Southern Nigeria has been experiencing an unusual rainfall pattern this year. July ought normally to be the peak of the rainy season, but it never happened. In contrast, the northern part of Nigeria has been experiencing more rainfall, leading to flood in some towns.
What is responsible for this? TheNEWS asks the expert at the Nigerian Meteorological Agency: is why.
John Chigbu:
“We have had the first phase of the rains over the South West and we are still expecting to have the second after the break we are now witnessing. By the end of this month, or even before then we will enter the second phase of the rainy season. During this period, we will still have normal rains, but that does not rule out the possibility of flooding”
John Chigbu, General Manager at the Weather Forecast Office at the Murtala Mohammed International Airport , Lagos speaks on current rainfall patterns
Q: Is it possible to accurately predict rainfall pattern and levels at the beginning of a year?
A: That’s what NIMET does. NIMET predicted late onset of rains and early cessation this year. We make use of data for our predictions. We have a lot of meteorological observation being issued in all the 36 states of the federation. In some states, we have more than one centre where this is done. These stations are continuously observing the weather elements hourly. The information is being collated and we carry out an analysis towards the end of the year.
For next year’s rainfall predictions, work has already started gradually, so that we can release it by February next year. In fact, before the end of the year the prediction is almost ready.
Q: Is it possible for what you have predicted earlier to change?
A: That is possible. That is why as we release our prediction, we continue with the monitoring of the weather continuously. And if we find out there will be changes, we alert the public about it.
Q: Can we rest assured that the predictions are completely reliable, even with the equipment that NIMET boasts, considering the fact that the rainfall patterns are somewhat irregular this year?
A: We use a lot of data. But you know weather is dynamic. For instance, here in Lagos, NIMET can give you a forecast that there will be rain in Lagos based on all the information we have had. For instance if I am at home and have not reported to work today and they ask me what the weather will be today, I will say I don’t have an idea until when I get to the office and take a look at all the charts and all the necessary parameters. That is when I can now give you the weather prediction. And even when we have given the prediction, you should realize that Lagos is not just Ikeja, Oshodi or Victoria Island. It encompasses so many towns.
Somebody can be at Yaba and be experiencing rainfall at the time we predicted, while someone in Ikeja will just see only cloudy condition. You may see the clouds gathering or rain building and before you it know it, it clears off. The weather is being controlled by the upper level winds. It can carry the bulk of rain bearing clouds over you to be deposited elsewhere. And if you don’t know the dynamics of weather, you will say ‘these meteorological people are liars’. But now, because of the state-of-the-art equipment we have, our forecast has improved tremendously.
Q: What is your forecast for the rest of the year? Are we to witness more rainfall or not?
A: We have had the first phase of the rains over the South West and we are still expecting to have the second after the break we are now witnessing. By the end of this month, or even before then we will enter the second phase of the rainy season. During this period, we will still have normal rains, but that does not rule out the possibility of flooding. That can still happen.
We know that most of the flooding that occurs is due to the blockage of drainage systems and building on drainage channels. Even with the normal rains expected, if the water cannot find its passage or course, flooding will occur. People should be conscious of this fact.
Q: When will the rains be over this year?
A: Over the South west, we expect the rains to cease between 5 and 28 December that is, between the first week and the last week of December.
In areas up north like Sokoto, Katsina, Dutse, Potiskum, Maiduguri where they are now having heavy rains, the rainy season ends between 27 September and 24 October. This is when the sun starts moving towards the equator, bringing the rains to the South West and the North will begin to witness its dry season.