Guam Environment & Hazard Risk

On May 17th a circulation that had been over the area for a few days was classified as Invest 97W by JTWC. 97W was located to the west-southwest of Chuuk at that time. Scatterometer data showed a west-wind burst south of the circulation with winds up to 30 knots. On the morning of May 18th, 97W was located near 6N147E. At this time strong convection was located to the southeast of the center with cloud-top temperatures down to -83C. These temperatures correspond to cloud tops up to 56k feet. The circulation continued to organize over the next few days. Scatterometer satellite imagery shows a well-defined circulation center surrounded by 20 to 25-knot winds by the 20th of May. ||On the afternoon of May 20th, the circulation was classified as Tropical Depression 02W. The tropical depression was located near 5.6N 149.0E or about 235 miles west-southwest of Chuuk with maximum sustained winds of 30 mph. 02W continued to intensify and by the morning of the 21st of May it became Tropical Storm Mawar. Mawar was located near 5.9N 149.2E at about 185 miles west-southwest of Chuuk.|Winds were up to 40 mph. Mawar continues to intensify and by the morning of the 22nd of May, it became a...

A tropical disturbance was noted just northwest of Kosrae on the morning of October 21 near 8N160E. By the morning of October 22 the system had become Tropical depression 31W and was 130 miles north-northwest of Pohnpei. 31W continued to intensify through the day and by the afternoon of the 22nd became Tropical Storm Yutu. Yutu continued to strengthen and became a typhoon on the afternoon of October |23rd. ||Yutu continued to intensify and on the afternoon of the 24th it became a Super Typhoon. A Super Typhoon is a Joint Typhoon Warning Center's designation placed on a system if wind speeds in the typhoon equal or exceed 150 mph. At that time Yutu was less than 200 miles to the east of the Marianas.||The 20 mile wide eye of Super Typhoon Yutu crossed over Tinian between midnight and 0400 ChST||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| on October 25th. Saipan is not too far away from Tinian and the southern part of the island had the destructive eye wall pass over it. The highest wind gust recorded on Saipan was 90 knots (104 mph) at 24/1444Z. Weather instruments on Tinian and Saipan were either destroyed or damaged and this was most...

A tropical disturbance was noted just northwest of Kosrae on the morning of October 21 near 8N160E. By the morning of October 22 the system had become Tropical depression 31W and was 130 miles north-northwest of Pohnpei. 31W continued to intensify through the day and by the afternoon of the 22nd became Tropical Storm Yutu. Yutu continued to strengthen and became a typhoon on the afternoon of October |23rd. ||Yutu continued to intensify and on the afternoon of the 24th it became a Super Typhoon. A Super Typhoon is a Joint Typhoon Warning Center's designation placed on a system if wind speeds in the typhoon equal or exceed 150 mph. At that time, Yutu was less than 200 miles to the east of the Marianas.||The 20 mile wide eye of Super Typhoon Yutu crossed over Tinian between midnight and 0400 ChST on October 25th. Saipan is not too far away from Tinian and the southern part of the island had the destructive eye wall pass over it. The highest wind gust recorded on Saipan was 90 knots (104 mph) at 24/1444Z. Weather instruments on Tinian and Saipan were either destroyed or damaged and this was most likely not the highest winds that occurred. Ground based storm assessment estimated...

A tropical disturbance was noted just northwest of Kosrae on the morning of October 21 near 8N160E. By the morning of October 22 the system had become Tropical depression 31W and was 130 miles north-northwest of Pohnpei. 31W continued to intensify through the day and by the afternoon of the 22nd became Tropical Storm Yutu. Yutu continued to strengthen and became a typhoon on the afternoon of October |23rd. ||Yutu continued to intensify and on the afternoon of the 24th it became a Super Typhoon. A Super Typhoon is a Joint Typhoon Warning Center's designation placed on a system if wind speeds in the typhoon equal or exceed 150 mph. At that time Yutu was less than 200 miles to the east of the Marianas.||The 20 mile wide eye of Super Typhoon Yutu crossed over Tinian between midnight and 0400 ChST||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| on October 25th. Saipan is not too far away from Tinian and the southern part of the island had the destructive eye wall pass over it. The highest wind gust recorded on Saipan was 90 knots (104 mph) at 24/1444Z. Weather instruments on Tinian and Saipan were either destroyed or damaged and this was most...

A tropical disturbance was noted just northwest of Kosrae on the morning of October 21 near 8N160E. By the morning of October 22 the system had become Tropical depression 31W and was 130 miles north-northwest of Pohnpei. 31W continued to intensify through the day and by the afternoon of the 22nd became Tropical Storm Yutu. Yutu continued to strengthen and became a typhoon on the afternoon of October |23rd. ||Yutu continued to intensify and on the afternoon of the 24th it became a Super Typhoon. A Super Typhoon is a Joint Typhoon Warning Center's designation placed on a system in the Western North Pacific if wind speeds in the typhoon equal or exceed 150 mph. At that time Yutu was less than 200 miles to the east of the Marianas.||The 20 mile wide eye of Super Typhoon Yutu crossed over Tinian between midnight and 4 a.m. on October 25th. Saipan is not too far away from Tinian and the southern part of the island had the destructive eye wall pass over it. The highest wind gust recorded on Saipan was 90 knots (104 mph) at 24/1444Z. Weather instruments on Tinian and Saipan were either destroyed or damaged and this was most likely not the highest winds that occurred. Ground based...

Super Typhoon Sinlaku passed north of Guam and Rota and passed near or over Tinian and Saipan on April 15. Tropical storm winds started 1900ChST April 13 and ended just before 1300ChST April 16. Strong westerly tropical storm winds were recorded on Guam. The Apra Harbor Tide Gauge recorded a max wind of 58 mph at 1100ChST April 14 with a gust of 74 mph at 0155ChST April 15. Guam International Airport reported sustained winds of 55 mph at 2255ChST April 14 with a max gust of 87 mph at 1542ChST April 14. Pago Bay Tide Gauge reported a max water level of 2.03 feet (MHHW) at 0612ChST April 14. Lowest pressure measure on Guam was 976.0 mb (MSLP) at the Dandan RAWS near Inal��han at 2200ChST April 14. NWS Storm Survey around Guam saw extensive coastal inundation. On the east side of Guam near Talo'fo'fo, coastal run-up to 15.67 feet was recorded as the likely absolute max, with 5.50 ft and 9.00 ft of coastal run-up measured at Inal��han. On the west side of Guam 9.58 ft to 10.85 feet was measured at Asan, near the War in the Pacific Park. This flooding pushed sand up and across to Route 1 (Marine Corp Drive), along the stretch of road from Asan and northward to near Hag��t��a, the...