UN Geneva - Multimedia Newsroom : WMO Press conference

Good morning everybody.

Thank you for joining the press conference of the World Meteorological Organisation.

Today we are releasing a new update on on La Nina.

In my in, in the room with me on the on my left is Doctor Max Dilley, who is the Deputy Director responsible for climate at the World Meteorological Organisation.

On the far left is Gavin Eiley, who's a senior expert with WMO, responsible for coordination with the and building up the humanitarian response to, to, to this phenomenon.

On the line, we are joined by Wilfran Mufuma, who is the head of our regional climate prediction branch.

And for journalists who are Francophone Wilfran, he's available to answer any questions that you might have in French and indeed in English.

So without further ado, I will we we've sent everything out under embargo.

If you haven't received it, just let me know and I can resend it.

Thank you.

So without further ado, I'll pass the floor to Doctor Dilly.

Greetings.

Could I have the first slide please?

There we are.

So I'll just start by explaining briefly that La Nina is a cooling of the sea surface temperatures in the eastern and Central Pacific.

And as you see on the slide, this is what it looked like as a couple of days ago and some of you may have heard of El Nino.

La Nina is the opposite phase.

El Nino is a warming in that part of the Pacific.

But now you see in the La Nina case, a big part of the eastern and Central Pacific has gotten colder than usual.

This started occurring in August and September and this is what it looks like now.

Next slide, please.

And the next slide please.

There we are.

So moreover, there is a **** on the order of 90% probability of this condition continuing through January and it is also very likely to remain moderate to strong and strength, meaning sea surface temperatures cooler than average on the order of 2 to 3°C during that time.

Next slide please.

So why does this matter?

These warming's or in the case of the La Nina, the coolings of these large ocean areas have a significant effect on the circulation of the atmosphere that's flowing over them.

And the changes in the atmosphere in turn affect precipitation patterns around the world in in typical ways.

So this slide shows the typical regional effects of La Nina on precipitation.

And you see over the area of the Pacific, that's cool.

Now, there's a tendency for dry conditions and wet conditions in the surrounding area of the Pacific, but these atmospheric perturbations extend outside the Pacific region through what we call teleconnections.

So you see, for example, that there are tendencies toward wet conditions in northern South America, in dry conditions in southern North America, and also in southern South America.

And in Africa, there is a tendency towards wet conditions during La Ninas in the southern part of the continent.

But in the Horn of Africa you can see there's a tendency towards dry conditions and there are also, it's important which season it is.

The seasonality in southern Africa, where we have a October through March rainfall season coincides with the La Nina.

So it matters very much now over the next few months what the the actual anomalies, if there are any, will are going to be.

Some of the other regions where the season is just now getting underway are Central Asia and the southern tip of the Indian subcontinent.

So these are typical regional tendencies.

But every La Nina event, every El Nino event is different.

And moreover, there are other influences on regional climates besides what's happening in the tropical Pacific, perhaps quite far away.

So if I could have the last slide please.

So we therefore use a combination of global climate models in something called a multi model ensemble that take that takes into account not just the characteristics of this particular event, but also all of these other influences, sea surface temperatures in other oceans for example that affect regional climates.

And this slide shows what the outlook is for the globe for November, December and January the next three months.

So you can see that some of the pattern matches quite closely the typical La Nina influences.

We see this drying over anticipated over the La Nina area and and wet conditions in the surrounding parts of the Pacific.

And we also see in the Americas going from north to South, that sort of dry, wet, dry pattern from the northern to the southern hemisphere and also an likelihood of dry conditions in the Horn of Africa and in Central Asia.

And also so, so those are all consistent with what we would typically see.

Also the outlook, because it covers the entire globe, gives outlooks for regions that are not normally teleconnected with La Nina.

So you can see that there are dry anomalies in Eastern Asia, for example, but also there is an absence of an outlook for wet conditions in southern Africa, which is normally wet during La Nina's.

And this latter discrepancy really highlights the need to monitor the updates throughout the season and also to consult the regional climate outlooks from the WMO, regional climate centres and Regional climate outlook forums, but also even more importantly from the national Meteorological and hydrological services.

So I'll just close by saying a word about what is done with this type of information.

So the regional and national outlooks like the one we looked at for the globe are disseminated to a wide range of stakeholders in each country through the the national meteorological and hydrological Services.

And that information is used and we have documented evidence that it is being used for decisions in the agriculture sector, water resource management, to anticipate and manage increases in the incidences of waterborne or vector borne diseases and even for energy.

Hydropower of course, is very sensitive to these types of variations in in climate from one year to the next.

And then in some cases when these anomalies become extreme, they can trigger disasters.

And so there's a a big application in Disaster Risk Reduction.

