{"id":4017,"date":"2023-04-11T03:33:02","date_gmt":"2023-04-10T15:33:02","guid":{"rendered":"https:\/\/thebuzz.apnanetwork.co.nz\/?p=4017"},"modified":"2023-04-11T03:33:02","modified_gmt":"2023-04-10T15:33:02","slug":"how-tornadoes-are-formed-and-why-they-are-so-much-bigger-in-the-us","status":"publish","type":"post","link":"https:\/\/thebuzz.apnanetwork.co.nz\/?p=4017","title":{"rendered":"How tornadoes are formed and why they are so much bigger in the US"},"content":{"rendered":"

The tornado or damaging wind that smashed through part of\u00a0east Auckland<\/a>\u00a0about 9.30pm on Sunday was associated with a line of thunderstorm clouds moving quickly from the west to the east.<\/p>\n

Such damaging winds could happen when thunderstorms were “particularly vigorous”, MetService meteorologist Dan Corrigan said.<\/p>\n

On Sunday night, the thunderstorm cells were lined up in such a way that they fed into each other and kept each other going.<\/p>\n

The weather feature that caused the damage may well have been a small tornado, but MetService was uncertain because it had not seen any photos or video that showed a funnel cloud reaching to the ground.<\/p>\n

“You can have strong down drafts out of thunderstorms that produce damaging wind gusts.”<\/p>\n

The risk of damaging winds was the same, regardless of whether they came from a small tornado or from gusts.<\/p>\n

Between 8.30pm and 9.30pm Sunday, the strongest gusts recorded in the Auckland area were in exposed locations – 96km\/h at the Tiritiri Matangi lighthouse and 87km\/h at Whangapar\u0101oa.<\/p>\n

Wind speeds at East T\u0101maki would have been much higher than that, Corrigan said, but he could not give a range.<\/p>\n

There is uncertainty about the number of tornadoes in New Zealand each year and it is thought some in remote areas are probably undetected.<\/p>\n

\"Erne<\/p>\n

Trees damaged in East T\u0101maki.\u00a0<\/span>Photo:\u00a0RNZ \/ Matthew Theunissen<\/span><\/p>\n<\/div>\n

But so far in 2023, two events thought to have been tornadoes have been reported in this country – in Greymouth in March, and at Waihi Beach in February.<\/p>\n

NIWA meteorologist Dr Richard Turner has said the typical number of tornadoes observed in New Zealand was roughly about seven to 10 a year.<\/p>\n

Some years had more, maybe as many as 20 or 30, but some of those would not have been observed.<\/p>\n

Based on observations and past studies, researchers thought areas of New Zealand most likely to have tornadoes were Taranaki, the West Coast, Horowhenua, and the Waikato coast.<\/p>\n

It is hoped researchers will get a better idea of the number of tornadoes in this country from a project under way at NIWA, where three decades of weather data is being run through powerful computers.<\/p>\n

Huge amounts of information is being produced, which will need significant analysis, but it is thought one output could be a better understanding of the tornado risk in different parts of the country, along with the changes in risk over time.<\/p>\n

\"LITTLE<\/p>\n

The damaged remains of the Walnut Ridge neighborhood is seen on 31 March 2023 in Little Rock, Arkansas in the US. New Zealand tornadoes are not nearly as large as those that cause massive destruction in parts of the US.\u00a0<\/span>Photo:\u00a0BENJAMIN KRAIN<\/span><\/p>\n<\/div>\n

Researchers could also look for factors that influence changes from year-to-year, such as the impact of La Ni\u00f1a or El Ni\u00f1o.<\/p>\n

NIWA described tornadoes as large rotating columns of air – a vortex – that happened in association with a thunderstorm.<\/p>\n

Tornadoes had winds that travelled at very high speeds around a central area of very low atmospheric pressure.<\/p>\n

The parent thunderstorms typically had very strong updrafts with speeds of 36km\/h, and which were developed in an environment that caused the updraft to rotate, potentially causing a tornado, NIWA said.<\/p>\n

Updraft speeds of more than 150km\/h or more had been reported in the United States but not in this country.<\/p>\n

In New Zealand, most tornadoes were associated with bands of thunderstorms embedded in a strong, unstable northwesterly flows ahead of a front.<\/p>\n

“The thunderstorms have very strong updrafts and if these occur in an environment in which the wind directions rotate counterclockwise as the air rises, the updraft can start to spin,” NIWA said.<\/p>\n

In those cases something called a mesocyclone – a rotating vortex that can be as small as 1-2km in diameter – could form, and it is from mesocyclones that tornadoes were spawned.<\/p>\n","protected":false},"excerpt":{"rendered":"

The tornado or damaging wind that smashed through part of\u00a0east Auckland\u00a0about 9.30pm on Sunday was associated with a line of thunderstorm clouds moving quickly from the west to the east. Such damaging winds could happen when thunderstorms were “particularly vigorous”, MetService meteorologist Dan Corrigan said. On Sunday night, the thunderstorm cells were lined up in […]<\/p>\n","protected":false},"author":6,"featured_media":4018,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[222,174],"tags":[],"class_list":["post-4017","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-latest-news","category-nz-news"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/4017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4017"}],"version-history":[{"count":1,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/4017\/revisions"}],"predecessor-version":[{"id":4019,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/4017\/revisions\/4019"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=\/wp\/v2\/media\/4018"}],"wp:attachment":[{"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thebuzz.apnanetwork.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}