El Nino could bring droughts, floods

Transcript

Climate Scientists are warning some Pacific countries to prepare for possible droughts as an El Nino pattern is likely to develop across the region by Spring.

The latest Island Climate Update says atmospheric conditions are indicating the development of El Nino, which will bring higher than normal rainfall to some areas, and lower than normal rainfall to others.

A Climate Scientist at New Zealand's National Institute of Water and Atmospheric Research, Andrew Lorrey, told Jamie Tahana that while it doesn't look like it will be severe, some areas should prepare for water shortages.

ANDREW LORREY: Any type of El Nino event can be widely varying and different, but typically if you look across the Pacific there's a large-scale change in both the ocean and the atmospheric circulation that occurs and it typically brings wetter than normal conditions to some places, and dryer than normal conditions to other places. In the case of El Nino events, islands to the west of the date line; places like Fiji, Vanuatu and New Caledonia, typically end up with dryer than normal conditions during an El Nino event, whereas certain areas to the east of the date line; even those parts around Samoa, although Samoa can be a bit variable, but places like Tuvalu, Tokelau and the northern Cook Islands typically get wetter than normal.

JAMIE TAHANA: Wetter than normal, dryer than normal. Is there any way of indicating kind of how much so? Whether we're looking at droughts, massive flooding or anything?

AL: Yeah, I mean drought's a tricky one because it's defined differently in different circles of influence and it also depends on the conditions leading in to the time when El Nino tends to lock in, which is right around the onset of Austral Spring. So for instance, like New Caledonia; if we look back at the historical rainfall for the last couple of months there's been either below normal or well below normal rainfall there since March. So because of that and because of the fact that we are going into the austral dry season right now, well we're in it right now, and we have this development of El Nino, that could spell a bit of trouble for a place like New Caledonia. There are several other countries that have a bit of a mixed bag in terms of the rainfall that they've received in the past month so for every place it's a bit different.

JT: And from this forecast, if we look at them previously in a kind of pattern, can we see things emerging?

AL: Yeah, I mean you can see typically a few things emerging from the forecast. The first situation is that the international climate forecast community seems to think that we will have El Nino with us by the onset of Austral Spring. So [by] the beginning of September we should have an El Nino event. Now it doesn't look like right now it's going to be a super event and we say that because the oceanic component of El Nino appears to be close to threshold but the atmosphere is really yet to respond and it normally would have had to have responded by now and be locked in with the ocean in sync in order to get a really big event. So this might be a moderate event that's coming up in the Spring. But again, it shouldn't be taken lightly, you can have varying effects of that type of event that can be quite severe for some places and there can be significant water shortages that are expected for some of those places. For small island nations which have tank water largely as some of their supplies, especially in outlying island areas, that can be something that we really have to keep our eye on particularly because the effects of this can be quite acute and they can come on quite quickly.