Manila: Tropical cyclone Ada (international name Nokaen) has weakened into a tropical depression, the weather bureau said in its 5 a.m. bulletin on Monday. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) reported that Ada now has maximum sustained winds of 55 kilometers per hour (kph) near the center and gustiness of up to 70 kph. The cyclone was last tracked 380 km east of Casiguran, Aurora, moving northeast at 10 kph. According to Philippines News Agency, no tropical cyclone wind signal is hoisted on any part of the country. However, the northeast monsoon or "amihan" and the periphery of Ada will bring strong to gale-force gusts across several regions including Batanes, Cagayan, Isabela, Quirino, Ilocos Norte, Abra, Aurora, Polillo Islands, Camarines Norte, Camarines Sur, Catanduanes, and Northern Samar. Rough seas may prevail over various coastal waters such as the seaboard of Isabela, eastern seaboard of mainland Cagayan, seaboards of Batanes and Babuyan Island s, seaboard of northern Aurora, and several others. Mariners of small seacraft, including all types of motor bancas, are advised not to venture to the sea due to the rough conditions. Meanwhile, PAGASA forecasts that Ada is likely to further weaken and downgrade into a low pressure area by Wednesday.