THE WEATHER BEAT · OCT 16

Champi watch becomes a Typhoon Warning for Guam and Rota, with a Tropical Storm Warning for Tinian and Saipan

Tropical Storm Champi is 590 miles from Guam and moving west at 24 mph; a Typhoon Warning is up, with 12 to 20 inches of rain possible on Guam.

By the Weather Rock October 16, 2026, 7:33 a.m. · 6 min read

Guam, Hagatna seen from Fort Santa Agueda — Hagatna, Guam, seen from Fort Santa Agueda, photographed on 3 July 2010. Photo: Abasaa, Wikimedia Commons, Public domain.

Key points

As of 4:11 p.m. ChST Friday, the Weather Service in Tiyan has a Typhoon Warning for Guam and Rota. Tinian and Saipan have a Tropical Storm Warning, and the Typhoon Watch there stays in place. Yesterday all four islands were under a watch only.
Champi is now a tropical storm. At 2 p.m. ChST it was about 590 miles east-southeast of Guam, moving west at 24 mph with 50 mph winds. The office expects it to become a typhoon by Saturday and to pass close to or over Guam on Sunday morning.
A Flood Watch says 12 to 20 inches of rain are possible on Guam. A High Surf Warning has surf building to as high as 26 feet on Guam's reefs, and a Coastal Flood Watch says inundation of up to 5 feet is possible there.

Yesterday, and this afternoon in the Marianas

Yesterday morning Champi was a tropical depression about 890 miles east of Guam, moving at 10 mph. By Friday afternoon it had become Tropical Storm Champi. It was moving more than twice as fast and had covered about 300 of those miles. At 4:11 p.m. ChST the Weather Service office in Tiyan upgraded its watches. Guam and Rota now have a Typhoon Warning. Tinian and Saipan have a Tropical Storm Warning, and their Typhoon Watch continues.

The office's local statement expects quiet weather across the Marianas on Friday night. Showers and wind should pick up Friday afternoon, local time, and conditions should get much worse coming into Saturday night. The statement says Champi is expected to intensify rapidly over the next 24 hours and become a typhoon by Saturday. It also says the wind and rain will arrive quickly, and that winds will turn dangerous soon after they start. The office asks people not to read Friday's calm as a sign of the weekend, and to prepare on Friday.

The coastal waters products, issued at 4:51 p.m. ChST, give the ocean side. Typhoon conditions are expected in Guam and Rota waters, with damaging winds starting Saturday night and destructive winds Sunday morning. Seas there could reach 35 feet at closest passage. Tinian and Saipan waters expect tropical storm conditions, typhoon conditions are possible, and seas could reach 25 feet. The office says the exact path "remains subject to change."

Item	Value (NWS Tiyan, 2 p.m. ChST Fri 16 Oct)
System	Tropical Storm Champi (29W)
Position	11.4N, 153.3E
Distance	about 590 miles east-southeast of Guam, about 300 miles north-northeast of Chuuk
Movement	west, 265 degrees, 24 mph
Intensity	50 mph
Forecast	typhoon by Saturday; close to or over Guam Sunday morning
Seas at closest passage	up to 35 ft Guam and Rota waters, up to 25 ft Tinian and Saipan waters
A day earlier (7 p.m. ChST Thu)	Tropical Depression, about 890 miles east of Guam, 10 mph, 35 mph winds

Source: NWS Tiyan GU Typhoon Warning local statement, 4:11 p.m. ChST 16 Oct 2026; coastal waters Typhoon Warning and Tropical Storm Warning, 4:51 p.m. ChST 16 Oct 2026; Thursday figures from the 15 Oct local statement as reported in this Journal.

Today, officially: rain and surf

The Flood Watch from 2:31 p.m. ChST Friday covers Guam, Rota, Tinian and Saipan through Sunday afternoon. It expects heavy rain from Saturday night into at least Sunday. Possible totals are 12 to 20 inches for Guam, 10 to 18 inches for Rota, and 8 to 12 inches for Tinian and Saipan. On Tuesday the office's Hydrologic Outlook gave 5 to 8 inches, so the forecast totals have more than doubled since then.

The High Surf Warning and Coastal Flood Watch, both from 3:12 p.m. ChST, cover all four islands. Surf on east-facing reefs should be 7 to 9 feet on Saturday afternoon. It then builds to as high as 26 feet for Guam, 20 feet for Rota and 19 feet for Tinian and Saipan, and spreads to south-facing reefs through Sunday afternoon. The watch says coastal inundation is possible: up to 5 feet on Guam, 2 to 4 feet on Rota, and 1 to 3 feet on Tinian and Saipan. The surf warning runs from 5 p.m. Saturday to 4 a.m. Monday, ChST.

The Weather Service's advice is plain. Bring small loose objects indoors, find suitable shelter, and stock a few days of food and water. Stay out of the water and off jetties and piers. Federal preparedness guidance is at ready.gov.

Product	Issued (ChST, Fri 16 Oct)	Covers	Key line
Typhoon Warning	4:11 p.m.	Guam, Rota	typhoon likely near Guam and Rota
Tropical Storm Warning, Typhoon Watch	4:11 p.m.	Tinian, Saipan	watch continues alongside the warning
Typhoon Warning, coastal waters	4:51 p.m.	Guam and Rota waters	seas as high as 35 ft
Tropical Storm Warning, coastal waters	4:51 p.m.	Tinian and Saipan waters	seas as high as 25 ft
Flood Watch	2:31 p.m.	all four islands, through Sun afternoon	12 to 20 in Guam
High Surf Warning, Coastal Flood Watch	3:12 p.m.	all four islands	surf to 26 ft Guam, inundation up to 5 ft

Source: NWS Tiyan GU products via api.weather.gov, fetched 11:33Z 16 Oct 2026.

This is a summary of official warnings, not emergency information. For live warnings see weather.gov and your local officials. NWS Guam: https://www.weather.gov/gum/

The rock's live forecast for the places in this story