THE HEAT IS ON 

Scientists from Stanford University reported this week that the Northern Hemisphere will see an "irreversible rise in summer temperatures within the next 20 to 60 years," but the U.S. may already be getting a sneak preview. A brutal heat wave is rolling east across the country, pushing temperatures up to 103 in Minneapolis Tuesday and threatening similar misery throughout the Eastern Seaboard. Forecasters say temperatures could reach 20 degrees above average in the Northeast today, and an array of East Coast heat records are expected to fall by Thursday, the New York Post reports.

Despite all the thunderstorms that have plagued the Central U.S. for the past three months, intense sunshine has still been beating down on the country's midsection, building up a steamy dome of high pressure. That dome is now sliding east toward the Atlantic Ocean, and it's sparking dangerous heat along the way — temperatures in Houston soared to 105 on Sunday, for example, giving the Texas city its hottest-ever day in June. The heat then spread north and east on Monday, with highs of at least 90 degrees recorded in 28 states, and new high-temperature records set in 20 states. More than 600 such records have been set in U.S. cities since Saturday, and authorities are now issuing heat advisories all around the East Coast, including the D.C. and Baltimore metro areas, where heat indices today may reach 105 degrees today. The city of Baltimore has issued a code red heat alert for today and Thursday, while Philadelphia has an excessive heat watch in effect through Thursday evening. Temperatures will likely surpass 90 degrees from Burlington, Vt., south to Boston and New York City, AccuWeather warns, until they finally start to taper on Friday.

But the break from all this June heat will come at a price, AccuWeather adds — severe thunderstorms are forecast to flare up from the Great Lakes across most of New England tonight and Thursday, capable of producing damaging winds, large hail and possibly even an isolated tornado. In the meantime, though (and for areas that won't be reached by the rain), experts say it's important to be careful in this week's unusual heat wave. The National Weather Service has warned that the combination of high temperatures and high humidity could put people in danger of heat stroke and heat exhaustion, and it advises residents in affected areas to wear light, loose-fitting clothes and to drink as much water as possible.

(Sources: New York Post, Washington Post, Chicago Tribune, AccuWeather, Stanford University)

SMOKE SIGNALS 

A giant wildfire continues to race through the mountains of northern Arizona today, after growing by 66 percent Tuesday to burn a total of 608 square miles. That makes it twice the size of Chicago, the AP reports, and elevates it to the second-largest wildfire ever recorded in Arizona. Named the Wallow Fire, it has been at "zero percent containment" since it first broke out May 29, and is being driven by powerful winds of more than 60 mph, making it an especially fast-moving and erratic fire to fight. Smoke from the fire reportedly can be seen from as far away as Illinois.

"Everybody that's here is suffering from anxiety from this," Apache County Chief Sheriff's Deputy Brannon Eagar told residents at a public meeting in Eagar, Ariz., Tuesday night. "We never thought we'd see this roll over the hill, but it's here and we're going to deal with it the best that we can. Some people are frustrated, and I can understand that, and I'm sorry." About half of Eagar's 4,000 residents were forced to evacuate Tuesday as the Wallow Fire crept over ridges surrounding the area, the AP reports, joining several thousand other residents who have already fled the fire in recent days. Even U.S. Sen. John Kyl, R-Ariz., and his wife had to leave their cabin in Greer due to the advancing flames, CNN reports. Weather forecasts project 20 mph winds with gusts up to 35 mph today, dangerous conditions that could help the fire expand or shoot out "spot fires" beyond the current fire line. "Further evacuations will come if this does not hold tonight," incident commander Joe Reinarz told reporters on Tuesday, suggesting more people may have to flee their homes today.

No serious injuries have been reported so far in relation to the Wallow Fire, and while it has put 343 structures at risk, only 10 have been destroyed, CNN reports. That's partly due to the area's low population density — much of the burned area is in the Apache National Forest, which is now closed — but the fire's fast pace has authorities worried about their ability to keep up as it moves into more communities. It passed the 2005 Cave Creek wildfire Tuesday to become the second-largest in state history, and is now behind only the Rodeo/Chediski fire of 2002, which burned 732 square miles. 