So from the WMO point of view, at the international level, we are increasingly providing this information to the United Nations and international humanitarian organisations that use it to plan their support for prevention and preparedness and response in some of the countries that may be experiencing adverse impacts.

So I'd like to just turn the word over to my colleague Gavin, who will explain a little bit more about the international use of the forecasts.

Thanks for that, Max.

Just to elaborate a little bit on how we've been supporting our humanitarian colleagues both and from the UN family as well, both here in Geneva and New York and elsewhere.

As Max reference from a WMO perspective, the Med services, hydromed services around the world are a rich source of information, both from a a weather forecasting perspective, but also in terms of potential impacts from events such as Linenia.

So over the last two or three months or so, through the guidance of the UNS Food and Agriculture Organisation, we've been set at what's called the Cell team, which has come together to assess the impacts of what this particular event may mean.

And assimilating information.

Not just the information, but information from food security, economic perspective to try and assess which areas of the world may actually be the ones that see potential impacts.

So not just as Max's reference from La Nina, but from a more from a humanitarian perspective.

And that group has been meeting frequently over the last two months.

From a Met perspective, we have W Moore, we have the World Food Programme and Columbia University discussing what our perception is of the of the the global forecasts and the information from the Met services.

That then gets overlaid with lots of other information until we're able to come up with a collective decision in terms of which areas we think perhaps most impacted that.

Then the beauty of that system is that that gets briefed across the UN, both it's sort of head office level, but also regionally so that there we can start seeing anticipatory action rather than act after we can start putting actions in place.

And another element of that has been with a a longer term of sort of a six month horizon scanning that we do this time under the chairmanship of the World Food Programme, looking to assess the nine year impacts, how that might affect the sort of the global hotspots as such well into next year.

And all of this and the work that we've been doing within or WM OS been doing within this arena is the, the realisation much more that, you know, the natural environment information can actually be really put to good use.

It's not necessarily always bad news.

And if we harness that, we can actually start making decisions.

And there's lots of really good examples of where that takes place.

And W and Moore now is trying to move forward and create more effective coordination mechanism where we can pull through this expertise from our members on a more regular and a more structured basis to help support our UN colleagues and other humanitarian colleagues.

So I'll leave it at that for the time being, but happy to take any questions.

Thank you very much.

And just to put it in context as well, the last time that we had a La Nina of a what we think is comparable strength was 10 years ago, so back in 2 thousand 2010, right.

If there's any questions, please could you.

There's obviously nobody in the room, but if you could indicate yourself remotely so I can give you, I can give you the floor.

I think I've been unmuted.

Yes.

Claire.

Yeah.

OK.

Lisa.

Lisa Shine of Voice of America.

Yeah.

Hi.

I one of my great strengths is that I'm willing to admit that, admit my stupidity.

And I'm afraid I've got lost in the thicket of your technical explanation about what is happening in the forecast of the, the La Nina continuing into next year.

So perhaps you could simplify things.

What I'd like to know is I'm not really quite sure whether we, I, I gather that some parts of the world will be wetter and some drier than normal.

So if you could simplify it and tell what are the main Hots, the major hotspots you Mr Ily, I believe it is refer to major hotspots and you were speaking about the the humanitarian impact of what is likely to occur in these areas.

I'm particularly interested in the situation in Africa.

If you could talk about that, Are you essentially saying that some parts that should be wetter are going to be drier and that the in reverse is also true?

As you can see, I live up to my reputation of stupidity.

So and also what is this going to mean in terms of food production and increase in hunger and your solutions And the reason why I'm I'm because it's Zoom.

That's why I'm I'm bludgeoning you with so many questions at once.

Thank you.

Thank you, Lisa.

And you're not ******.

They're very good questions.

So perhaps I will pass it to Doctor Dilly to deal with the first one and then to, to Gavin Eiley for the for the follow up.

Yes, Lisa, you're, you're not ****** at all.

You, you got the point, which is that indeed, when we have a La Nina, there are parts of the world that become drier than they normally would be or wetter than they normally would be.

And we went through the map.

I won't go through it again, but you saw the pictures for yourself.

And when this happens, as you rightly said, and as I also mentioned, it has impacts on on many sectors.

It has impacts on agriculture, as you mentioned, but also other sectors that are very important for society.

Now, how much of an impact it has is not just a function of rainfall, it's also a function of how vulnerable a particular region is to the degree of change in the normal climate that they would expect they're subjected to.

So when you have regions in Africa that are already experiencing difficulties with food security or human health or other sort of stresses that they may have.

And then you have one of these sort of changes in the in the rainfall that from what's normally expected, those those situations can become even more acute to the point where they can even become emergencies.

So that was the main point.

And I think you more or less did indeed capture it.

I'll just turn over to Gavin to say something about what the humanitarian community has been following most closely.

