A strong fall storm moving into Arizona on Thursday is expected to drop up to three inches of snow in the higher elevations. The National Weather Service said the greatest likelihood of severe storms will be from Thursday evening through Friday morning. Daytime temperatures Friday will be about 15-20 degrees cooler than earlier this week.

Up to three-quarters of an inch of rain is expected in some areas, with the possibility of tornadoes.

Forecasters said snow levels could drop to as low as 7,500 feet on Friday. The Kaibab Plateau, San Francisco Peaks and the White Mountains could see between one inch and three inches of snow.

100-year-old cold records broken, but nary a word. "An incredible departure from normal happened with yesterday's lows out there," says reader Ralph Fato. "Some spots were 25-30 below normal, breaking record-cold lows. Some records over 100 years old!"

An early season snow event produced significant snow amounts for northeast North Dakota into northwest Minnesota for early October. The heaviest snow fell in Roseau county where around a foot of heavy wet snow has been reported as of 3 pm Thursday October 4. This heavy wet snow has also produced numerous power outages across this area.

These snow amounts appear to be record amounts for this early in the season for many areas. The previous record snowfall for October 4 or earlier at the NWS in Grand Forks was 2 inches on October 2, 1950. The NWS at Grand Forks reported 3.5 inches of snow with this storm on October 4, 2012. While records from around the area indicate that the October 2, 1950 storm produced about 2-5 inches around the region with localized higher amounts, with Leeds, ND receiving 7.0 inches on October 2, 1950, and Hallock 4.5 inches.

Climate change researchers have detected the first signs of a slowdown in the Gulf Stream - the mighty ocean current that keeps Britain and Europe from freezing.

They have found that one of the "engines" driving the Gulf Stream - the sinking of supercooled water in the Greenland Sea - has weakened to less than a quarter of its former strength.

The weakening, apparently caused by global warming, could herald big changes in the current over the next few years or decades.

Paradoxically, it could lead to Britain and northwestern and Europe undergoing a sharp drop in temperatures.

Such a change has long been predicted by scientists but the new research is among the first to show clear experimental evidence of the phenomenon.

Peter Wadhams, professor of ocean physics at Cambridge University, hitched rides under the Arctic ice cap in Royal Navy submarines and used ships to take measurements across the Greenland Sea.

Light rain turned over to light snow for a time late Friday night at the Duluth airport, resulting in the city's first official measurable snowfall of the season, and its earliest measurable snowfall in 17 years.

The National Weather Service recorded a tenth of an inch of snow for the day. Weather spotters in Alborn and near Canyon reported three-tenths of an inch of snow overnight. Any snow that fell didn't last long, as ground temperatures remained warm and air temperatures climbed back above 40 in the early morning hours.

Duluth's tenth of an inch was short of the record for the date - two-tenths of an inch, which fell in 1974. One-tenth of inch of snow also fell on Sept. 21, 1995, the Weather Service reported.

The Weather Service had previously reported a trace of snow on Wednesday, which tied a record for the date. A trace is not considered measurable snow.

The earliest measurable snow in Duluth was in 1991, when 2.4 inches fell on Sept. 18. The average date for the first measurable snow in Duluth is Oct. 24.

Canada - On the last day of summer, a few rogue snow flurries were actually spotted in Winnipeg Friday.

But Environment Canada's senior climatologist is sticking to his story.

Dave Phillips says Manitoba is still headed for a warmer-than-normal fall.

Phillips said after one of the hottest summers ever across Canada, Manitoba's lakes, rivers and the land are still very warm.

"There's a lot of residual heat that may certainly keep us warm as we move into October," he said.

That's certainly true in the short term, he added.

"Over the next few days nothing but that great Manitoba sunshine wall-to-wall."

Phillips is forecasting October to be warmer than normal, with normal to less-than-normal precipitation.

Britons can wave goodbye to the autumn as swathes of the country are set to be hit with freezing cold temperatures, frost and gale-force winds in an abrupt end to the balmy season.

Heavy rain and winds as strong as 50mph are expected to put a dampener on any weekend plans with some places seeing temperatures drop below freezing.

As the weather appears to skip a season, some parts of the country will feel frost tomorrow morning and gritters are already in place in preparation for winter.

"Day 258 of 2012 is the highest for this date since satellite scanning of Antarctic ice areas commenced 33 years ago" the New Zealand Climate Science Coalition announced today. "It is also the fifth highest daily value on record." Coalition chairman, Hon Barry Brill, says the most remarkable aspect is the extent to which the 2012 area exceeds normal Antarctica averages. "The sea ice cover yesterday was 311,000 square kilometers above the 1979-2012 average. The surplus ice is more than twice the area of New Zealand." The Antarctic dimensions come partly at the expense of Arctic sea ice," said Mr. Brill. "Over the 33-year period aggregate global sea ice volumes have remained steady, but there are fluctuations between the two polar areas from year to year.

The fluctuations are the result of ocean currents and wind patterns, rather than temperatures. Antarctic ice is much more important than that of the Arctic. The area of its sea ice is a million square kilometers larger than the highest value ever recorded in the Arctic. Then, of course, the Antarctic is an entire continent, with more than 90% of the earth's glacial ice," said Mr. Brill. "It is appropriate that this record should occur in a week that The Listener carries a cover story featuring the winter low point of Arctic ice, along with multiple pictures of calving glaciers and forlorn polar bears," said Mr. Brill. "The magazine has little to say about the Antarctic apart from complaining that it is "poorly understood."

The author also avoids mentioning the glaring facts that no significant global warming has been recorded in the past 16 years, and that sea level rise is apparently decelerating. "It is unfortunate that under-informed writers, albeit unwittingly, mislead their readers who should be helped to understand the difference between sea ice extent and ice cap ice, both thickness and extent as regards the latter. The ice cap in the Arctic is small compared to the Antarctic. The cap of the Antarctic is increasing in thickness in most places, except around the Antarctic Peninsula. Sea ice extent is largely a consequence of sea surface temperature, ocean currents and wind," said Mr. Brill, who advised those interested in graphic confirmation of Antarctic sea ice readings to refer to this link as well as this link.

Sydney -- A huge meteor striking Earth 2.5 million years could have generated a massive tsunami and plunged the world into the Ice Ages, Australian researchers suggest.

Scientists at the University of New South Wales say that because the meteor -- more than a mile across - crashed into deep water in the southern Pacific Ocean, most researchers have discounted its potential for catastrophic impacts on coastlines around the Pacific rim or its capacity to destabilize the entire planet's climate system.

"This is the only known deep-ocean impact event on the planet and it's largely been forgotten because there's no obvious giant crater to investigate, as there would have been if it had hit a land mass," lead study author James Goff said in a university release Wednesday.

Goff is co-director of UNSW's Australia-Pacific Tsunami Research Centre and Natural Hazards Research Laboratory.

Scientists say they have new evidence to support the idea that a space rock crashed into Earth about 12,900 years ago, wiping out some of North America's biggest beasts and ushering in a period of extreme cooling.

If such an impact took place, it did not leave behind any obvious clues like a crater. But microscopic melted rock formations called spherules and nano-sized diamonds in ancient soil layers could be telltale signs of a big collision. The mix of particles could only have formed under extreme temperatures, created by a comet or asteroid impact.

Researchers first reported in 2007 that these particles were found at several archaeological sites in layers of sediment 12,900 years old. Now an independent study published in the (Sept.17) in the Proceedings of the National Academy of Sciences (PNAS) says those findings hold up.