NiMet warns airlines, travellers of imminent harmattan haze in the north

The Nigerian Meteorological Agency (NiMet) has warned airlines and the travelling public of imminent harmattan dust haze that will disrupt horizontal visibility values in the northern region of the country.

A weather update issued by the agency indicates that the imminent haze is expected to be raised “at Faya Largeau in the Chad Republic, a major dust source region for Nigeria & West Africa.”

One of the expected effects of the haze on the atmosphere, according to the agency, is that “the Saharan high-pressure cell and its pressure belt across the Saharan deserts with centre value at 1021hPa on 17^th is expected to intensify further to about 1025hPa on 18^th and 1027hPa on both 19^th & 20^th.”

“Other possible effects include “the tightening of its (Saharan) pressure gradient is expected to be strengthened on 18th and on 19th; stronger surface (10m) winds at the dust source (Saharan) regions is expected; and a strong upper-air wind speed of about 40 – 45 knots, at the dust transport (925hPa) level, with a direction that favours dust dispersion from this source region to the northern parts of Nigeria.

“Two major dust plumes are expected to be successively raised at Faya Lareau in the Chad Republic on the 18^th and 19^th, the dust is expected to progressively reduce the horizontal visibility values in the extreme northern parts of Nigeria from the 19^th to less than 5000m.

“Significant visibility deterioration is expected on the 20^th in some northern cities such as Maiduguri, Kano, Katsina, and Sokoto with visibility values ranging from 5000-2000 m with isolated cases of visibility below 1000.

“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.

“Motorists are advised to drive with caution especially in the extreme northern parts where reduction in visibility is envisaged. More attention is expected especially during the early morning period when horizontal visibility is mostly impaired.

“Hot and dry atmospheric conditions associated with harmattan could result in heat exhaustion and dehydration, hence keeping the body hydrated by drinking water is crucial to avoid heatstroke.

“However, temperatures at night could be very low, adequate clothing is therefore essential. The expected reduction in visibility may disrupt flight operations through cancellation and delay of flights; this is for the safety of air travelers.