Manila: Tropical Depression Luis slightly intensified early Sunday as it moved slowly over the Philippine Sea east of Bicol, prompting the weather bureau to maintain Tropical Cyclone Wind Signal (TCWS) No. 1 over parts of Luzon. In its 5 a.m. bulletin, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said the center of Luis was estimated at 295 kilometers east of Daet, Camarines Norte, packing maximum sustained winds of 55 kilometers per hour (kph) near the center, gusts of up to 70 kph, and moving west southwestward slowly. According to Philippines News Agency, TCWS No. 1 remains hoisted over the Polillo Islands, Camarines Norte, the northern portion of Camarines Sur, and Catanduanes, where winds of 39 to 61 kph may pose a minimal to minor threat to life and property. PAGASA warned that the possibility of raising TCWS No. 2 remains possible as the cyclone continues to strengthen. Aside from strong winds, Luis and the southwest monsoon (habagat) are expected to brin g heavy rains and gusty conditions over several parts of the country. Strong to gale-force gusts are forecast Sunday over Marinduque, southern Mindoro, Romblon, mainland Masbate, the Caluya Islands, Siquijor, Southern Leyte, Camiguin, and Dinagat Islands. By Monday and Tuesday, these conditions may extend across most of Luzon and the Visayas, as well as parts of Northern Mindanao, Caraga, and Davao Region. PAGASA said Luis is forecast to intensify into a tropical storm within the next 24 hours while remaining over the Philippine Sea east of Bicol. The weather bureau said the cyclone is expected to move generally westward to west northwestward over the next 36 hours before curving north northeastward. While current forecasts indicate that Luis will remain over water, PAGASA warned that a westward shift in its track could bring it closer to or result in landfall over Northern or Central Luzon. The cyclone is expected to weaken by midweek as it interacts with Super Typhoon Dolphin and may dissipate into a remn ant low by Wednesday. PAGASA advised the public and local disaster risk reduction and management offices to continue monitoring official weather bulletins and take precautionary measures against possible flooding, landslides, strong winds, and rough seas.