Thanks Max, and thanks Lisa for the question.

I, I don't call them ******, I call them very nice questions for someone like me to understand.

So thanks for that.

In terms of the areas, the vulnerable areas from a humanitarian perspective, what I'm not going to comment on are the specific impacts on the ground because they are the areas from the Food Agriculture Organisation or World Food Programme, they are the experts to comment on that.

But what I can comment perhaps is on some of the areas that would have been raised for concern.

So certainly the Greater Horn of Africa, as we know, it's already been beset by problems with locust infestation and generally the models are suggesting below normal rainfall for quite a large portion of the Greater Horn of Africa.

So obviously that could have a number of impacts, but as I said, we're not necessarily going to go into that.

It's interesting, although we say we must monitor the sort of latest seasonal forecasts in areas like Somalia and South Sudan.

Of late there's been quite a lot of rainfall, in fact flooding in some places.

So we always need to keep an eye on the the sort of latest outlook.

South Africa, as Mark said traditionally would see, should see above normal rainfall.

The jury's still out on that.

And that's an area that we have to be looking at very, very carefully as we go forward.

Other areas of concern from a humanitarian perspective, Central Asia across into Afghanistan as as we know Afghanistan's very vulnerable for a number of reasons.

And then further into Southeast Asia where it looks and into a lot of the Pacific islands where looks to be above normal rainfall.

And the forecasts are quite confident on that and what that might mean on the ground from flooding, potential landslides or wider humanitarian issues.

So there could be a number of factors at play there.

Hope you forgive me for not answering the the non meteorological questions and deferring those to our more able humanitarian colleagues.

Thank you.

And obviously at the moment in Southeast Asia, Vietnam seeing very bad flooding worsened by a recent typhoon.

Are there any more questions?

Hi, can you hear me?

Yeah, OK, because because I have I have a follow up.

Yes, yes, thank you.

OK, then how, how can a nation's best utilise the forecasts in order?

Because these forecasts would, would essentially give them an early warning as to their need to take various actions.

So how can they best use this in order to prepare for a drier season or a wetter season?

And how long is this La Nino likely?

To last into next year and I don't know if you have anything to say about El Nino, whether that gets mixed dangerously into the mix?

Thank you.

So how the countries use the information is depends on which sector is of concern for different groups of of stakeholders.

The I'll just use a a couple of specific examples.

Let's take hydropower which I mentioned.

Some of the regions that we talked about have a very **** degree of this inter annual variability where you get a La Nina and it gets wet or it gets dry and then you have an El Nino and the opposite happens.

And so the managers of hydropower installations have to try to balance the amount of water that they store in a reservoir system to generate power and for drinking water and for flood control with the risks that if there's too much water, then they'll have to release water.

And this can cause flooding.

So you can have situations where the anomaly is so negative, meaning it gets so dry that these reservoirs stop producing power entirely, which obviously has major impacts across industry and across society generally.

But also you can have cases where the reservoirs fill right up to the top and then they have to spill lots and lots of water and you have major humanitarian issues all the way down the river system below.

So this is a case where when you have a forecast like this, the the dam managers can calibrate the amount of water that is retained or spilled so that it's not all done at once.

And if there are going to be shortfalls, there can be measures to conserve water or to reduce power consumption so that you don't get into sort of blackout situations and water scarcity.

So, you know, I won't go sector by sector, but you can imagine in the agricultural sector that, you know, some crops will do well under wet conditions and others will do better under dry conditions.

And there are agricultural management practises that can be adjusted to take account of whether it's expected to be wet or dry.

And so even at the farm level, farmers are able to use this information to, to try to optimise the way they manage the, the, the crops and try to get the best outcome possible under the expected conditions.

So we, you know, the, it's a very interesting area.

And what we're increasingly doing is trying to tailor these forecasts to forecast the specific variables that matter for these different sectoral applications.

You get outbreaks of dengue fever and malaria when you have very wet conditions in some cases.

But it's not just moisture, it's also temperature and humidity and even vegetation because that's what gets the mosquitoes going.

So rather than just give a rainfall forecast, we give a forecast of an index that's very highly correlated with malaria, and this can be used for malaria control.

You want to add anything just I suppose one point and really it's the, I think the word you mentioned there, Lisa is early warning and that early warning can be across multiple time scales from immediate to perhaps something that we should be concerned about in six months time.

A lot of agriculture is based off irrigation.

In some parts of the world, that irrigation is driven by snowmelt and actually accumulation of snow over a winter might not actually impact until six months later.

So it as Max said, it's that taking that that metrological element and then overlaying it with lots of other factors and what actions can governments take and what actions can people take?

Sometimes it might just be moving an action forward a few months that was going to happen anywhere.

Sometimes it might be a different type of crop to be grown.

