California’s Bay Areas, such as Oakland, experienced record temperatures on Thursday with a high of 98F (36.7C) breaking the previous record for that day of 87F (30.6C). Both San Francisco and San Jose also broke records. Woodland hills (southern California) hit a new record on Friday with a high of 101F (38.3C).

In Oregon triple digit temperatures sent folks scrambling to the beaches for relief on Thursday. Brookings Harbour residents turned up the air conditioning, hit the beach or fled to the Chetco River to escape 101F (38.3C). It was the highest temperature recorded in Brookings in May since records began in 1931. The previous record high for May was 99F (37.2C) in 1943.

An unseasonably strong area of high pressure over the eastern Pacific has brought these high temperatures and low humidity air to the area. The weather conditions were expected to continue through the weekend, and on Saturday the National Weather Service issued a heat advisory.

The Weather Service expects temperatures to slide back down to the nineties early in the new week as the air moves in from the sea rather than the land. Temperatures however will still be above average.

While much of Australia has been suffering its worst drought in over a century, the recent rain brought a relief to farmers. For many it was the heaviest rain experienced in months. Victoria’s wettest place, Weeaproinah (in the Otways), bore no surprises as it totted up the most rainfall over the weekend, 57mm (2.24 inches).

Skiers and snowboarders also had a good reason to celebrate with snow falling at all three major ski resorts and with less than three weeks to go to the start of the winter season. As much as 30cm (11.8 inches) fell at Falls Creek.

On Saturday, Melbourne failed to reach double figures with a high of 9.5C (49F), giving it its coldest May day since 1977. Today though, temperatures have returned to nearer average for May which is 17C (63F).

Showers are forecast still over the next couple of days as further cold fronts cross the state. However, high pressure over South Australia is expected to move in late Wednesday bringing drier conditions to end the week.

According to the Florida Division of Forestry, over 90 fires were burning out of control over the weekend. Some of the worst fires affected the Everglades National Park, with several burning near Lake Okeechobee. All in all, around 40,000 acres (16,188 hectares) of drought stricken land have been scorched, with many blazes still burning out of control.

This is the second year of drought conditions in Florida. According to the National Drought Monitor, approximately 20% of the state has been experiencing severe to extreme drought conditions since the start of this year. The worst affected areas are across the southwest and the Kissimmee River watershed.

It is thought that moderate La Niña conditions in the equatorial Pacific are the cause of the droughts. These droughts are intensified during the winter and spring months. Over the past week, high pressure has been in control of Florida’s weather causing it to stay sunny and dry with very little moisture in the atmosphere.

A little relief from the hot dry spell may be on the way for central parts today and over the next few days, as forecasters are expecting scattered thundery showers. The severely drought-stricken south, however, is unlikely to see any substantial rainfall and will remain hot and dry for the rest of this week; thus maintaining a high fire hazard.

High pressure currently centred over Tasmania will slip south and slightly eastwards to the west of New Zealand over the next few days introducing Antarctic air up across New Zealand. An active cold front, associated with a low pressure system to the east of the country, is forecast to spread across the South Island, bringing heavy rain to many parts before Thursday. Gale force, cold southerly winds will follow in behind the front, turning the rain into snow.

The Met Service issued warnings for heavy rain across Fiordland and southern Westland. Some areas may see in excess of 80mm (3 inches) tonight. When the cold air arrives tomorrow, heavy snow and blizzard conditions are likely over the hills of northern Southland, South Canterbury and inland Otago over the next few days. The Met Service has warned that up to 20cm (8 inches) could fall, making driving conditions treacherous and cutting off roads and passes over higher ground.

The opening dates of the New Zealand skiing season vary between resorts, but most of these are due to open during the last week of June. This heavy snow event will see a good covering of snow on the slopes a month before the opening date.

High pressure and southerly winds earlier in the week caused temperatures to soar not just across Arizona but across most of the western US. Highs last Sunday rose above 38C (100F) in Phoenix for the first time this year, peaking at 41C (105F). The heat then intensified on Monday, soaring to 43C (110F) and prompting the issue of excessive-heat warnings. This was the first time since records began in Phoenix that the 38 and 43C (100 and 110F) marks were reached on consecutive days.

Yesterday though saw an area of low pressure collide with moist air off the Gulf of Mexico, triggering severe thunderstorms across the High Plains. Snow advisories were issued for the mountains of Wyoming, Colorado, Utah and Montana.