(Sources: CNN, NPR, Associated Press)

FLOOD OR FAMINE 

The U.S. isn't the only country to be plagued by both droughts and floods this spring — the Yangtze River region of China has been crippled for months by its worst drought in 50 years, but as the New York Times reports, now it's suddenly suffering from the exact opposite problem. An outburst of heavy rains is finally offering relief from six months of drought along the Yangtze, but the downpours are turning out to be too much for many areas, spurring floods in southern and eastern China that have killed 52 people and forced more than 100,000 to evacuate.

Nearly 8,000 houses have been destroyed by the floodwaters, Reuters reports, and swaths of farmland have also been swamped — causing an estimated $26 million worth of economic losses per day, according to China Daily, after six months of drought already caused widespread crop failures. Most of the deaths so far have been concentrated in the impoverished southern province of Guizhou, where tens of thousands of residents have already fled their homes in recent days to escape the encroaching floodwaters, according to the state-run Xinhua news agency. The other deaths have mostly occurred in the eastern province of Jiangsu, Xinhua reports, although some parts of that same province also remain parched. Another 32 people remain missing, Reuters reports, and Xinhua suggests the death toll could still rise. More rain is forecast for Guizhou in the coming days.

Even with the trauma caused by the sudden floods, almost any kind of rain is still a welcome sight for many people throughout the drought-stricken region. The six-month dry spell has triggered water shortages for some 3.5 million people, the Times reports, but the rains have now dropped that number to 2.15 million. The amount of farmland affected by the drought similarly fell by 3.68 million acres, down to 5.68 million.

(Sources: New York Times, Reuters)

PAVE NEW WORLD 

Not only are big cities hotbeds of air pollution, but their paved surfaces can also make it harder for wind to disperse all that toxic air, according to a new study led by the National Center for Atmospheric Research. The researchers focused on the Houston metro area, discovering that paved surfaces like concrete and asphalt weaken the summertime breezes that would otherwise help sweep polluted air out to sea. While their findings may not apply to every big urban hub, they could have major air-quality implications for many fast-growing coastal cities in the U.S. and around the world, the researchers say.

"The developed area of Houston has a major impact on local air pollution," says NCAR scientist Fei Chen, lead author of the new study. "If the city continues to expand, it's going to make the winds even weaker in the summertime, and that will make air pollution much worse." Because paved surfaces soak up heat and keep the ground relatively warm overnight, they reduce the contrast between land and sea temperatures, the researchers say. That temperature difference is a key part of wind formation, and without it, the polluted air of Houston, Los Angeles, New York and many other coastal cities is left to languish on the streets where it was born. Chen cautions that more research is needed to fully understand the impact of pavement on wind patterns, but he points out the findings could at least help forecasters predict major pollution events, and may help elected officials devise new development plans to help cities clean up their own air.

Houston in particular has some of the highest ground-level ozone levels in the country, thanks largely to its legendary traffic jams combined with its dense array of oil refineries and other heavy-industry facilities. Battling local air pollution has been a long battle for city leaders, and Chen suggests that simply adding more parks, lakes and other greenspace could go a long way toward reducing the problem. "If you made the city greener and created lakes and ponds, then you probably would have less air pollution even if emissions stayed the same," Chen explains. "The nighttime temperatures over the city would be lower and winds would become stronger, blowing the pollution out to the Gulf of Mexico."

(Source: ScienceDaily)

THIS DAY IN HISTORY

Teddy Roosevelt creates the National Conservation Commission, [skipwords]organic farming[/skipwords] pioneer J.I. Rodale dies, and more.

Russell McLendon

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Photo (sun over Astoria Park in New York City): Global Jet/Flickr

Photo (smoke from Wallow Fire): Arizona Geological Survey

Photo (floods in Dexing, China, on June 7): ZUMA Press

Photo (asphalt road in Kyoto, Japan): matsuyuki/Flickr

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