Two dangerous tropical cyclones are plying the South Pacific Ocean.Tropical Cyclone Ului is the more powerful of the two.

As of late Saturday morning, EST, Ului wielded sustained winds as high as120 mph around its eye; gusts were as high as 150 mph. These wind speeds gavethe storm a Category-3 ranking on the Saffir-Simpson Scale. Centered 305 milesto the southeast of Honiara, Guadalcanal, Solomon Islands, Ului was driftingtoward the west-northwest at 8 mph.

Ului is forecast to strengthen significantly, attaining Category-5 strengthSaturday night or Sunday. With the cyclone's projected path generally headingto the west, its violent core would pass largely to the south of the SolomonIslands during upcoming days. However, the nation's southern islands, includingGuadalcanal and San Cristobal, would be lashed by high winds and heavy rain.

Rennell Island, in particular, could be dealt a severe blow.

Meanwhile, Tropical Cyclone Tomas looms as a serious threat to Fiji.

As of late Saturday morning, EST, Tomas held maximum sustained winds of 75mph and gusts to 90 mph around its center which was about 420 miles to thenorth-northeast of Suva, Viti Levu, Fiji; it was drifting southwestward at 7mph.

Tomas is forecast to strengthen while taking on a southward heading. On itsprojected course, the cyclone would deliver a direct hit upon the island ofVanua Levu and also hammer Viti Levu early next week. The storm has thepotential to unleash destructive winds and flooding rain upon Fiji.

Story by AccuWeather.com Senior Meteorologist Donn Washburn