Tropical Storm Champi is strengthening east of Guam, prompting a typhoon watch across the Mariana Islands as forecasters track a potential path toward typhoon status this weekend.
The system formed on October 15, quickly upgrading to Tropical Storm Champi. By early Friday morning, official advisories placed the center about 800 miles east of Guam, moving west at 12 miles per hour with sustained winds of 40 miles per hour. Forecasters project a steady intensification into a typhoon as the system narrows the distance to the Marianas.
With the Northern Mariana Islands and Guam in the path of Tropical Storm Champi, locals are preparing for further destruction brought by the third tropical cyclone to affect the area since April. The two U.S. territories are still recovering from earlier storms, with some residents facing the possibility of being displaced for the third time in six months. Super Typhoon Sinlaku struck the area initially on April 14, followed on July 6 by Super Typhoon Bavi, which made landfall on Rota as the strongest storm in the island’s history while damaging winds swept across Guam, Tinian, and Saipan.
At 5:00 am ChST, Champi was centered 800 miles east of Guam near 11.6N 156.5E, moving west at 12 mph with maximum sustained winds of 40 mph. A Typhoon Watch remains in effect for Guam, Rota, Tinian, and Saipan, alongside a flood watch issued for Guam. The Joint Typhoon Warning Center assessed Champi at 35 knots at 15:00 UTC on October 15. A typhoon watch took effect Thursday afternoon for Guam, Rota, Tinian, and Saipan, with predicted peak intensity levels varying between a Category 1 and a Category 3 typhoon according to different forecasting outlets. Earlier in the day at 1 p.m., the depression sat roughly 970 miles east of Guam, tracking west-northwest at 13 mph with maximum sustained winds of 40 mph. Forecasters expected the depression to maintain that strength through Thursday night and begin strengthening Friday, potentially becoming a tropical storm Saturday and a typhoon Sunday.
Guam Homeland Security Declares COR 3 as Damaging Winds Approach
Local authorities moved quickly to raise preparedness levels across the island chain. Governor Lou Leon Guerrero placed Guam under Condition of Readiness 3, which signals that tropical storm-force winds of 39 miles per hour or greater could arrive within 48 hours. Placing Guam in COR 3 gives families, businesses, and government agencies time to prepare before conditions deteriorate.
29W has developed into Tropical Storm Champi and will strengthen at a moderate pace over the next 3 to 4 days to near super typhoon. Guam and parts of the Northern Mariana Islands are in the direct path and should expect category 2 equivalent conditions this weekend. pic.twitter.com/oaOEN0kiBy
Governor Lou Leon Guerrero urged everyone to take the storm seriously, secure their homes, and make sure loved ones have what they need, noting that preparing now can make all the difference in the days ahead. The governor also stressed that residents should stay out of the water at this time, stating that going into the water during storm conditions not only puts individuals at risk but also risks the lives of first responders called to rescue them. Candidates and campaigns were urged to remove and secure campaign signs before hazardous winds arrive.
The American Red Cross began moving disaster teams and supplies into the region ahead of the storm. Charles Blake noted that repeated storms have stretched disaster response capabilities.
When you get hit with multiple storms, one right after the other, and you don’t get time to fully recover from those storms, there’s going to be some gaps.
Charles Blake, American Red Cross coordinating officer
People across the islands are currently setting up shelters, and inhabitants have been advised to gather at least a 48-hour supply of food, water, fuel, and necessary medicines. Blake warned that power, water, and fuel shortages could complicate recovery efforts, stating that while they cannot do everything for everybody, they will do their best to meet people’s needs and meet them where they’re at. The Red Cross is finalizing plans to support sheltering after the storm’s impact, relying on contributions from the Annual Disaster Giving Program and Disaster Responder Program members to maintain a reliable funding base for immediate disaster relief services.
Diverging Forecast Models Track Champi Through the Marianas
While the threat to the Marianas is immediate, meteorological agencies offer varying projections on the storm’s peak intensity and exact trajectory. Public Advisory No. 1 from Guam Homeland Security and the Office of Civil Defense advised residents to prepare for at least a Category 2 typhoon, a step up from previous guidance, while also describing the forecast as a storm peaking at the high end of Category 1 as it approaches. The National Weather Service anticipates the system will pass very near or over Guam as a category 2 typhoon by Sunday. However, Paul Stanko, a meteorologist, noted that intensity forecasts remain subject to change, estimating that winds near the center could reach about 115 mph as the storm passes, representing a low-end Category 3 typhoon.
of course the intensity forecast could always change.
Paul Stanko, meteorologist
Other agencies project an even stronger system. Stanko also mentioned that computer models are indicating another potential system behind 29W, though it does not exist yet and remains a little bit speculative.
Forecasters point to a divide between traditional physics-based computer models and artificial intelligence-enhanced projections. Computer simulations generated possible paths ranging from south of Guam up to northern Guam and through the channel between Guam and Rota, creating uncertainty regarding which specific locations will take a direct hit from the eye of the storm. Additional shifts in forecast track, timing, and tropical cyclone intensity will occur with each subsequent forecast cycle.
Torrential Rains and Twenty-Foot Seas Threaten Low-Lying Coastal Areas
Beyond wind hazards, forecasters warn of severe flooding and marine impacts. A flood watch covers Guam, Rota, Tinian, and Saipan, with total rainfall accumulations expected to reach 5 to 10 inches, and locally higher amounts possible. Flooding is possible in urban, low-lying, and poorly drained areas.
Coastal areas face significant storm surge inundation, with surf forecast to increase from 3 to 5 feet on October 17 to 7 to 9 feet that evening, before reaching 15 to 20 feet on the morning of October 18. Depending on Champi’s track, coastal inundation of 2 to 3 feet is possible, with wave runup reaching 12 feet. Marine conditions are forecast to deteriorate rapidly over the weekend, with open-ocean seas expected to build rapidly from Saturday into Sunday and rise above 20 feet during Champi’s closest passage, with dangerous conditions potentially continuing into October 19.
Local officials issued strict warnings against entering the water during the heavy surf conditions, emphasizing that all reefs could be exposed to dangerous conditions, although it is too early to determine which will be affected the most. Conditions Thursday and Friday were expected to remain relatively calm before regional weather and sea conditions deteriorate through the day on Saturday.
Further afield, the Central Weather Administration in Taiwan monitored Tropical Storm Champi as it moved west-northwest after strengthening from a tropical depression Thursday east of Guam. CWA forecaster Hsieh Pei-yun stated that the storm was still more than 4,200 kilometers from Taiwan, while CWA forecaster Cheng Chieh-jen noted that the storm’s ultimate trajectory depends on a Pacific high-pressure system. Additional reports from international meteorological agencies noted that Champi formed alongside monitoring of Hurricane Trudy in the Eastern and Central Pacific as part of an unusually active storm season marked by an exceptional El Niño.