Category: Elsewhere in Weather News

Elsewhere in Weather News: April 20th, 2013

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Major Trough Moves through US

A trough of low pressure moving across a large swath of continental United States this week has been the cause for severe flash flooding, much wind damage, and a few tornadoes including Canada’s first of the year.

The first severe weather day occurred on Wednesday, April 17th, when a moderate risk was issued by the SPC for most of Oklahoma, parts of south-west Kansas and Missouri. Over 150 chasers (reporting) were scattered throughout Oklahoma, and at one time over 50 chasers could be seen on the same supercell! Severe thunderstorms fired along the warm front and further along the dryline that extended into Texas in early afternoon. The storms that had the largest tornado potential went up in south-western Oklahoma and moved towards the north-east. These storms along the warm front trailed each other and produced flash flooding in some localities. Also to note is that a few cities such as Lawton, OK who were lying along the warm front saw not one supercell that day, but three within four hours. One of these also dropped a tornado which caused some damage to an industrial area on the outskirts of the town.

Chasers

Incredible chaser convergence (red dots) in Lawton ahead of a supercell. Just about every single street in Lawton had a chaser on it! (Source: Spotter Network/RadarScope)

On Thursday and Friday the trough continued its push eastward, but it became less of a tornado threat and more of a severe wind and hail event. At one time, thunderstorms stretching from Ontario all the way down to Texas could be seen. A few states such as Illinois, Iowa, Alabama, and Missouri saw extremely heavy rain in a short period of time which was cause for flash flooding concerns. Air rescues took place in Oxford, Alabama to save stranded motorists caught in their partly submerged cars. Canada’s first tornado of 2013 was also recorded on Thursday, rated as an EF 1 it touched down near Melanchton, Ontario.

Tornado damage

Damage of a barn in Southern Ontario from the EF 1 tornado. (Source: Steve Murphy EMC via Caledon Enterprise)

The cooler weather is not expected to last this weekend as return flow sets up and southerly winds kick in for most of the Plains and Midwest. Later next week it appears as though yet another high pressure will slide down the Rockies, in turn bringing more unseasonably cold air to the Central United States.

Elsewhere in Weather News: April 6th, 2013

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Historic Flooding in Argentina

Major cleanup efforts are underway in Argentina this weekend after major flooding occurred in the city of La Plata (pop. 250,000), just east of Buenos Aires. In some areas of La Plata, over 150mm fell in less than a 24 hour period causing for some flash flooding when the city’s sewers simply could not keep up. The reason for so much rain over one area can be attributed to a nearly stationary low pressure system over Argentina, south-west of Buenos Aires. Moist air from the South Atlantic was drawn in and the near stationary thunderstorms stayed over La Plata for over ten hours, beginning April 1st, lasting through April 2nd.

La Plata flooding

Aerial image of one of La Plata’s hardest hit areas. (Source: Reuters)

Flooding caused whole neighbourhoods to be submerged and people had to escape from their houses through the roof as floodwaters rose up to three feet. At one point, three million people were without power across Argentina because of the heavy rains. Some 2,200 residents of La Plata had to be evacuated. Unfortunately, 54 people have died from this event and there are still around 20 people missing. The property damage is extensive and is still being calculated but is likely to be in the hundreds of millions.

Elsewhere around the world:

  • There has also been severe flooding in Eastern China and Taiwan due a series of low pressure systems that brought heavy rain to an already saturated soil base.

  • This week will likely bring another multi-day, severe weather outbreak in the southern half of the US; from the Southern Plains into Dixie Alley, as a large trough digs across the region and warm, moist air from the Gulf of Mexico clashes with it.

Elsewhere in Weather News: March 30th, 2013

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Europe Battles Cold

This past month it has not only been Southern Manitoba dealing with pesky cold Arctic air lingering around while the spring thaw should be starting up, most of Europe has also been under significantly below normal temperatures for the month of March. What has been bringing such cold weather can be attributed mostly to the same reason why we’ve been getting such cold; a negative NAO (North Atlantic Oscillation) pattern. This is cause for Scandanavian highs staying put and bringing down some unseasonably cold air from the north-east in Europe’s case.

NAO

Graph of the NAO showing values of below zero for the whole month of March. (Source: NCEP)

Germany has had the worst of the cold in Europe with their average March temperature 4°C below average – the coldest ever since record keeping started in 1883. Other parts of Europe were generally 3°C below average for March. To add to the cold temperatures, Europe has been faced with a few significant snowstorms this month, such as last week’s snowstorm that caused hundreds of flight cancellations and even the closure of Frankfurt’s International Airport. The reason for these significant snow events this late in the season can be attributed to a low pressure system drawing in moist air from the North Mediterranean. This, when combined with the stationary Siberian high feeding cold air into the northern half of the low, makes for ideal snowy conditions.

Low pressure system, Europe

Low pressure system making it’s way across Europe and bringing with it snow. Heavy snow in areas outlined in purple, thanks to cold air being brought down by the Scandanavian high.

The Scandanavian high looks to stay put over the region for just a little less than another week, however, with the NAO trending upwards and with the sun getting stronger every day (we are now at the equivalent of a September sun), this means that warmer temperatures are on the horizon for most of Europe for the second week of April.

Elsewhere in Weather News: March 23rd, 2013

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Damaging Tornadoes Touch Down Across the World

Tornadic activity was experienced across the globe this past week, affecting countries from Bangladesh to Australia and even China.

Australian tornado

Capture of the Doppler Radar velocity at the time of the tornado (area of dark blue vs. red). (Source: BoM/ @vicstormchasers)

In Australia on March 21st , at least two powerful tornadoes touched down on the border of Victoria and New South Wales, ripping through more than a half-dozen towns lying along the Murray River. The strongest twister, with an estimated F2 rating on the Fujita scale, caused major damage to the towns it swept through – tearing roofs off their structures, throwing cars around and snapping power lines. In total, 20 people were injured and two had to be airlifted to hospital. Thankfully no deaths were associated with this tornado outbreak. A deep low pressure system responsible for spawning these tornadoes lay just off Tasmanian coast with a cold front stretching up into Australia.

Video of the Australian tornado dangerously close up. Power flashes and debris can clearly be seen flying through the air. (Source: Daniel Clarke)

The tornado that touched down in Bangladesh on Friday, March 22nd also caused a fair amount of damage to a few rural eastern Bangladesh towns. The twister was on the ground for about 15 minutes but it is not yet known what the strength of the tornado was estimated to be. At least 100 injuries and 20 deaths were reported as a result of this tornado.

The people of Bangladesh are more susceptible to injury and death from tornadoes since finding a safe haven from them is not as easy as heading down to a basement to take cover. Most houses in the area are built out of mud and don’t have a sturdy structure, making it difficult to escape when residents find themselves in the path of a twister. Tornadoes are common in Bangladesh from March to late April before they transition into the monsoon season.

Guangdong, a southern province of China, was also in the crosshairs of severe weather this week. A supercell produced egg size hail accompanied with a tornado that made its way through the city of Dongguan (pop. 400,000). Significant damage occurred – many buildings collapsed and the storm even overturned a ferry offshore. These Chinese storms were the deadliest storms of the week, accounting for 24 deaths and over 200 injuries.

China egg-size hail

Hail the size of eggs covers the ground in Dongguan, China. (Souce: I.B. Times)