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Wullie Davidson’s Blog: Extreme Global Weather Events of 2021

Global Cooling Effect of the Ongoing La Nina Event

The global cooling effect of the ongoing La Nina event in the tropical Pacific means that 2021 was ‘only’ the sixth warmest year, globally, in a record going back to 1880. The El Nino Southern Oscillation (ENSO) has two phases, the warm El Nino, which boosts global temperature, and the cool La Nina, which has a cooling effect. A transition to ENSO neutral conditions is predicted by the spring. The last seven years have been the warmest years in the record.

Four Extreme Weather Events

For the first time, there were four extreme weather events, each costing more than $20 billion in damages.

1. Hurricane Ida (US Aug-Sep) $65 billion

2. European floods (Germany/Belgium July) $43 billion

3. Chinese floods (June/July) $30 billion

4. Freezing winter weather (US Feb) >$23 billion

US Winter Weather

The Arctic has warmed by three times as much as the global average, and this has caused the giant waves of the polar jet stream (Rossby waves) to plunge further south, bringing unusually frigid conditions to regions unused to it. This was the cause of the freezing winter weather in the southern states of the US in February, with Texas bearing the brunt. Temperatures in Dallas were as low as -19 C. 4.5 million businesses and homes were without power for up to two weeks, and there were an estimated 700 fatalities.These anomalously large Rossby waves also bring unusually warm weather when they return northwards to the Arctic, bringing warm tropical air to normally cold temperate latitudes.

The $23 billion price tag for the US winter weather may be an underestimate. Wikipedia gives a scarcely believable figure of $195 billion. There can be huge differences in damage estimates, due to different ways of accounting. The Federal Bank of Texas estimated that the financial losses for just the state of Texas would range from $80 to $130 billion. This includes ‘projected’ losses.

July European Floods

European Floods 2021 https://upload.wikimedia.org/wikipedia/commons/7/75/2021_European_Floods.jpg

The July European floods were the costliest weather disaster ever to hit Europe, with a death toll of 242. Such a high death toll from flooding is not unusual in tropical regions, but no one imagined that this could happen in western Europe. Scientists blamed the jet stream, as its west to east movement has slowed down considerably, due to the warming Arctic. This means that weather events associated with it have become more protracted. Heavy rain that may have lasted for a day or two in the past, can now persist for several days. This also applies to heat waves and cold spells.

Unprecedented Heat Wave in Western North America

NASA Earth Observatory/Joshua Stevens, Public domain, via Wikimedia Commons

However, the most remarkable weather event of the year occurred in late June, when western North America experienced an unprecedented heat wave. ‘Unprecedented’ is putting it mildly. According to weather historian, Christopher Burt, “This was the most anomalous regional extreme heat wave ever to occur anywhere on Earth since temperature records began. Nothing can compare.”

Again, the jet stream was implicated, forming a persistent ‘Omega block’ of high pressure, centred on British Columbia. The name ‘Omega block’ derives from the shape formed by the polar jet, which resembles the Greek letter, Omega (Ω).

A new temperature record of 49.6 C (121 F) for Canada was set in the village of Lytton, BC, obliterating the old record of 45 C, set in Saskatchewan in 1937. The following day, Lytton was destroyed by a wildfire. Such a high temperature would be an emergency in the hottest countries of the world, yet it occurred on the same latitude as London. Weatherwise, it’s clear we’re not in Kansas, any more. It’s estimated that the heat wave caused around 1,400 excess deaths.

2021 Atlantic Hurricane Season

NWS New Orleans, Public domain, via Wikimedia Commons

The 2021 Atlantic hurricane season was the second most active on record, with 2020 being the most active. 2005, the year of Katrina, was the third most active. 2021 was the seventh consecutive year in which a named storm formed prior to the official start of the hurricane season, on June 1.

Hurricane Ida was by far the most destructive storm of the season, causing 161 fatalities. It affected Venezuela, Colombia, the Caymans and Cuba, before making landfall in Louisiana, where its 150 mph winds caused the most damage. After landfall, it traversed the US to New England, where it stalled, causing $20 billion in damages, mostly from flooding. It was the costliest storm to hit the northeast region since hurricane Sandy made landfall in New Jersey in 2012.

Other Notable Extreme Weather Events

Super typhoon Rai made landfall in the Philippines in December as a category 5 storm, with 160 mph winds. Landfalling category 5 storms are rare, but Rai was the third such storm to hit the Philippines in the past two years. Super typhoon Chanthu made landfall in September, with 165 mph winds, and in November 2020, super typhoon Goni hit with 195 mph winds, making it the strongest landfalling tropical cyclone in world history.

Hannes Grobe 20:10, 16 December 2007 (UTC), CC BY-SA 2.5 <https://creativecommons.org/licenses/by-sa/2.5>, via Wikimedia Commons

For the first time on record, rain fell on the Greenland Peak (9,800 ft) on August 14.

In July, 800,000 people were displaced by floods in South Sudan.

In August, an unprecedented area of wildfires consumed forests in Siberia and the far east of Russia, following record breaking heat and drought. For the first time known, smoke reached the North Pole, 1,800 miles distant from the fires.

Wullie Davidson, January, 2022

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