Tropical Storm KIYAPO / NOUL
Northern Philippines → Luzon Strait → Northeast South China Sea → Guangdong • 24 July 2026
Meteorological impact dashboard covering surface wind, precipitation, convection, waves, coastal inundation, intensity, storm wake and South China Sea effects.
1. Storm Track & Forecast Timeline
HKO analysed and forecast track
At 05:00 HKT on 24 July , the Hong Kong Observatory analysed NOUL at approximately 17.9°N 124.4°E with maximum sustained winds near the centre of 75 km/h . The HKO track then takes the system into the northeastern South China Sea with further strengthening.
| Date / HKT | Position | Class | Wind |
|---|---|---|---|
| 23 Jul 02:00 | 15.0°N 130.2°E | TD | 45 km/h |
| 23 Jul 08:00 | 15.7°N 129.3°E | TD | 55 km/h |
| 23 Jul 14:00 | 17.1°N 128.3°E | TD | 55 km/h |
| 23 Jul 20:00 | 17.4°N 126.6°E | TD | 55 km/h |
| 24 Jul 02:00 | 17.9°N 125.2°E | TS | 65 km/h |
| 24 Jul 05:00 | 17.9°N 124.4°E | TS | 75 km/h |
| 25 Jul 05:00 | 20.4°N 118.7°E | STS | 110 km/h |
| 26 Jul 05:00 | 23.0°N 115.3°E | TY | 130 km/h |
| 27 Jul 05:00 | 26.4°N 113.9°E | TD | 55 km/h |
| 28 Jul 05:00 | 29.5°N 113.3°E | LPA | 25 km/h |
Northern Hemisphere Cyclone Circulation
Interactive HKT Storm Track
2. Surface Wind Forecast
Northern Luzon / Luzon Strait
Gale-force conditions are possible in exposed parts of extreme northern Luzon, particularly Batanes, Babuyan Islands and northern Cagayan as the cyclone approaches and crosses the region.
- tightening pressure gradient near the cyclone;
- terrain acceleration over islands and headlands;
- stronger gusts within convective rainbands;
- southwest monsoon enhancement behind the system.
Forecast maximum centre wind
Wind impact interpretation
| Region | Main wind concern | Relative risk |
|---|---|---|
| Batanes / Babuyan Islands | Gales, severe squalls and exposed coastal winds | High |
| Northern Cagayan | Strong to gale-force gusts | Moderate–High |
| Luzon Strait | Rapidly deteriorating marine winds | High |
| NE South China Sea | Expanding gale / storm circulation | Increasing |
| Hong Kong vicinity | Dependent on final Guangdong approach | Track-sensitive |
3. Precipitation & Rainband Effects
Expected precipitation structure
KIYAPO/NOUL combines tropical cyclone rainbands with enhanced southwest monsoon moisture transport.
- Core / inner bands: intense short-duration rainfall.
- Outer bands: intermittent heavy squally showers.
- Monsoon wake: continued southwest-flow rainfall behind the cyclone.
Regional rainfall risk
| Area | Rainfall character | Main hazard |
|---|---|---|
| Northern Luzon | Heavy / squally tropical rainbands | Flash flooding / landslides |
| Western Luzon | Enhanced southwest monsoon showers | Repeated rainfall episodes |
| Luzon Strait | Heavy convective bands | Marine visibility / squalls |
| NE South China Sea | Expanding rain shield | Thunderstorms |
| Hong Kong / Guangdong | Track-dependent rainband effects | Heavy squally showers possible |
4. Convection & Thunderstorm Evolution
Moisture
Warm tropical marine air supplies a deep moisture reservoir.
Low-Level Convergence
Spiralling inflow concentrates moisture around rainbands and the cyclone core.
Latent Heat
Condensation releases heat aloft and supports the tropical circulation.
Conceptual Convective Structure
5. Wave & Coastal Inundation Forecast
Northern Philippines Marine Conditions
Very rough seas can develop around the exposed waters of extreme northern Luzon as the cyclone approaches the Luzon Strait.
| Coastal zone | Forecast seas |
|---|---|
| Batanes / Babuyan Islands | Up to 5.5 m |
| Northern mainland Cagayan / Ilocos Norte | Up to 4.5 m |
| Remaining Cagayan / Ilocos Norte waters | Up to 3.0 m |
| Isabela seaboard | Up to 2.5 m |
Extreme-Wave and Inundation Effects
Wave Run-up
An unusually high individual wave can travel farther up an exposed beach, seawall or rocky shore than surrounding waves.
Overtopping
Higher individual waves can increase the chance of seawall, harbour-wall and breakwater overtopping.
Marine Hazard
A steep unexpected wave can impose substantially greater loading on small craft and exposed marine structures.
Coastal Inundation Mechanism
Coastal inundation depends on more than offshore wave height. Actual water penetration can involve the combination of: astronomical tide + storm surge + wave setup + individual-wave run-up .
↑ Back to Top6. Intensity Levels
HKO Forecast Evolution
24 Jul: Tropical Storm
25 Jul: Severe Tropical Storm
26 Jul: Typhoon
27 Jul: Inland weakening
7. Storm Wake
A tropical cyclone may leave substantial oceanic and atmospheric effects behind its centre.
Ocean Mixing
Strong winds stir the upper ocean and can bring cooler subsurface water toward the surface.
Southwest Monsoon
Cyclone circulation may enhance southwesterly moisture transport into western Luzon.
Residual Swell
Long-period swell can remain hazardous after local winds begin to ease.
8. Northeast South China Sea & Hong Kong Effects
Luzon Strait Transition
After crossing the vicinity of extreme northern Luzon, the system is forecast to move into the northeastern South China Sea.
Further organisation over open water can occur before the eventual Guangdong approach.
Hong Kong Sensitivity Factors
- centre-to-Hong Kong distance;
- cyclone circulation size;
- final Guangdong landfall position;
- rainband geometry;
- local tide;
- terrain effects on surface wind.