The Nigeria Meteorological Agency (NIMET) has warned pilots and airlines that starting from November 18, the inclement Harmattan weather could descend on Nigeria’s airspace, advising them to abide by weather updates from the agency.
In a circular signed by the Director General of NIMET, Prof. Mansur Matazu, the agency also warned air travellers to recognise that flights could be delayed or cancelled due to unfavorable weather.
NIMET said dust, which is spreading from Faya Largeau in Chad Republic, a major dust source region for Nigeria and West Africa, would intensify in the coming days.
“The Saharan high-pressure cell and its pressure belt across the Saharan deserts with centre value at 1,021hPa on November 17th is expected to intensify further to about 1025hPa on 18th and 1027hPa on both 19th and 20th,” the circular said.
Identifying the effect of the unfavourable weather, NIMET said such weather is indicated by the tightening of its (Saharan) pressure gradient, which is expected to be strengthened on November 18 and on 19.
It would also come with stronger surface (10m) winds at the dust source (Saharan) regions, gathering momentum with strong upper-air wind speed of about 40 – 45 knots, at the dust transport (925hPa) level, with direction that favours dust dispersion from this source region to the northern parts of the Nigeria.
“Two major dust plumes are expected to be successively raised at Fayal Largeau in Chad Republic on the November 18th and 19th, the dust is expected to progressively reduce the horizontal visibility values in the extreme northern parts of Nigeria from the 19th to less than 5000m.
“Significant visibility deterioration is expected on the 20th in some northern cities such as Maiduguri, Kano, Katsina and Sokoto with visibility values range from 5000-2000 meters with isolated cases of visibility below 1000 meters. Most parts of the central states are expected to be partly cloudy with sunny intervals while the southern states are expected to be cloudy with prospects of isolated thunderstorms,” the circular said.
NIMET also advised motorists to drive with caution especially in the extreme northern parts where reduction in visibility is envisaged, adding that more attention is expected especially during the early morning period when horizontal visibility is mostly impaired.
“Hot and dry atmospheric condition associated with harmattan could result in heat exhaustion and dehydration, hence keeping the body hydrated by drinking water is crucial to avoid heat stroke, however temperatures at night could be very low, adequate clothing is therefore essential.