Tropical Storm Hagupit (05W) – Tropical Cyclone Advisory #3: 1200 UTC 6 May 2026

…Tropical Storm Hagupit passing well to the south of Guam with no change in strength…
…Additional tropical storm warnings and watches issued for Yap State…

Current storm information:

• Position: 7.5°N 145.8°E

• Movement: WSW at 8 knots (15 km/h)

• Intensity: 35 knots (65 km/h)

• Central pressure: 1002 hPa

Trend:

• Little change in strength is forecast during the next 24 hours.

Discussion:

The tropical storm well south of Guam, now named Hagupit by JMA, has a sheared appearance on satellite imagery. This is somewhat unusual considering that CIMSS shear analysis suggests only about 5 to 10 kts of westerly shear affecting the system. Hagupit is not a well organized tropical cyclone, consisting of formless clusters of convection displaced well to the east of the circulation center. The circulation itself is not well defined at all - it is fully exposed and consists of a group of small swirls rotating around a mean center. This is somewhat not surprising as around the time of the previous advisory (where I didn’t write a discussion), Hagupit appeared to be vertically decoupling. There may be stronger shear at the mid-levels but CIMSS data is not currently available. Dvorak estimates from the various agencies are a consensus T2.5, although I am not sure if they are accounting for the circulation center being fully exposed. For the time being, we’ll go with 35 kts since most of the available data supports it.

This is not an easy forecast. Although the track forecast is fairly straightforward due to strong subtropical ridging to the north, the intensity forecast is not. All indications are that the environment should be conducive for some strengthening during the next couple of days. However, given Hagupit’s current structure (or lack thereof), I find it hard to believe that any significant strengthening will occur unless the structure improves. Making things worse for the forecast, a number of ECMWF and GFS ensemble members indicate significant strengthening by the end of the forecast period, by the time a cold front drops into the Philippine Sea and introduces very strong southwesterly shear and drier air into the environment. The deterministic GFS and ECMWF models, as well as the HWRF and HAFS-A models, either dissipate the system outright or reduce it to a remnant low as soon as Sunday. For the time being, the forecast will continue to show little change in strength during the next several days, with Hagupit degenerating into a remnant low in the Philippine Sea at the end of the period. Confidence in this forecast is fairly low at this time.

Forecast positions and maximum winds (1-min)

• 000 hrs: 07.5°N 145.8°E – 35 kts 65 km/h

• 012 hrs: 07.8°N 143.5°E – 35 kts 65 km/h

• 024 hrs: 08.2°N 141.8°E – 35 kts 65 km/h

• 048 hrs: 09.4°N 138.3°E – 35 kts 65 km/h

• 072 hrs: 10.4°N 135.3°E – 30 kts 55 km/h

• 096 hrs: 11.6°N 132.6°E – 30 kts 55 km/h

• 120 hrs: 12.8°N 130.4°E – 25 kts 45 km/h POST-TROPICAL/REMNANT LOW