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Almost two weeks after a devastating earthquake hit China, the country is facing further problems as torrential rain and strong winds continue to lash many southern provinces.

Measuring 7.9 on the Richter scale, the quake struck the Sichuan province and caused numerous landslides which in turn created lakes known as ‘quake lakes’. With many lakes swollen to their banks, over 150,000 people have since been evacuated over fears that the continual heavy rain could cause the lakes to flood.

Since Sunday more than 15 people have been killed in the widespread floods which have been sweeping the southern region of Guizhou. Across 17 cities, almost half a million people have now been affected by the heavy rain. For many, the worst may not yet be over, as forecasters at the Chinese Meteorological Centre expect the heavy rain to continue for the next few days.

The first tropical storm of the Eastern Pacific season approached Central America and made landfall in Nicaragua this morning.

Alma hit land near the city of Leon with sustained winds of 55mph (90km/h) and gusts of 65mph (105km/h). There was widespread damage to property and many trees were blown over blocking roads and knocking down power lines. Over 150,000 people are without electricity and telephone services.

Tropical storm Alma intensified from a tropical depression while it was off the coast of Central America in the east Pacific. The storm took forecasters by surprise when it intensified quickly just before making landfall. Fortunately for Nicaragua, tropical storm Alma hit land before it could become a hurricane. Alma will now continue to weaken over land, but could still bring torrential rain and flash flooding to Honduras as it moves further into Central America. Authorities have been warning the Honduran public to evacuate from low-lying areas due to fears of flash flooding and mudslides.

Central America is particularly at risk from tropical storms which can strike from both the eastern Pacific side, or from the Atlantic side. In 1998, Hurricane Mitch, which deeply intensified over the warm Gulf of Mexico, devastated large parts of Central America killing over 10,000 people.

Tropical storm Arthur yesterday became the first named storm of the 2008 Atlantic Hurricane season, developing off the coast of Mexico. Forming a day before the start of the season, the weak tropical storm quickly made landfall over the Belize-Mexico border, packing winds of around 40mph (64kph).

The storm dumped rain as far south as Belize City, whilst hampering the surf conditions along the popular tourist island of Ambergis Caye, north east of Belize. The National Hurricane Centre said that within the next 24 hours Arthur could produce between 125-250mm (4.9-9.8 inches) of rainfall over parts of Belize and Guatemala.

As of Sunday morning the storm has weakened into a tropical depression and is currently moving west. Despite the small chance of Arthur strengthening back into a storm, forecasters say it is not likely to neither make hurricane status nor threaten the US Gulf coast.

A flood alert has been issued for parts of Queensland as heavy rain continues to intensify across the region. The Australian Bureau of Meteorology warned that overnight rainfall totals of more than 100mm (3.94 inches) are expected through Monday night, with flash flooding likely. Most of the beaches on the Sunshine and Gulf coast have been closed for the next 24 hours, with the rain creating dangerous surf conditions.

Queensland is one of the wetter states in north east Australia, but this amount of rainfall is unusual, especially for this time of year. Although the development of a front along the eastern coast is quite common, the amount of rainfall is not. The average monthly rainfall for June in Queensland is 66mm (2.6 inches), meaning some places will receive nearly double their monthly rainfall over the next 24 hours.

The unsettled weather is set to continue, at least until the middle of the week, with forecasters expecting the rainfall to intensify over the coming days.

The southwestern summer monsoon arrived a day early this year, drenching parts of India and the nearby regions with heavy rain. The ‘southwest monsoon’ refers to the winds during the rainy season, which normally runs from June until September. Due to the Indian subcontinent heating up over the summer seasons, an area of low pressure is created over central India, bringing heavy rain.

At least 15 people have been killed by this year’s monsoon in Sri Lanka, while more than 150,000 have been made homeless. Torrential rain has been lashing the Indian Ocean nation’s western districts of Colombo, Gampaha and Mathara; Colombo being one of the worst hit areas.

Forecasters at the Indian Meteorological Centre expect the rainfall to become more organised over the next few weeks as the monsoon pattern begins to settle.

Tornadic thunderstorms developed across parts of the Mid-West last night causing flooding, hail damage and power cuts.

A cluster of violent storms pounded parts of Nebraska, unleashing torrential rain with golf ball size hailstones and producing a tornado which touched down near the town of Ulysses. Power lines were torn down, farm houses shattered and trees were left twisted and strewed. Another tornado was spotted in Chase County in the southwest of the state, near the town of Wauneta with further damaged reported. Much of the state remains under a tornado and flood watch, with flash flood warnings being issued for central and eastern Nebraska.

