The mercury is likely to fall substantially today across all the emirates with the rapid onset of the strong Shamal (north-western) winds. Conditions will be hazy and partly cloudy to cloudy at times over northern areas, with a chance of light rain in the morning, according to the National Centre of Meteorology and Seismology (NCMS). The winds will be moderately rough but will later gain speed. They will be very strong over the sea and could kick up dust and sand in open areas and the western region, affecting horizontal visibility. Fall in temperature \"There will be a significant fall in temperature, especially in coastal and western areas,\" the NCMS forecast said. The maximum temperature is expected to be 21 degree Celsius. The forecast said the country witnessed a remarkable increase of five to seven degree Celsius in temperature on Wednesday under the influence of hot south-easterly winds. The maximum temperature recorded was 30.1 degrees Celsius at some places on Wednesday. South-easterly winds also spread a layer of fine dust over all the emirates yesterday. Directive to motorists The centre has warned motorists to be careful on highways due to low visibility and choppy conditions. The NCMS has also advised people to stay away from the sea during the weekend as the stormy waters could pose a threat to their safety. The sea is not fit for small boats and fishing trawlers, a forecaster said. The sea will be very rough with eight to 12-feet-high waves offshore. An atmospheric high pressure has extended from over Saudi Arabia to the UAE yesterday, accelerating north-westerly winds to become stronger over the sea. These winds would extend to the western areas and other parts of the country. The clouds will gradually accumulate over the UAE islands in the Arabian Gulf and the northern areas.