Keeping Perspective on the Weather

There has been a lot of news about "record high temperatures" in the US. The reason for this is that the jet stream is at an unusually high latitude this summer. With all the news focused on "record highs" people lose perspective. Here is the picture of precipitation (left) and temperature (right) over the last 30 and 90 days in the US:

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All that blue in the western US is below normal temperatures. I'm sure most people have already forgotten that it was so cold.

We have just left an El Niño event in the Pacific and are entering a La Niña event. Here's what Wikipedia has to say about the expected effects in North America:

La Niña causes mostly the opposite effects of El Niño. La Niña causes above average precipitation across the North Midwest, the Northern Rockies, Northern California, and in the Pacific Northwest's southern and eastern regions. Meanwhile there is below average precipitation in the southwestern and southeastern states.

La Niñas occurred in 1904, 1908, 1910, 1916, 1924, 1928, 1938, 1950, 1955, 1964, 1970, 1973, 1975, 1988, 1995.

Atlantic tropical cyclone activity is generally enhanced during La Niña.

In Canada, La Niña will generally cause a cooler, snowier winter, such as the near record-breaking amounts of snow recorded in the La Niña winter of 2007/2008 in Eastern Canada.

Here is what Wikipedia says about the "jet stream" during El Niño and La Niña and its effect on the weather:

The changing of the normal location of upper-level jet streams can be anticipated during phases of the El Niño-Southern Oscillation (ENSO), which leads to consequences precipitation-wise and temperature-wise across North America, affects tropical cyclone development across the eastern Pacific and Atlantic basins. Combined with the Pacific Decadal Oscillation, ENSO can also impact cold season rainfall in Europe. Changes in ENSO also change the location of the jet stream over South America, which partially affects precipitation distribution over the continent.

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Across North America during La Niña, increased precipitation is diverted into the Pacific Northwest due to a more northerly storm track and jet stream. The storm track shifts far enough northward to bring wetter than normal conditions (in the form of increased snowfall) to the Midwestern states, as well as hot and dry summers. Snowfall is above normal across the Pacific Northwest and western Great Lakes. Across the North Atlantic, the jet stream is stronger than normal, which directs stronger systems with increased precipitation towards Europe.

You can read the weekly Enso Cycle report from NOAA. Here's the summary from the latest report:

•La Niña conditions are developing across the equatorial Pacific.
•Negative sea surface temperature anomalies continue to strengthen across much of the Pacific Ocean.
•The onset of La Niña conditions is likely during July-August 2010.

I would say that you can safely ignore the doom-and-gloom crowd who are telling you that "global warming" is upon us and we have not hope, i.e. that runaway warming will turn us into crisp blackened toast. In the real world, we are caught in a changing weather cycle. The heat wave is explainable as an effect of the ENSO cycle.

As for us dying as the world melts... you need only look at Antarctica to see that there is a record amount of sea ice this year. Somebody forgot to tell Antarctica that this white stuff is supposed to be gone like the Dodo bird never to be seen again...

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As you can see, there is an anomalous amount of ice: more than average by almost 1.2 million sq. km.! This is a lot of ice. You can investigate sea ice around the world at the University of Illinois Polar Research Group's Cryosphere site.