Sometimes it might be insurance products.

So there's various actions that can be triggered and the key is taking that meteorology and overlaying it and meshing it with lots of other information until we get some advice that is really useful and can be acted upon.

Thank you.

And La Nina also does have an impact on tropical cyclones in different parts of the world.

And you know, having knowing in advance about La Nina does help planning for tropical cyclones.

I now have Nina Lawson from AFP French news agency.

Yes, Hi.

Can you hear me?

Sorry, Can you hear me?

Yes.

OK, thanks.

Thanks for taking my question.

I just I wanted to ask, this has been a very busy hurricane season and I know that La Nina and El Nina are not necessarily don't contribute directly to hurricanes.

But I was wondering if there is some sort of some sort of connection there, if you could, if you think that La Nina will will strengthen the Hurricanes or lessen them, if you could give us some sort of indication of that?

Thank you.

Yeah, thank you for the question.

And in fact, there is a connection between El Nino and La Nina and hurricane frequency.

El Nino tends to suppress hurricanes and and La Nina tends to sort of encourage them.

So if we do have a strong hurricane season, the La Nina could be contributing to that.

I also maybe I should come back to the question that Lisa asked about El Nino.

These this oscillation back and forth between the two La Nina and El Nino is on a more or less five to seven-year cycle.

So right now the probability of an El Nino happening this year is is negligible.

It's basically 0 next year.

It's unlikely that you would have an El Nino so quickly back-to-back with the La Nina, but it has happened in the past.

So each year is different.

But right now it's it's La Nina.

And these are always the more or less the same time of year, the fall and and winter season in the Northern Hemisphere.

So for right now, La Nina is definitely expected to be the prevailing condition.

OK.

And now Peter Kenny from South African Media.

Yes, please.

Thank you for taking my question.

I'm asking about South Africa and Southern Africa.

South Africa's Western Cape area, which is a winter rainfall area, has had considerably more rainfall this year.

And I'm just wondering if it can be attributed to La Nina and also going back eastwards to the other parts of Southern Africa, including Mozambique and other parts of South Africa, which have our summer rainfall areas and were heavily affected by the cyclones Edye and Kenneth Could.

Could those areas have big cyclones again, do you think?

I mean, you know, is there any way that you can look forward and see that maybe those are building up?

So the, the rainfall that you mentioned in Southern Africa is, is very consistent with the typical effects of La Nina.

So if this continues, it would not be a surprise given that that's very often the case.

But the the big seasonal impact effect of La Nina in Southern Africa is really from November through April.

So the this particular event is expected to continue through January.

After that we'll see.

But phenomena that happened in other parts of the year are more affected by other influences than they are by what's happening in in the Pacific.

So right now, the November through January, we would expect wet conditions.

The forecast is a little bit more ambivalent than on the classical pattern.

And that's why I think this is a something to keep a close eye on in that region is is when more information becomes available as we move through the season, we may see a stronger signal than we currently do.

Lisa is coming back for for seconds.

OK.

Lisa Shrine, Voice of America.

Yeah.

Hi.

I'd like to ask you specifically about the United States.

It has it has had a terrible hurricane season so far.

They've run out of the Roman letters and so they've gone Greek.

Is this likely to increase and intensify?

Do you have any idea how long this will be going on?

Will it go into next year as well?

Thank you.

The hurricane season is basically in the, in the Caribbean, which is where the Hurricanes that affect the United States and that whole Caribbean region come from is well from the Atlantic is from June to September and October.

So we're more or less now reaching the end of the season.

The season is is slightly extending.

It used to be really over in October, but now because the there's an overall warming of the oceans, there's more energy available for hurricanes later.

So we're seeing a few more perhaps in in the latter part of the season than was previously the case.

But from now on, we wouldn't expect to see any more hurricanes until affecting the US until next summer.

Rather what we would anticipate and you saw that in both the classical La Nina patterns as well as in the outlook from the models is that the Southern Tier of the US generally expects and I should say also northern Mexico.

Normally we would anticipate having drier than normal conditions for the next three months at least.

So it may go from hurricanes and flooding to dry conditions sort of fairly quickly.

Yeah, at least we are currently Hurricane Zeta is impacting the United States.

The next on the list, as you say, we're working our way through the Greek alphabet is ETA.

If we do have a tropical storm named ETA, that would be the first time on record that that that has that has indeed happened.

OK.

I can't see anybody else wanting to ask a question, so I'll if you do have anything to say.

No.

OK.

So thank you very much indeed for taking taking part.

As I said, if there are any interview requests in French, we can we can accommodate them.

And with that, thank you very much indeed for UN Television for hosting this and have a good day everybody.

Thank you.

WMO Press conference - El Nino, La Niña 29 October 2020