Peter Webster at Georgia Tech is a colleague of Dr. Judith Curry.
Data generated by the European Centre for Medium-Range Weather Forecasting (ECMWF) in late July 2010 indicated imminent, extreme precipitation over Pakistan. Click here to see ECMWF Extreme Forecast Index maps and the centre’s newsletter article on rainfall predictions prior to the floods.
AGU Release No. 11–04
31 January 2011
For Immediate Release
WASHINGTON—Five days before intense monsoonal deluges unleashed vast floods across Pakistan last July, computer models at a European weather-forecasting center were giving clear indications that the downpours were imminent. Now, a new scientific study that retrospectively examines the raw data from these computer models, has confirmed that, if the information had been processed, forecasters could have predicted extremely accurate rainfall totals 8-10 days beforehand.
The study also finds that the floods themselves could have been predicted if this data, which originated from the European Centre for Medium-Range Weather Forecasting (ECMWF), had been processed and fed into a hydrological model, which takes terrain into account.
The July floods killed thousands of people and tens of thousands of cattle, and left large parts of Pakistan in shambles. The waters displaced, or disrupted the lives of, an estimated 20 million people.
“People don’t understand the powers of modern environmental prediction,” says Peter Webster, a professor of earth and atmospheric science at the Georgia Institute of Technology in Atlanta and lead author of the new study. “This disaster could have been minimized and even the flooding could have been minimized. If we were working with Pakistan, they would have known 8 to 10 days in advance that the floods were coming.”
He and his colleagues report their findings in a paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
The ECMWF, a London-based organization of 33 participating European countries, “does not give out weather forecasts and weather warnings to the general public or media,” notes ECMWF scientist Anna Ghelli. “ECMWF provides numerical forecasts to its member and co-operating states and they are responsible to prepare forecasts for the public and advise the authorities in their own countries.”
“We noticed that the signal was there five days in advance,” Ghelli recalls. However, the lack of a cooperating agreement between the forecasting center and Pakistan meant that these rainfall warnings didn’t make it to the Pakistani people, nor did Pakistan’s own meteorological agency forecast the flooding.
In their research, the Georgia Tech meteorologists use data from the European center to analyze whether or not the rainfall was above average for Pakistan and if the huge surges in the Indus River would have been predictable if flood forecasters were monitoring the country. They determine that, while the rainfall total for 2010 was slightly above average for the region, the July deluges were exceptionally rare, with rainfall amounts exceeding 10 times the average daily monsoon rainfall. They also find that if a flood forecasting model had been in place, the floods would have been predicted in time to issue warnings.
As a result of processing the raw output from ECMWF models from before the Pakistani deluge, the team achieves greater accuracy than the raw numerical forecasts alone provided. Some weather stations in Pakistan recorded nearly a foot (30 centimeters) of rainfall during the 4-day downpour. The after-the-fact predictions by Webster and his colleagues came in slightly below those amounts at the same locations.
Webster says that processing raw data into weather forecasts and combining them with hydrological models is only half the work. In order to have any effect, the resulting flood forecasts must be successfully disseminated at the village level, and local leaders must also understand them.
In nearby Bangladesh, Webster spent five years creating a flood-forecasting technique and organizing a cooperating agreement with the Georgia Institute of Technology, ECMWF, the Asian Disaster Preparedness Center and the government of Bangladesh. When flooding occurred there several years ago, warnings made possible by the forecasting pact not only averted loss of life, but also saved residents as much as $450 per farm — about the equivalent of an average annual salary in that country.
In a few weeks, Webster will attend an international meeting of developing nations in Bangkok to build support for flood forecasting in Pakistan. He says a forecasting system in Pakistan would cost a few million dollars to set-up, but as little as $100,000 a year once operational. He hopes to convince the World Bank, currently providing $1 billion of flood-recovery financing to Pakistan, to fund the project.
In Bangladesh, Webster recalls, an imam at a local mosque told him about how they discussed the flood forecasts each day in prayer. This is the sort of local solution that Webster envisions for Pakistan as well.
The National Science Foundation funded this research.
Notes for Journalists
As of the date of this press release, the paper by Webster et al. is still “in press” (i.e. not yet published). Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this paper.
Or, you may order a copy of the paper by emailing your request to Peter Weiss at pweiss@agu.org or Maria-José Viñas (mjvinas@agu.org). Please provide your name, the name of your publication, and your phone number.
Neither the paper nor this press release are under embargo.
Title
“Were the 2010 Pakistan floods predictable?”
Authors
Peter J. Webster, V.E. Toma and H-M Kim: School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia.
Data generated by the European Centre for Medium-Range Weather Forecasting (ECMWF) in late July 2010 indicated imminent, extreme precipitation over Pakistan. Click here to see ECMWF Extreme Forecast Index maps and the centre’s newsletter article on rainfall predictions prior to the floods.
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But…but….weather and climate can’t be predicted at all.
Right guys? Right?
Woulda, coulda, shoulda.
I think this is interesting and a real way in which modelling can be applied: short term predictions.
There are two facets required for such models to be useful. The first is a high probability of detecting an event when it is likely to occur. The second is a low false alarm rate. If the false alarm rate is too high, the forecast is useless.
I hope Dr Webster addresses these issues in the paper. I look forward to reading it.
“Now, a new scientific study that retrospectively examines”
=================================================
The best hind-casters money can buy………..
Not a one of them could predict anything if their lives depended on it.
You don’t think the U.S. is not in for some big flooding come spring?
Quite the pile of precipitation on the ground!
