Super Typhoon Sinlaku (04W) – Tropical Cyclone Advisory #11: 1200 UTC 13 April 2026

Outer bands of Category 5 Sinlaku moving over Guam and the CNMI. Forecast to pass between Tinian and Saipan at or near Category 5 strength late Tuesday night. This is a particularly dangerous situation!

Author

Will Weaver
April 13, 2026

…Outer bands of potentially catastrophic Category 5 Sinlaku moving over Guam, Rota, Tinian, and Saipan…
…Forecast to pass between Tinian and Saipan at or near Category 5 strength late Tuesday night…
…This is a particularly dangerous situation…

Himawari-9 infrared satellite image (Weathernerds)

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Current storm information:

  • Position: 13.1°N 147.4°E

  • Movement: WNW at 7 knots (10 km/h)

  • Intensity: 150 knots (280 km/h)

  • Intensity category: 5

  • Central pressure: 903 hPa

Trend:

  • A slow weakening trend is expected during the next 24 hours. However, Sinlaku is expected to remain a potentially catastrophic Category 5 typhoon during that time as it approaches Tinian and Saipan.

Watches and warnings:

  • Typhoon warning (NWS) - Rota, Tinian, and Saipan in the CNMI

  • Tropical storm warning (NWS) - Guam; Pagan and Alamagan in the CNMI

  • Tropical storm watch (NWS) - Agrihan in the CNMI

  • TCCOR 1 - Guam

Areas that should monitor this system:

  • Guam

  • Rota, Tinian, Saipan, Pagan, Alamagan, and Agrihan in the CNMI

Hazards affecting land:

  • Sinlaku is forecast to make a very close approach to Tinian and Saipan on Tuesday. Although Sinlaku is forecast to be at a slightly lower intensity by then, it is expected to remain at or near Category 5 intensity. Potentially catastrophic damaging winds and heavy rain are expected to begin late Monday night and could persist through Wednesday. This is an extremely dangerous and life-threatening situation! Preparations to protect life and property should have been completed by now. Refer to products from your local weather office for further information.

  • Information for U.S. military interests can be found at the Stars & Stripes Pacific Storm Tracker, located here: https://www.stripes.com/theaters/asia_pacific/storm_tracker/

Discussion:

NWS Guam radar image of Sinlaku (CyclonicWx)

Sinlaku teased us all with the concentric eyewall structure it had developed prior to the previous advisory, because it has not undergone an eyewall replacement cycle. Now that Sinlaku’s core is within range of Guam radar, radar and microwave satellite imagery indicate that the concentric eyewall structure that was present is now mostly gone, with just a small moat of dry air located in the northwestern quadrant of the eyewall. The eye itself is unchanged and still quite warm at 21-22°C compared to -85°C cloud tops within the central dense overcast. Convection in the northern semicircle has started to erode somewhat, likely due to ever so slightly cooler SSTs underneath that portion of the cyclone. Sinlaku continues to sport excellent radial outflow that is fighting off a pool of extremely dry air over the Philippine Sea while being vented by a deepening trough to the north. Dvorak estimates range from T7.0 to T7.5 from the various agencies and CIMSS ADT, D-PRINT, D-MINT, and SATCON estimates range from 147 to 156 kts; taking a blend of this data supports an intensity of 150 kts.

Closeup of the JMA forecast track showing a track directly between Tinian and Saipan

The forecast track has been nudged very slightly to the north of the previous one based on model trends. On this track, the center of Sinlaku is now forecast to pass between Tinian and Saipan tomorrow night, which is more or less a worst-case scenario for those islands. Given the large size of Sinlaku’s wind field, tropical storm conditions will likely begin on Guam, Rota, Tinian, and Saipan well before then, probably within the next couple of hours or so. As dry air manages to work its way into the circulation and SSTs gradually decrease along the forecast track, Sinlaku is forecast to weaken very gradually and it will likely still be at or near Category 5 intensity as it makes its closest approach to the CNMI. 

By Wednesday evening, Sinlaku should turn northward and parallel the northernmost Northern Mariana Islands. The weakening trend should accelerate as it moves over 26-27°C SSTs and southwesterly shear increases ahead of the aforementioned trough to the northwest. Sinlaku should turn north-northeastward well north of the Marianas by Saturday, and interaction with the trough and much stronger shear should result in the system becoming a powerful post-tropical cyclone just after the end of the forecast period.

Forecast positions and maximum winds (1-min)

  • 000 hrs: 13.1°N 147.4°E – 150 kts 280 km/h 

  • 012 hrs: 14.0°N 146.4°E – 145 kts 270 km/h 

  • 024 hrs: 15.2°N 145.6°E – 140 kts 260 km/h 

  • 048 hrs: 16.8°N 144.3°E – 120 kts 220 km/h 

  • 072 hrs: 19.3°N 143.9°E – 105 kts 195 km/h 

  • 096 hrs: 21.7°N 144.6°E – 80 kts 150 km/h 

  • 120 hrs: 25.2°N 146.2°E – 70 kts 130 km/h

Forecast map