The Southwest Monsoon — known locally as the habagat — intensified its presence over the western side of Northern Luzon on Thursday, June 11, 2026, raising significant concerns about flash floods and landslides in several northern provinces. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) placed Ilocos Norte, Batanes, and the Babuyan Islands under heightened weather alerts, while the rest of the archipelago braces for scattered thunderstorms driven by localized weather systems.
PAGASA Issues 24-Hour Forecast Bulletin
PAGASA released its official 24-hour public weather forecast at 4:00 AM on Thursday, June 11, 2026, with the bulletin remaining valid through 4:00 AM on Friday, June 12. The forecast covers wind patterns, coastal water conditions, temperature data, and localized hazard risks across the entire country.
According to PAGASA, the most significant weather driver on Thursday is the Southwest Monsoon, a seasonal wind system that typically reaches peak intensity between June and September. This year, the habagat is channeling warm, moisture-heavy air from the West Philippine Sea directly into the northern tip of Luzon, creating conditions ripe for heavy rainfall accumulation and associated ground hazards.
Luzon: Northern Provinces Bear the Brunt
Ilocos Norte, Batanes, and the Babuyan Islands
Communities in Ilocos Norte, the island province of Batanes, and the Babuyan Islands face the most severe weather exposure on Thursday. PAGASA forecasts cloudy skies accompanied by scattered rains and thunderstorms across these areas — a direct consequence of the monsoon's grip on the western section of Northern Luzon.
The weather agency specifically flagged flash floods and landslides as the primary hazards for these provinces. Moderate to occasionally heavy rainfall can accumulate rapidly, threatening low-lying neighborhoods near river channels as well as communities built along hillside and mountainous terrain. Residents in these vulnerable zones are urged to stay alert and comply with any evacuation orders from their respective local government units.
Sea conditions off Northern Luzon have also deteriorated. PAGASA reports south to southwest winds generating wave heights of 1.2 to 2.5 meters in coastal waters — conditions classified as rough and dangerous for small watercraft. Fisherfolk and operators of bancas and small fishing vessels are strongly advised to defer sea voyages until conditions improve.
Metro Manila and Other Luzon Provinces
Outside the direct monsoon path, Metro Manila and the remaining Luzon provinces can expect partly cloudy to cloudy skies with isolated rain showers or thunderstorms on Thursday. PAGASA attributes these weather disturbances to localized thunderstorm activity rather than the monsoon system itself.
Although conditions are considerably milder compared to the far north, PAGASA cautions that flash floods and landslides can still occur during intense, short-duration downpours. Metro Manila's notoriously low-lying barangays and congested drainage systems are especially vulnerable to rapid urban flooding even from brief but heavy rain events. Residents should avoid flood-prone streets and clogged waterways during rainfall.
Winds across this area blow from the southeast to south at light to moderate speeds, with coastal waters showing slight to moderate swells of 0.6 to 1.5 meters in wave height.
Visayas: Isolated Thunderstorms on Watch
Across the Visayas — covering Eastern, Western, and Central Visayas — the forecast mirrors the general nationwide outlook outside the monsoon zone. Partly cloudy to cloudy skies with isolated rain showers or thunderstorms are expected throughout the day, all linked to localized convective activity rather than any organized weather system.
PAGASA advises that even isolated thunderstorms carry the potential to trigger flash floods and landslides, particularly in upland and coastal communities. Residents in mountainous zones — including those in the Negros highlands, Samar, and Leyte — should remain on alert for sudden weather deterioration. Winds and seas across the Visayas are light to moderate from the southeast to south, with wave heights ranging from 0.6 to 1.5 meters.
Mindanao: General Caution Remains
Mindanao falls under the same nationwide general forecast: partly cloudy to cloudy conditions with isolated rain showers or thunderstorms powered by localized weather systems. The same flash flood and landslide cautions are in effect for periods of severe thunderstorm activity.
The island's diverse landscape — from the highland plateaus of Bukidnon and the mountain ranges of the Davao region to the expansive low-lying coastal plains of Cotabato and Lanao — makes it inherently susceptible to localized flooding. PAGASA emphasizes that even isolated thunderstorm episodes should not be dismissed lightly. Coastal and wind conditions around Mindanao are similar to the rest of the country, with light to moderate southeast to south winds and seas at 0.6 to 1.5 meters.
Temperature Data from Science Garden
The latest temperature readings from PAGASA's official weather station at Science Garden in Diliman, Quezon City — covering the 24-hour period ending 8:00 PM on Wednesday, June 10 — recorded a peak temperature of 34.3°C at 1:00 PM and a low of 27.4°C at 5:00 AM. Relative humidity over the same period swung between a high of 89 percent and a low of 49 percent.
These figures are consistent with typical early-June Metro Manila weather: hot and humid afternoons giving way to warm, uncomfortable nights. PAGASA and health authorities advise children, senior citizens, and outdoor workers to stay well-hydrated and reduce prolonged exposure to direct sunlight during peak afternoon hours.
Tidal Schedules and Astronomical Data for Metro Manila
For Thursday, June 11, PAGASA and the National Mapping and Resource Information Authority (NAMRIA) provide the following tidal predictions for Manila Bay: a high tide of 0.87 meters at 6:46 AM, a low tide of 0.34 meters at 1:41 PM, a second high tide of 0.54 meters at 7:12 PM, and a final low tide of 0.39 meters at 11:45 PM.
Metro Manila's sunrise is at 5:26 AM with sunset at 6:25 PM. The moon rises at 1:33 AM and sets at 2:24 PM, with a slim 19 percent illumination — a thin crescent phase that will offer very little natural light after dark.
Safety Advisories and Precautions
PAGASA's bulletin carries explicit hazard warnings for flash floods and landslides in Northern Luzon, alongside a general nationwide caution for the same risks should severe thunderstorms develop. The weather agency urges the public to take the following safety measures seriously.
In Ilocos Norte, Batanes, and the Babuyan Islands, residents should avoid crossing swollen rivers or streams, steer clear of slopes prone to landslides during prolonged rain, and never seek shelter under trees during active lightning. Community members should monitor announcements from local disaster risk reduction and management offices and be ready to evacuate at short notice.
For Metro Manila and all other regions, PAGASA warns that sudden, intense downpours can trigger localized flooding even without a formal weather warning in place. The public is encouraged to keep emergency contact numbers accessible, avoid unnecessary outdoor activities during heavy rain, and stay updated through official PAGASA channels and local government broadcasts.
Mariners navigating Northern Luzon waters should treat the current sea conditions — with wave heights reaching up to 2.5 meters — with serious caution. According to PAGASA, small vessels should postpone trips until the monsoon's influence weakens and seas return to safer levels.
Originally reported by: breakingnewsnegor.com / wire reports