The art and science of weather forecasting and why we can’t predict Mina

Our weather forecasters have drawn a lot of undeserved flak for the way Mina has skirted the areas she was supposed to damage. We must be so cynical we can’t even recognize good news.

From the Philippine Daily Inquirer is this report: Mina’s veering off sparks text jokes in Albay. We hope you don’t mind if we’re occasionally serious.

But first a joke from Onionista. Typhoon Mina changed course, from B.S. Meteorology to A.B. Political Science and she’s now in Malacañang meeting with Gloria, Cerge Remonde,Ronnie Puno, and Ignacio Bunye, trying to spin the whirlwind and grab credit for the minimal destruction thus far.

Now for the serious weather jokes:

1. “I am not sure how clouds get formed. But the clouds know how to do it, and that is the important thing.”
2. “In making rain water, it takes everything from H to O.”
   
3. Water vapour gets together in a cloud. When it is big enough to be called a drop, it does.

Here’s the source of these corny jokes,

Now this is the source of the serious stuff. There are two mainstream methods in weather forecasting.

1. The persistence method:This is the simplest way of producing a forecast. The persistence method assumes that the conditions at the time of the forecast will not change. For example, if it is sunny and 87 degrees today, the persistence method predicts that it will be sunny and 87 degrees tomorrow. If two inches of rain fell today, the persistence method would predict two inches of rain for tomorrow.
2. Numerical Weather Prediction: Numerical Weather Prediction (NWP) uses the power of computers to make a forecast. Complex computer programs, also known as forecast models, run on supercomputers and provide predictions on many atmospheric variables such as temperature, pressure, wind, and rainfall. A forecaster examines how the features predicted by the computer will interact to produce the day’s weather. The NWP method is flawed in that the equations used by the models to simulate the atmosphere are not precise. This leads to some error in the predictions. In addition, the are many gaps in the initial data since we do not receive many weather observations from areas in the mountains or over the ocean. If the initial state is not completely known, the computer’s prediction of how that initial state will evolve will not be entirely accurate. Despite these flaws, the NWP method is probably the best of the five discussed here at forecasting the day-to-day weather changes. Very few people, however, have access to the computer data. In addition, the beginning forecaster does not have the knowledge to interpret the computer forecast, so the simpler forecasting methods, such as the trends or analogue method, are recommended for the beginner.

Weather forecasting shares some characteristics with economic and political forecasting. The forecasters never get sued.

You might be wondering why we’re in a good mood. We just got over a persistent tropical depression. Smile naman.

Philippine ‘typhoon corridor’ bill breezes thru House on third reading

Manila–Fearing the consequences of typhoon Mina (international codename Mitag; click here for real-time tracking), the House approved without a vote on third reading a measure creating the Philippine ‘typhoon corridor’ at four this morning. House Bill 999.9 sponsored by Rep. Perpetuo Quixote of windswept Batanes had been certified as urgent by Malacañang, allegedly to calm the political weather.

Deliberations of the public works committee had earlier been described as stormy, and before news of Mina, discussions had just been going round and round in circles and spirals.

The measure, mandating the use of state-of-the-art weather control technology, not only eliminates all damage from tropical disturbances but also quadruples the country’s wind energy potential to 16 gigawatts, proponents said. In addition, it would also help shed the country’s image as a state of calamity.

Gloria Macapagal Arroyo, alleged Philippine president, lauded the development but warned of difficult negotiations in the bicameral conference committee because of radically conflicting provisions. Hearings on the senate bill have also frequently been cancelled because of bad weather.

The corridor, to be constructed at an estimated cost of anywhere from P55 billion to P1 trillion, will be financed in the main by official development assistance from China. It will thenceforth be the sole authorized passageway for all typhoons through the country, and will be administered by the National Disaster Coordinating Council (NDCC). The infrastructure project will be the first of its kind in the world, NDCC spokesperson Anthony Golez said.

The House version envisions the corridor to be carved across valleys and mountains 20 kilometers south of the northern tip of Luzon. The counterpart bill in the upper chamber, sponsored by senators Aquilino Pimentel and Miguel Zubiri, wants the corridor to cut the whole country longitudinally, from Davao, zigzagging through the major cities in Mindanao and on to the Visayas and Luzon. The House version provides that displaced residents would be relocated to Taiwan while that of the Senate designates Malaysia and Singapore. Both versions provide for the establishment of wind farms along the breadth of the corridor under build-operate-own (BOO) arrangements.