22/08/2025
TROPICAL CYCLONE BULLETIN NR. 1
Tropical Depression
Issued at 11:00 AM, 22 August 2025
Valid for broadcast until the next bulletin at 2:00 PM today.
THE LOW PRESSURE AREA EAST OF AURORA HAS DEVELOPED INTO TROPICAL DEPRESSION ISANG AND MADE LANDFALL OVER CASIGURAN, AURORA
โข Location of Center (10:00 AM)
The center of Tropical Depression ISANG was estimated based on all available data in the vicinity of Casiguran, Aurora (16.3ยฐN, 122.1ยฐE).
โข Intensity
Maximum sustained winds of 55 km/h near the center, gustiness of up to 90 km/h, and central pressure of 1002 hPa
โข Present Movement
Westward at 15 km/h
โข Extent of Tropical Cyclone Winds
Strong winds extend outwards up to 200 km from the center
TROPICAL CYCLONE WIND SIGNALS (TCWS) IN EFFECT
TCWS No.1
(Wind threat: Strong winds)
Warning lead time: 36 hours
Range of wind speeds: 39 to 61 km/h (Beaufort 6 to 7)
Potential impacts of winds: Minimal to minor threat to life and property
Luzon:
Batanes, Cagayan, Isabela, Quirino, Nueva Vizcaya, Apayao, Kalinga, Abra, Mountain Province, Ifugao, Benguet, Ilocos Norte, Ilocos Sur, La Union, Pangasinan, the northern and central portions of Aurora (Casiguran, Dinalungan, Dilasag, Baler, Maria Aurora, Dipaculao, San Luis) and the northern portion of Nueva Ecija (Lupao, Carranglan, Pantabangan, San Jose City)
OTHER HAZARDS AFFECTING LAND AREAS
Heavy Rainfall Outlook
Refer to Weather Advisory issued No. 4 at 11:00 AM today for the heavy rainfall outlook due to Tropical Depression ISANG and the Southwest Monsoon.
Severe Winds
The wind signals warn the public of the general wind threat over an area due to the tropical cyclone. Local winds may be slightly stronger/enhanced in coastal and upland/mountainous areas exposed to winds. Winds are less strong in areas sheltered from the prevailing wind direction.
โข Minimal to minor impacts from strong winds are also possible within any of the areas under Wind Signal No. 1.
The Southwest Monsoon slightly enhanced by ISANG will bring strong to gale-force gusts over the following areas (especially in coastal and upland areas exposed to winds):
โข Today: Aurora (areas not under Wind Signal) Zambales, Bataan, Metro Manila, CALABARZON, MIMAROPA, Camarines Norte, Camarines Sur, Catanduanes, Burias Island, Western Visayas, Negros Island Region, Central Visayasa, Dinagat Islands, Southern Leyte, Surigao del Norte, and Camiguin.
โข Tomorrow (23 August): Batanes, Cagayan, Ilocos Region, Cordillera Administrative Region, Zambales, Bataan, Tarlac, Pampanga, Bulacan, Metro Manila, Cavite, Rizal, Palawan, Occidental Mindoro, Romblon, Burias Island, Camarines Sur.
โข Sunday (24 August): Kalayaan Islands.
HAZARDS AFFECTING COASTAL WATERS
24-Hour Sea Condition Outlook
No Gale Warning hoisted at this time.
Up to rough seas over the following coastal waters:
โข Up to 3.0 m: The seaboards of Batanes and Cagayan.
โข Mariners of small seacrafts, including all types of motorbancas, are advised not to venture out to sea under these conditions, especially if inexperienced or operating ill-equipped vessels.
Up to moderate seas over the following coastal waters:
โข Up to 2.5 m: The seaboards of Isabela, Ilocos Norte, and Ilocos Sur.
โข Up to 2.0 m: The seaboard of Aurora and Zambales; the western seaboards of Bataan and Lubang Island.
โข Mariners of motorbancas and similarly-sized vessels are advised to take precautionary measures while venturing out to sea and, if possible, avoid navigation under these conditions.
TRACK AND INTENSITY OUTLOOK
โข Tropical Depression ISANG will move generally westward during the forecast period. On the track forecast, it will traverse Northern Luzon in the next 12 hours, emerge over the West Philippine Sea tonight, and eventually exit the Philippine Area of Responsibility tomorrow (23 August) morning or afternoon.
โข ISANG is forecast to intensify into a tropical storm tomorrow morning and may reach severe tropical storm category while approach the waters south of Hainan, China. However, intensification into a tropical storm at a much earlier time (e.g., several hours after emerging over the West Philippine Sea) is not ruled out.
Considering these developments, the public and disaster risk reduction and management offices concerned are advised to take all necessary measures to protect life and property. Persons living in areas identified to be highly or very highly susceptible to these hazards are advised to follow evacuation and other instructions from local officials. For heavy rainfall warnings, thunderstorm/rainfall advisories, and other severe weather information specific to your area, please monitor products issued by your local PAGASA Regional Services Division.
The next tropical cyclone bulletin will be issued at 2:00 PM today.
DOST-PAGASA
