Typhoon Sinlaku (04W) – Tropical Cyclone Advisory #17: 1200 UTC 16 April 2026

Sinlaku finally moving away from the populated Northern Mariana Islands after relentlessly lashing Tinian and Saipan for over two days.

Author

Will Weaver
April 16, 2026

…Sinlaku finally moving away from the populated Northern Mariana Islands after relentlessly lashing Tinian and Saipan for over two days…

Himawari-9 infrared satellite image (Weathernerds)

Current storm information:

  • Position: 18.4°N 144.8°E

  • Movement: NNE at 6 knots (10 km/h)

  • Intensity: 90 knots (165 km/h)

  • Intensity category: 2

  • Central pressure: 958 hPa

Trend:

  • Gradual weakening is forecast during the next 24 hours.

Watches and warnings:

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

Areas that should monitor this system:

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

Hazards affecting land:

  • Conditions on Rota, Tinian, and Saipan should finally begin to improve during the next several hours. However, tropical storm force winds are still occurring on those islands and it is still not safe to venture outdoors. Remain in your safe place until an all-clear is given.

  • 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:

METOP-B 89GHz microwave satellite image (RAMMB/CIRA)

Sinlaku is finally, finally beginning to pull away from the populated Northern Mariana Islands, and the typhoon’s satellite presentation has degraded significantly during the past several hours. Convective cloud tops within the CDO have warmed quite a bit, and much of the convection north and northwest of the eye has completely eroded away as the extremely dry air mass located over the Philippine Sea has finally infiltrated the circulation. The eye itself has shrunk and become ragged, and microwave satellite imagery indicates the eyewall has begun eroding away, although convection within it has tried to rebound slightly in the past couple of hours. This appears to be a product of both an ongoing eyewall replacement cycle and steadily decreasing oceanic heat content and SSTs. Estimates of Sinlaku’s intensity are dropping as quickly as the Dvorak technique’s constraints allow, and the current intensity is lowered to 90 kts, hedged between T5.0 Dvorak fixes from PGTW and KNES, and automated CIMSS estimates averaging out to about 91 kts.

Sinlaku is still embedded in weak steering currents, but it is being steered slowly toward the north-northeast due to the influences of a weak ridge to the east and a deep-layer trough to the north. This slow movement is unfortunately expected to continue for the next couple of days as the trough is expected to leave Sinlaku behind by Saturday as it moves over the northernmost Mariana Islands. Sinlaku won’t be parked for very long as another developing frontal system near the Kuril Islands should arrive to sweep Sinlaku east-northeastward and out to sea. SSTs are forecast to steadily decrease along Sinlaku’s track, and a steady weakening trend is forecast through Sunday, when baroclinic forcing from the frontal system should cause Sinlaku to undergo extratropical transition and become a strong storm-force post-tropical cyclone as it approaches the International Date Line next week.

Forecast positions and maximum winds (1-min)

  • 000 hrs: 18.4°N 144.8°E – 90 kts 165 km/h 

  • 012 hrs: 19.4°N 145.2°E – 80 kts 150 km/h 

  • 024 hrs: 21.2°N 146.0°E – 70 kts 130 km/h 

  • 048 hrs: 24.5°N 147.9°E – 60 kts 110 km/h 

  • 072 hrs: 28.3°N 153.1°E – 55 kts 100 km/h POST-TROPICAL/EXTRATROPICAL

  • 096 hrs: 31.9°N 165.9°E – 55 kts 100 km/h POST-TROPICAL/EXTRATROPICAL

  • 120 hrs: 37.4°N 179.6°E – 50 kts 95 km/h POST-TROPICAL/EXTRATROPICAL

Forecast map (click to enlarge)