Saturday 14 April 2012

Report on extreme weather in North America and Europe


Record Tornadoes & Weather in US, Severe Drought in Mexico and Europe

13 April, 2012

The following article is an excerpt of the Browning Newsletter, a key source of information in describing the relationship between macro weather-related trends and their potential impact upon energy, commodities, and the wider global economy. To subscribe to her montly newsletter, CLICK HERE.

Weather Notes from Around the World

This spring has already been a record-breaker. By March 25 the National Climatic Data Center March had already broken more than 6000 heat records!

On March 23, 2012, the US broke all tornado records with 319 reported tornadoes. The high temperatures, combined with the fact that winter left most of the nation’s ground unfrozen, has created ideal conditions for the type of low-lying thunder storms that are ideal for twister development.

Normally the entire month of March has 80 tornadoes. This year we had 160 tornadoes in a single outbreak. The only comparable year was 2008, also when a La Niña was ended. It should be noted, La Niñas tend to shift storm development eastward so that storms are more likely to appear in unexpected (and sometimes unprepared) places, like the recent swirl of 8 tornadoes hitting Michigan.

There was even a rare tornado in Hawaii! The same storm dropped the largest hailstone in Hawaiian history – 4.25 inches (10.8 cm) long.

Plants bloomed early throughout the Central and Eastern US, creating a record-breaking pollen season. The pollen count is soaring. Atlanta, for example, is setting a record, with “9,369 particles per cubic meter of air” when 1,500 particles are officially considered “extremely high.” Other hot spots for are Oklahoma and Tennessee. Unfortunately, (Achoo!) this has created a record allergy season. Normally allergists start getting their spring allergy patients in March. This February saw visits up as much as 30% and by March, doctors have been deluged.

Russia’s Sheveluch volcano has become more active. Ash plumes rose up to 4.3 miles (7.0 km) high each day on March 25-26 and 28. These eruptions were far too small to enter the stratosphere, but they were large enough to enter a cold front that is crossing the Pacific. This not only means cooler temperatures hitting the Pacific Northwest, but also heavier precipitation and the ash and chemicals fall out as acid rain and snow.

Mexico is facing the worst drought in its nation’s history. The water shortage wiped out millions of acres of farmland this winter, caused 15 billion pesos ($1.18 billion) in lost harvests, killed 60,000 head of cattle and weakened 2 million more livestock. Poor weather destroyed some 7.5 million acres (3 million hectares) of cultivable land in 2011 - an area about the size of Belgium or Massachusetts. An estimated 8 million people are affected and the government is having to provide food food rations to more than two million people.

The two years of La Niña has caused the drought and, with the negative Pacific Decadal Oscillation, the nation faces two more decades of drought risk. Expect these difficulties to not only affect Mexico, but also US immigration.

While Europe and the US are enduring drought, Australia is once again being deluged with spectacular floods. Australian State Emergency Service (SES) Commissioner Murray Kear reported that this year’s flood crisis was the most significant in a generation. It has affected an area the size of Spain (bigger than California). The eastern states of New South Wales, Queensland and Victoria have been hard hit. Thousands have been evacuated and several coal mines have been hit. (So far reports indicate that transportation and mining infrastructure damage has been far less than last year’s flooding.) The severe floods are as a result of the moderate La Niña which has been enhanced by the strongly negative Pacific Decadal Oscillation. (It should be noted that many scientists claim that the PDO is a Northern Hemisphere phenomenon, but it historically affects the behavior of El Niños and La Niñas.)

Droughts in North America and Europe

Summary: Conditions should improve for agriculture in North America. Historically years following La Niñas are good years for agriculture. However the rapidly flowing Atlantic and remnants of Iceland’s volcano eruption, which have caused freezes and drought in Europe, may continue to cause problems.

It’s springtime in the Northern Hemisphere. It’s planting season. After a peculiar winter and a hot, early spring, what can we expect?

This year, the planting issue is an even bigger concern than normal. The price of food soared in 2010 and remained high in 2011. It settled slightly in midyear but has started going up again. Much of this increase has been due to the impact of weather on food production. The cool La Niña, enhanced by the cold Pacific Decadal Oscillation interfered with the global precipitation patterns, particularly in the tropics and southern hemisphere. The growing season in the Southern Hemisphere saw drought baking Argentina and Brazil and tropical storms and floods lashing Australia.

Now the Northern Hemisphere is facing a planting season with major droughts in North America, drought in Europe and both flooding and drought in China.

Is it any wonder that the price of food is going up?



North America

La Niñas typically create dry conditions for the southern tier of states, particularly Southern California, Texas and the far southeast, around Georgia. We have seen these happen during both of the recent La Niñas with the drought in Texas lingered for two full years. Meanwhile, the positive NAO, by blocking winter storms from entering the Midwest, created drought around the Great Lakes. It has also enhanced the drought and raised temperatures (increasing evaporation) in the Southeast and along the East Coast.

By the second week of March, 48.8% of the US and 58.2% of the contiguous US was in dry or drought conditions. Much of this was concentrated in the Great Plains, “The Bread Basket” of the U.S. and Canada.



