66, pictured with his wife Carla, also died last week in Lakewood, Dallas, when he collapsed and died while making deliveries

ERCOT, which operates the grid for more than 26 million customers representing about 90% of the state's power load, said it has enough resources to meet current demand.

ERCOT had forecast demand would set records on several prior days since mid-June but it did not do so until Tuesday, in part because consumers heeded the grid operator's June 20th call to conserve energy.

Extreme weather was a reminder of the 2021 February freeze that left millions of Texans without power, water and heat for days during a deadly storm as ERCOT scrambled to prevent a grid collapse after an unusually large amount of generation shut.

Although U.S. power demand is projected to ease in 2023 after hitting a record high in 2022, rising economic and population growth is expected to keep boosting electric use in Sun Belt states like Texas.

On Tuesday, the Texas grid was operating under an elevated 'weather watch' that does not ask residents to curtail power but raises the possibility. Even some energy experts who have been critical of Texas' grid management consider outages this summer unlikely, saying winter carries bigger risks.

But as scorching temperatures in some parts of Texas climb above 110 degrees (43 degrees Celsius), flirting with records or breaking them outright, air conditioners are cranked and officials are nudging homeowners to be mindful of their electricity usage.

'Please, please do what you can to conserve energy,' said Stuart Reilly, interim general manager of Austin Energy, which serves more than a half-million customers in Texas' capital.

Forecasters say relief in Texas may not arrive before the Fourth of July holiday. 

The culprit, as previously mentioned, is the stalled heat dome - forged by an unpleasant mix of stationary high pressure, warml air in the Gulf of Mexico and the sun overhead, according to John Nielsen-Gammon, the state's climatologist.

Meanwhile, further east, hail and flash flooding has seen a total of 9,000  flights within the US delayed or canceled, as storms through states in the Mid-Atlantic and parts of the Northeast. Most of the delays were from New Jersey's Newark International, seen here Tuesday

This uncertain weather has led to disruptions for air travelers that continued Wednesday, with more than 9,700 flights across the US delayed or canceled

Meanwhile, the scorching heat seen in the South of the country is helping to fuel storms further north in the Mid-Atlantic and Great Lakes regions, which brought tornadoes to multiple towns in Indiana. A tornado Tuesday cannot be ruled out, officials said, as the obscene heat continues to fuel the stubborn system responsible 

Meanwhile, the scorching heat seen in the South is helping to fuel a stubborn storm system further north affecting the Mid-Atlantic and Great Lakes regions. 

A network of tornadoes and thunderstorms blasted those areas - as well as some parts of the South over the weekend - leaving at least three people dead in Indiana and Arkansas and a trail of destruction in their wake. 

The National Weather Service said multiple tornadoes and severe storms were reported barreling through both states on Sunday evening, with shocking images and footage from local media showing how fallen trees had blocked roads and homes were damaged. 

A large hail storm was also reported in Indiana and adjacent states, officials said.

The same system is set to be strengthened by current temperatures across the Central and Southern Plains, which, in conjunction with an approaching cold front, will set the stage for damaging winds in excess of 70mph, and golf-ball sized hail and more possible tornadoes.

This uncertain weather has led to disruptions for air travelers that continued Wednesday, with more than 9,700 flights across the US delayed or canceled.

Most of the delays were from New Jersey's Newark International, as the system hit the East Coast on Monday.