Following the onset of Harmattan season, the Nigerian Meteorological Agency (NIMET) has warned of disruption in flight schedules due to poor visibility.
The agency explained that during the Harmattan season, sunny and hazy conditions are expected over the Northern states and central cities down to the inland cities of the southern parts with thick dust haze atmosphere that could impair horizontal visibility to less than 1000m (1km).
It noted that the expected reduction in visibility in the coming weeks might disrupt flight operations through cancellation and delay of flights at some airports across the country.
Urging road users to be careful and avoid over speeding especially during early morning period when horizontal visibility is impaired by fog, mist or dust haze, the agency warned that weather conditions could increase traffic congestion or even cause accidents.
In a statement, the Assistant General Manager, Public Relations, Theresa Ushie stressed that the harmattan season is characterised by the prevalence of dry and dusty wind of fine particulate matters emanating from the Sahara desert blowing southward into the country.
It said the severity of the dry season is higher and longer over the North due to its proximity to the Sahara desert compared to the South where rainfall is expected to last till December in some cities.
“Presently, surface pressure is increasing over the Northern Africa and strong surface North easterly wind is gradually building up over the southern Chad and Niger Republic which are the source regions of dust affecting Nigeria. Some states in the northern part of the country are already in hazy conditions with continental wind dominating the region while south westerly wind still prevails over the southern states and some central cities.”
NIMET however noted that cloudy to partly cloudy conditions with scattered thunderstorms are still expected to prevail over the coastal regions till mid-December with occasional dust haze condition.
Occasional early morning fog and mist are also expected over the southern cities.
It added that day time temperatures are anticipated to increase across the country accompanied by decrease night time temperatures resulting in cold nights. Similarly, dryness is anticipated due to expected reduction in humidity and cloud cover.
The statement said surface winds are also expected to be stronger especially over the northern parts, urging people to avoid bush burning as the dryness and strong wind can increase fire incidents and cause severe crop damage at harvesting period.
The agency warned that dust haze contributes to deterioration of air quality and has adverse effects on human health and can trigger asthma and bronchitis attacks as well as cause cold, cough, catarrh, and even meningitis.
It added that those suffering from these health challenges or allergic to dust should take necessary precaution and take their medications to alleviate its effect on their health, urging the public to take adequate water during the harmattan period to avoid dehydration and heatstroke.