Historically, when La Niñas fade, so do the droughts. As the La Niña dwindled to a weak shadow of its former self, the rains returned. Powerful storms swept the West in the third week of March and record-breaking moisture swept Texas and parts of the parched Upper Midwest a week later.

What can history teach us about the weather following a winter La Niña?

If the La Niña retreats or is weak in early spring, the West can experience a “Miracle March.” Typically, the West, particularly the Southwest is dry in La Niña winters. This is important, because in most Western states, snowpack provides 60–80% of all water. In many areas, the winter is the wet season. This year, the Western snowpack was very low (73-81% below normal) through most of winter. It was only with the weakening of the La Niña, in February and March, that we saw more snow return to the Pacific Northwest and Northern California. Most of Washington, Idaho, Montana, Wyoming and Northern Oregon now have normal snowpack.



Fortunately, last year had bountiful moisture for the West and most Western reservoirs are in excellent condition. Even most of the reservoirs in the dry Southwest are in decent shape. With good water conditions in the Northwest, there will be enough water for hydroelectricity, the cheapest source of Western power. This also means that western agriculture, even California agriculture, should be allowed its full share of water without rationing.

The good news for the Southwestern states is that even though winter was dry, this part of North America, along with Western Mexico, is affected by the Southwest Monsoon. Typically, during the year following a La Niña, this monsoon’s wet season is strong. This would bring good rainfall for the Southwest from Arizona, through Colorado and western Nebraska, into West Texas and the Panhandle. Typically, the season lasts from July through September. It will be even stronger if the Pacific evolves into a warm El Niño, as almost a third of weather models predict.

The biggest problem that the South faces is that, unlike the West, many areas, particularly Texas, had multiple year droughts and severely depleted reservoirs. Texas, for example, had estimated crop and livestock losses of $7.62 billion last year. Even now, with a week of record-breaking rains and a damp winter, the state still has 87% of its territory in dry or drought conditions.

Expect the drought to break in Texas and the Southern Plains. It will take months to recover from the full devastation of the recent prolonged drought, particularly in the livestock industry. Historically in years with conditions like this, Texas and the Southern Plains are usually drought free by August. Crops are usually good, although it always takes Southwest Texas longer to recover than the rest of the state.

The Southeast, especially Georgia and northern Florida, has more difficulty recovering. The drought in this region was caused by both the La Niña and the normal patterns of the warm Atlantic. Remember the Southern “water wars” following the 2007/2008 La Niña. Even areas with normal rainfall had such severe reservoir shortfalls that the following summer saw rationingand legal battles. Expect many regions to have normal and near normal rainfall, but problems to remain because of high temperatures and high evaporation rates.

Meanwhile the drought in the Midwest should ease as spring progresses. However, most similar years have seen hot summers with reduced rainfall, particularly around the end of summer. Forty percent of those years had reduced farm productivity while most years had the region able to plant early and produce a good crop before the heat and dry weather became a problem. We are already seeing early planting. The current cold spell has damaged some crops, but a largely neutral NAO should restrain the damage to the Northeast and upper portions of the Midwest.

Overall, this year for US and Canadian agriculture looks as if it will be good, if not worry-free. The drought is easing and we are not facing the widespread flooding we have seen in the previous two years.

Europe

The same conditions that shaped the warm winter and spring in North America have caused freeze damage and drought in Europe. When the warped Icelandic Low shaped a strongly positive North Atlantic Oscillation (NAO), it shielded Europe from moist Atlantic storms. Instead, in February, cold, dry polar air poured into Europe from Siberia. The European Union that normally produces 20% of the world’s soft wheat lost at least 5 million metric tons of grain. It is estimated by Offre et Demande, that winter kill cut French output by about 2.5 million tons, Germany’s crop took a 2 million-ton hit, and frost destroyed 1 million tons of the grain in Poland. Rapeseed production was also hurt but the exact amount is still unclear.



Now the hot Atlantic is baking the continent with drought. The EU’s Monitoring Agricultural Resources unit reports that rainfall in Northern France, England and the north of Italy this year was 23 – 47% below average. The situation is worse further south, with rainfall 59 – 78 % lower than normal in Spain and France’s Mediterranean region. In the Balkans, the drought is reported to be the worst in 40 years and is forcing cutbacks of hydropower, the region’s main source of electricity.

Of all parts of the world, Europe is the most unaffected by the changes in the El Niño/La Niña cycles. It is also the most vulnerable to the changes in the Atlantic.

It has also been vulnerable to the weather changes caused by Icelandic volcanoes. Historically, crops have been below average in Western Europe following large eruptions. However, the last two eruptions, 1918 and 1947, were when Europe was involved in World War I and the problems after World War II. It is hard to draw conclusions based on agricultural output from those years.

There are several indications that the drought conditions will linger through spring, particularly for Southwestern Europe. While global food prices should begin to drop after La Niña ends due to improved planting conditions for North America and Asia, planting concerns in Europe may slow the price decline.

Overall, with the disappearance of La Niña in April, the Northern Hemisphere faces a better agricultural season than last year. However, the warmth of the Atlantic and the lingering impact of Grímsvötn’s debris in the stratosphere will continue to create concerns around the Atlantic Rim, particularly in the Southeastern US and Southwestern Europe.

Source: Browning Newsletter

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