Monthly Archives: May 2026

Tropical Storm Hagupit Passes South of Guam

Tropical Storm Hagupit passed well to the south of Guam on Wednesday night.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Hagupit was located at latitude 7.2°N and longitude 142.5°E which put the center about 355 miles (575 km) east-southeast of Yap.  Hagupit was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1001 mb.

Tropical Storm Hagupit exhibited a little more organization on Thursday morning.  Thunderstorms were once again forming in bands in all parts of Hagupit’s circulation.  Thunderstorms near the center of Hagupit generated more upper level divergence that pumped mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease slightly.

Even though Tropical Storm Hagupit looked more organized on satellite images, the distribution of wind speeds continued to be asymmetrical.  Winds to tropical storm force extended out 115 miles (185 km) in the northern side of Hagupit’s circulation.  The winds in the southern half of Tropical Storm Hagupit were blowing at less that tropical storm force.

Tropical Storm Hagupit will move through an environment favorable for intensification during the next 24 hours.  Hagupit will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Hagupit’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Hagupit will intensify slowly during the next 24 hours.

Tropical Storm Hagupit will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Hagupit toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Hagupit will approach Yap in 24 hours.

Tropical storm Hagupit will bring strong winds and locally heavy rain to Yap.  Heavy rain could cause flash floods in some locations.

Depression Strengthens to Tropical Storm Hagupit

Former Tropical Depression 05W strengthened to Tropical Storm Hagupit over the Western North Pacific Ocean south of the Marianas on Tuesday night.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Hagupit was located at latitude 7.4°N and longitude 146.5°E which put the center about 435 miles (705 km) south-southeast of Guam.  Hagupit was moving toward the west at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1003 mb.

Former Tropical Depression 05W strengthened on Tuesday night and the Japan Meteorological Agency designated the system as Tropical Storm Hagupit.

Thunderstorms continued to develop near the center of Tropical Storm Hagupit.  However, the distribution of thunderstorms around the rest of Hagupit’s circulation became a little more asymmetrical during the past 12 hours.  Thunderstorms were still occurring in bands in the eastern side of Tropical Storm Hagupit.  Bands in the western side of Hagupit’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Hagupit generated some upper level divergence that pumped mass away from the tropical storm.  The removal of mass in the upper levels was nearly matched by the inflow of mass in the lower levels of the atmosphere.  So, the surface pressure was not changing much.

The distribution of wind speeds in Tropical Storm Hagupit was also asymmetrical.  Winds to tropical storm force extended out 100 miles (160 km) in the northeastern quadrant of Hagupit’s circulation.  The winds in the other parts of Tropical Storm Hagupit were blowing at less than tropical storm force.

Tropical Storm Hagupit will move through an environment favorable for intensification during the next 24 hours.  Hagupit will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Hagupit’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Hagupit will intensify slowly during the next 24 hours.  Hagupit could strengthen to a typhoon later this week.

Tropical Storm Hagupit will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Hagupit toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Hagupit will pass south of Guam.  Hagupit could approach Yap in 48 hours.  Hagupit will likely be a tropical storm when it approaches Yap.

Tropical Depression 05W Forms Southeast of the Marianas

Tropical Depression 05W formed over the Western North Pacific Ocean southeast of the Marianas on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Depression 05W was located at latitude 8.4°N and longitude 147.8°E which put the center about 100 miles (160 km) north-northwest of Puluwat.  Tropical Depression 05W was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1003 mb.

A low pressure system over the Western North Pacific Ocean southeast of the Marianas strengthened on Tuesday.  Both the Japan Meteorological Agency and the U.S. Joint Typhoon Warning Center designated the system as a tropical depression.

More thunderstorms formed near the center of Tropical Depression 05W on Tuesday afternoon.  More thunderstorms also developed in bands revolving around the center of the tropical depression.  Storms near the center of circulation started to generate upper level divergence that pumped mass away from the tropical depression.  The removal of mass caused the surface pressure to decrease.

Tropical Depression 05W will move through an environment favorable for intensification during the next 24 hours.  The tropical depression will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of the tropical depression.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Depression 05W will intensify to a tropical storm during the next 24 hours.  It could strengthen to a typhoon later this week.

Tropical Depression 05W will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer the tropical depression toward the west during the next 24 hours.  On its anticipated track, Tropical Depression 05W will pass south of Guam.  The tropical depression could approach Yap in 36 hours.  It will likely be a tropical storm when it approaches Yap.