The storm also brought cooler temperatures and strong winds across Arizona, with a change to westerly winds off the Pacific. On Wednesday highs were nearer 34C (93F) in Phoenix. However the forecast is for temperatures to drop further over the next couple of days, with a risk of storms. Highs are expected to fall into the low to mid 20Cs (70s in Fahrenheit).

With less than two weeks to the start of the season, the NHC are predicting that 2008 will be more active than normal with 12-16 named storms of which six to nine could progress to hurricane strength. Of these hurricanes they say that two to five are likely to become major hurricanes of Category 3 or above according to the Saffir-Simpson Hurricane Scale. This corresponds to winds of 111mph (179km/h) or more.

After more recent predictions have not come to fruition, raising criticism, the NHC has for the first time included a probability in their forecast. While the last two years have seen average or below-average activity, they have warned that there is no reason to believe this will continue and have urged the importance of being prepared.

Over the last two years the US has come off relatively unscathed with no hurricanes making landfall at all in 2006. Last year the season yielded six hurricanes of which three became powerful lashing the Caribbean and Central America. Only one made landfall in the US though, Humberto, which was relatively weak.

Although the last two years have been quiet in the US, the public need only remember the devastation caused by Hurricane Katrina in 2005, to understand the importance of these predictions.

At least five people have been killed with around 15,000 displaced by the floods. Rivers burst their banks around the port area of Valparaiso, flooding hundreds of homes and cutting off roads. One of the worst affected areas was across the Maule region, just south of the capital, Santiago. Here, much of the fertile agricultural land was washed away when the Lontue River bursts its banks.

The recent heavy rains were due to a series of low pressure systems which developed over the Pacific Ocean and moved inland. At the peak of the rains, more than 90mm (4 inches) fell in the Maule region on Thursday. Temperatures are starting to fall across much of the country as high pressure builds from the west, drawing up colder southerly winds.

Despite large parts of Chile seeing a brief spell of drier and brighter weather this weekend, further rain is expected at the start of next week. With cooler air around, much of the rain will turn into snow as it reaches the Andes mountain range, with the risk of some heavy snowfalls expected towards the east of Santiago.

Chile is one of the driest countries in the world and regularly suffers prolonged droughts through the summer months. However, during autumn, low pressure often takes charge of the weather, bringing a succession of fronts across the country which can lead to flooding as the ground is so dry from the summer months.

Parts of Kansas were hit by at least 17 tornadoes on Friday alone, according to the National Weather Service. The storms destroyed several buildings and left at least six people injured.
Two people were found dead in a car, reportedly killed by a passing whirlwind.

Tornadoes and hail storms also ripped through Oklahoma on Saturday damaging several buildings, including one that decimated barns at a pig farm. Trees were uprooted and a mobile home was tossed onto a major highway.

Portions of Kansas were also under flood warnings with as much as 8 inches of rain falling in a 48 hour period.

Saturday’s slow-moving storm followed two days of violent weather in the Midwest. In Kansas, the clean-up is under way but further tornadoes are still forecast.

According to the Weather Service, twisters have caused the deaths of around 100 people in the U.S. so far this year, the worst toll in a decade, and the danger has not passed yet. Tornado season typically peaks in the spring and early summer, and then again in late autumn.

Heavy and persistent rain on Monday morning across southern counties of England gave rise to flash flooding in some places. Parts of the south have received more than 25mm (1 inch) of rain this morning and forecasters are warning of more heavy rain to come. Flooding in Southampton caused chaos as dozens of roads in the city had to be closed.

Low pressure has been sitting to the south of the UK across the Bay of Biscay for the past few days. This has allowed a succession of active fronts from the near continent to spread north and westwards across the southern half of England and Wales. In contrast, the north of the UK has been under the influence of high pressure which has given much of Scotland, northern England and Northern Ireland fine, dry and settled weather with long spells of sunshine and brisk easterly winds.

Scotland and Northern Ireland have been particularly dry this month with many areas only receiving 10 to 25% of the expected monthly May rainfall. Meanwhile across the south, parts of Devon and Cornwall had seen more than three quarters of their average monthly rainfall, even before the downpours of the last couple of days.

With more heavy and thundery rain expected to fall, parts of the south already affected by heavy rainfall could well see more than twice the May average before the end of the month.

The US Midwest is prone to tornadoes and thunderstorms as a result of the contrasting air masses found in that area. Cold air from the Rockies meets with warm and moist air from the Gulf, creating instability and as a result an increase in activity.

The tornado came after several days of severe weather across the US. Over the weekend heavy rains battered Oklahoma, with further thunderstorms expected across the Midwest in the coming days. A state of emergency still remains in Washington County as local aid agencies help residents recover from the tornado.