Tornadoes were also reported in Indiana where violent storms broke out yesterday injuring dozens and killing one.

Severe thunderstorms are not uncommon across Tornado Alley at this time of year. Tornado Alley lies in a belt from Texas through much of the Mid-west and up into Minnesota and the Dakota’s. In spring, cold, dry air from the Rockies is dragged down onto the flat plains by low pressure and often collides with warm and humid air from the Gulf of Mexico. Severe thunderstorms form in lines called Squall Lines along the boundary of these air masses. They often produce tornadoes, large hail and frequent lightning. The majority of tornadoes occur in the months of March, April and May, but many can often form in June.

Further thunderstorms are likely to develop across the north Mid-West over the next few days.

The BBC’s Simon Hancock has been chasing storms through Tornado Alley. He joined a professional team which hunts out tornadoes using hi-tech equipment.

After two years of below average rainfall, Governor Arnold Schwarzenegger declared California in a state of official drought. It is the first official drought since 1991 when a state of emergency was declared after five years of below average rainfall.

California is prone to drought due to the pattern of air circulating above the state. The area lies under the Hadley cell, which is a circulation pattern that dominates the tropical atmosphere. This circulation is directly related to the trade winds, rain belts and subtropical deserts. The location of California underneath the descending part of the air results in a high pressure area, which creates a set of dry, settled conditions.

The state depends on its winter snow accumulation in the Sierra Nevada for much of its supply of water. However March, April and May have been the driest winter months on record this year. Californians are being made aware of how serious the water crisis has become, and are now being forced to mandate water conservation or rationing.

Two days after thunderstorms lashed the US Midwest, another line of storms rolled through the region on Friday, in the latest round of fierce weather. These violent storms smashed houses, deluged neighbourhoods and left thousands without power. The sequences began on Thursday, causing flash floods across Missouri and Minnesota, and later hail storms. High winds delayed over 200 flights at Chicago’s O’Hare airport, gusting up of 72 mph (116kph) in some places.

Over 175 incidents of severe weather were reported on Friday, with weather warnings for the cities of Detroit and Indianapolis. Heavy rain continues across the northern Plains and upper Midwest, with the storms forecast to persist until the start of next week. The rain on Thursday gave Houghton in Michigan its wettest June day on record, with 72mm (2.84 inches) being recorded.

Whilst a number of counties across the Midwest remain on flood alert, the north east of the country is sweltering under blistering heat and high humidity.

Heavy rain and storms across a swathe of southern China including Hong Kong have lead to flooding with mudslides that have injured dozens and crippled transport.

In some places, nearly 305mm (12 inches) of rain has fallen over the past few days. Flash flooding triggered more than 40 landslides in the Hong Kong area alone. At Hong Kong International Airport, flooding severely disrupted traffic as muddy water flowed over the runways. More than 345 flights were cancelled during the peak of the heavy rain.

Heavy monsoonal rains have also been drenching other parts of South China. The Guangdong Province was hit by extreme rainfall with hailstorms which caused flooding and damage to hundreds of acres of crops. Severe thunderstorms affected Yichang City in Hubei where frequent lightning caused blackouts across parts of the city.

Although the recent rain across southern parts of China have been particularly severe, very heavy rain at this time of year is not unusual. During the summer, a southeast monsoon from the western Pacific Ocean and a southwest monsoon from the equatorial Indian Ocean blow onto the Chinese mainland producing the country’s heaviest rainfall of the year.

Many parts of southern China and Hong Kong remain on flood alert as more heavy rain is expected over the coming days. Authorities are warning residents of the risk of further mudslides.

As further storms roll across the US Midwest on Sunday, eastern states were reeling under a heat wave that saw temperatures peak at 38C (100F) in Raleigh, North Carolina. Extreme heat has affected almost a third of the US, with temperatures in Philadelphia, Richmond, Macon and Charlotte reaching record breaking highs. Residents of New York sweltered under temperatures of 32C (90F) on Sunday, compared with the seasonal average of 25C (77F).

In the Midwest, the contrast between the cool, dry air from the north and the warm humid air from the south has helped fuel another line of severe thunderstorms. More than 3 inches (76mm) of rain fell in Indiana yesterday, resulting in yet more widespread flooding.

Although the storms look set to continue over the next two days, there are signs that the heat wave is beginning to ease, as the ridge of high pressure which has been sustaining it begins to move further east. With the winds switching to a southerly direction in the coming days, forecasters are keeping a close eye on those areas which are prone to wild fires.