So all this money being wasted on looking for evidence of possible climate change that might cause loss of life, is more important than using existing technology to predict actual severe weather that really does cause loss of life.
Being a former weather forecaster I take papers like this with a bit of skepticism. The otherside of the coin is how many times have the forecast models been wrong? Being right a few times does not make a case (even if the models forecast a record weather event). One of the old rules of thumb forecasters used is never forecast a record event -especially past the H+24 period. If one does forecast a record event (temp, thunderstorms, etc…) you had better have solid meteorlogical reasoning other than what the models “say”.
It is one thing to make an accurate prediction but to suggest that they (Pakistan) could have controlled the flooding with 8-10 days notice is the height of lunacy. Pray tell how could they have diverted or stored the water to avoid this problem.
With Pakistans infrastructure I doubt 5 days extra warning would have made much difference, as it was the biggest critisism was for the civil Govt who just stood by, nothing got done until the army got involved.
“The July floods killed thousands of people and tens of thousands of cattle, and left large parts of Pakistan in shambles. The waters displaced, or disrupted the lives of, an estimated 20 million people.” Warnings and preparation were possible due to accurate computer models.
What great possibilities there are for “computer models” if they are used for scientific purposes which are then used to inform or warn people/societies. What monstrous possibilities there are when they are used to disinform and control people/societies.
Peter Webster says, based on information he got from ECMWF, that he could have told them 8-10 days in advance.
“We noticed that the signal was there five days in advance,” Ghelli with the ECMWF, says the signal was there five days in advance.
Peter is blowing smoke…………..
If he “could have” predicted it, why didn’t he?
Because he can’t………………
Given the death toll and hardship endured, this is bound to be inflamatory.
Even if such detailed forecasts were possible with sufficient certainty so as to warrant action, the underlying issue is the extent of reaction possible with just 5 or 8 or even 10 days prior notice. Given the infrastructure, it would seem to be a herculean task to evacuate the locals from that area. Certainly the deploymengt of effective flood defences and diversions would not have been possible on this time scale. It is probable that little mitigation would have been possible in the circumstances.
On a similar vein, there are similar issues over the Queensland floods. Some are saying that these were predicted 6 months in advance and in any event City planners had been ignoring flood issues as from the late 70s. There may well be a case that far more could have been done to mitigate the effects of those floods.
But, but by saving human lives and property you put even more burden on Mother Earth. It is surely an evil plot, this flood forecast thing, irresponsible interference with Holy Gaia’s self-defense.
/bitter sarc off
“Now, a new scientific study that retrospectively examines the raw data from these computer models, has confirmed that, if the information had been processed, forecasters could have predicted extremely accurate rainfall totals 8-10 days beforehand.”
Yea, but that’s not anyones job. Their job is convince the populas that we are all doomed from CO2. Its a full-time job and there is not time for anything else. Besides forecasting something 10 days out will not get you a research grant.
A little bit late to the show aren’t they?
Here is a prediction that is just is accurate….
A category 5 Hurricane will hit the Gulf Coast in 1969. It’s gonna be nasty, so get prepared.
Hindsight is 20/20. I am not impressed.
And how many similar computer driven predictions of catastrophe did NOT occur?
Cherry picking a possibly correct forecast after the fact is NOT science unless you include all data to show how many times you were right, versus how many times you were wrong.
Astrologer to prospective client: “I see you were born under a water sign, Pisces, and hence you are drawn to water. That’s why you married a Navy man. I could have predicted it!”. These kind of successful retroactive “predictions”, based upon computer simulation, are an old joke in the computer modeling field. Successful retroactive predictions are a dime a dozen. It’s really a modern “high-tech” variation on an ages old parlor trick. What is exceedingly rare are successful forward predictions.
Piers Corbyn on the floods in Pakistan (6 x 22 = 132 years, 7 x 19 lunar eclips cycle)
Why predict something beforehand, when you can always predict it after the fact?
Didn’t Piers Corbyn predict this well in advance.
I have some concerns here. The ECMWF is one of the best models and they are saying it predicted the precipitation up to 8 days out. That’s fine from a meteorologist perspective and easy to say in hindsight, but it’s a much more complex issue when it comes to real world implementation of this knowledge.
Let’s just say 5 days as one quote in this article said. What could have been done 5 days in advance to mitigate impact and how much would it have cost compared to what could have been saved? How often would actions like this need to be taken if the 5 day forecast was taken as verbatim? How often would those actions be right, wrong, and whatever shade between those two that can occur? How much would that cost and would spending money on 5 day forecasts protect enough property and save enough lives to be worth it over the long term?
My gut feeling is that 5 days forecasts can’t be used for all that much without wasting more resources in the long run than it would actually protect.
every country must have problem in floods especially tropic country
When I was a teenager, I used to go to the horse races with my mother. At one of those meets, a rather long shot won a race, and paid a ton of money. After the race, I told me mother; I was going to tell you to bet on that horse.
So Obama tells us we have the technology to get 80% of our energy from clean green free renewable sources.
So now we are told that the Pakistan floods could have been predicted.
Well it’s pretty obvious to me that they couldn’t have been predicted, because they weren’t. And when we get, and have systems in place that can predict such things they will get predicted.
So they already collect the data necessary to predict massive floods days in advance and they have the necessary computer models to process that data and make accurate predictions.
And for just a million dollars more and a few hundred thousand per year…
Gee you see storm brewing that will drop a foot of rain on you neighbor and because he doesn’t belong to the group you just buy popcorn and get a ring side seat. I’d be too embarrassed to then go publish a paper about it.