Will we ever be able to forecast tornadoes?
Will we ever be able to forecast tornadoes such as the one that hit Greymouth last week? "Not in any great detail," says
MetService Weather Ambassador, Bob McDavitt, "but we are working towards being able to identify the regions where
tornadoes might occur."
"In the United States, where tornadoes can last longer than an hour and cause massive devastation, they have installed a
comprehensive network of powerful Doppler weather radars making it possible to detect the formation and track of
individual tornadoes. Even so, specific communities may only receive about 20 minutes warning of a touchdown."
McDavitt went on to say that tornadoes in New Zealand are usually very short lived, and most of them last less than ten
minutes. "Tornado intensity is measured on the Fujita Scale which ranges from zero to five, the most intense. Our
tornadoes are usually F0, but the Greymouth tornado was an F1 or an F2 and the fatal one that demolished a house near
Waitara last year was likely to have been an F4."
Although specific tornado warnings are not yet possible, MetService has begun issuing advice of severe thunderstorms.
"We now have a team of storm forecasters who are on the lookout for severe local storms that may produce torrential
rain, hail and damaging winds. Westland was identified last Thursday as a region for possible thunderstorms. We can't
give specific tornado touchdown forecasts. That would be like trying to forecast popcorn -we can say where the pot is,
but we can't tell which part of it will pop."
ENDS