FXPQ50 PGUM 162129 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 729 AM ChST Sat Oct 17 2026 .Marianas Update... Typhoon Champi continues to approach. Most models now take it close to Guam, so they appear to be converging on a solution. It's satellite presentation has been improving, with the center clearing slightly in an attempt to form an eye. Forecast was changed slightly Saturday to bring scattered heavy showers in by the afternoon with the rest remaining unchanged. Damaging winds are anticipated to begin late tonight around midnight. && .Hydrology... As Typhoon Champi approaches, it will bring, among other things, copious rainfall. Amounts for Sunday and Monday are expected to reach 4 to 6 inches at Tinian and Saipan, 10 to 15 inches at Rota, and 12 to 20 inches at Guam. After coordinating with the National Water Center regarding their national Flood Hazard Outlook, Tinian and Saipan are Limited, Rota is Considerable, and Guam is Locally Catastrophic. The Flash Flood Watch will likely be upgraded to a Flash Flood Warning tonight if not sooner. && .Tropical Systems... Champi has just been upgraded to Typhoon 29W. Champi is centered near 12.0 degrees north and longitude 149.6 degrees east. It has maximum sustained winds of 85 mph. Champi is moving to the west-northwest at 15 mph. Champi is currently about 340 miles east-southeast of Guam. Champi is currently expected to pass slightly south of the island of Guam. This is the general track of many of the AI-enhanced models. The physics based models are taking Champi either over or just north of Guam. It's starting to look like a close hit will be inevitable, the question will be, as it often is, how close? 10 miles away can be a lot different from 30 miles. For more information on Typhoon Champi, please see the Tropical Cyclone Public Advisory issued by the National Weather Service under WMO header WTPQ32 PGUM and the Tropical Cyclone Warning issued by the Joint Typhoon Warning Center under WMO header WTPN32 PGTW. && .Eastern Micronesia... There are three major features in the region, the monsoon trough, a buffer circulation to the south of majuro, and a low that is near the Date Line. The monsoon trough is currently over northern RMI, (over Enewetak, Bikini, Rongelap, Wotje and north of Majuro) and intersects with the low near the Date Line. The buffer circulation is aiding in the convection near Majuro by tightening the convergence zone. This zone is producing scattered showers and isolated thunderstorms. Flare ups of convection can be expected through middle of next week. For Pohnpei and Kosrae, a short lull in showers is expected for the next few days, then as the buffer circulation moves more northward showers are expected to return near the beginning of next week. These showers are anticipated to remaining through at least the middle of next week. As for the seas, near Pohnpei, the primary swell will be out of the south for the next day or so as Typhoon Champi moves further away, then the trade swell is expected to become the dominate swell. Overall seas are expected to be the highest near Pohnpei at 6 to 7 feet, and tapering down 4 to 5 feet to the east of Majuro. Winds are expected to remain light to moderate through the middle of next week. && .Western Micronesia... A Small Craft Advisory remains in effect for Chuuk. The main weather maker for the region is Typhoon Champi to the north of Chuuk. Chuuk is in the monsoonal inflow notch. Scattered showers and isolated thunderstorms are expected with winds of moderate to strong. These conditions are expected to last through the early morning hours. Once Champi moves further west, conditions are are expected to improve as early as mid to late Sunday morning. Benign weather is expected to return through the middle of next week. For Palau and Yap a benign weather is expected through the middle of next week. For the seas at Palau and Yap, a north swell produced by Champi is expected to build in as Champi builds in strength and moves westward and start making its presence known as early as Sunday night into Monday morning. Seas are expected to be near 7 to 8 feet near Chuuk and tapering down 3 to 4 feet near Palau. && .Prev discussion... /issued 853 PM ChST Fri Oct 16 2026/ Marianas Synopsis... Partly cloudy skies with isolated showers and gentle to moderate trade winds prevail across the Marianas. Tropical Storm Champi, currently east of the Marianas, continues its trek toward the islands. Discussion... The big story, TS Champi. Champi continues to slowly strengthen east of Guam as it moves west. The latest forecast track brings Champi over northern Guam Sunday morning, with tropical storm force winds arriving before midnight Saturday. Therefore, a Typhoon Warning was issued for Guam and Rota, with a Tropical Storm Warning issued for Tinian and Saipan, with a Typhoon Watch continuing in case Champi makes a turn to the north. The forecast for tonight and Saturday maintains the current drier pattern. However, that will change drastically as Champi approaches. Tropical storm force winds, increasing heavy showers and thunderstorms will move into the region Saturday evening. By Sunday morning, we can expect at least category 2 typhoon force winds at Guam, category 1 at Rota and strong tropical storm winds at Tinian and Saipan. Winds and convection will continue over the islands through Sunday night, with tropical storm conditions possibly ending Sunday night, after midnight. After Champi exits the region, a dry pattern looks to move into the region around Monday and continuing through the end of the week. Residents of the Marianas should make sure that they are prepared for typhoon force sustained winds of up to 105 mph. Stay safe and follow our forecasts for any updates as they occur. Marine... Marine and surf conditions will deteriorate rapidly, beginning Saturday evening as TS Champi approaches. A Typhoon Warning is in effect for Guam and Rota waters, with a Tropical Storm Warning now in effect and Typhoon Watch remaining in effect for Tinian and Saipan. Combined seas will remain at or below 7 feet through Saturday morning, then begin to build as a large east swell from Champi enters the waters. As Champi moves through the waters, seas could reach as high as 35 feet near the center of Champi, depending on how much Champi strengthens. Seas will be lowest for Tinian and Saipan waters, but still reach around 19 feet as Champi moves through. The large seas produced by Champi are expected to produce dangerous/deadly surf and rip currents, as well as coastal flooding, with inundation of 5 feet or more near the eye of Champi, and as high as 1 to 3 feet at Tinian and Saipan. Surf could reach as high as 26 feet at Guam and 19 feet at Tinian and Saipan. Rota can expect around 20 feet. Seas could remain hazardous through Monday, after Champi departs the region. Tropical Systems... As of 700 PM ChST, the center of Tropical Storm Champi (29W) was located near 12N152E, which is about 510 miles east-southeast of Guam. It was moving west at 13 mph, with maximum sustained winds having increased to 60 mph near the center. Champi is expected to make a slight turn toward the west-northwest with a slight increase in forward speed through Saturday. This general forecast track will take Champi close to, or over, Guam Sunday morning. Champi is expected to go through a period of rapid intensification over the next 24 hours, becoming a typhoon by Saturday and strengthening further thereafter. Winds and rain will come in rapidly, with winds becoming dangerous and life threatening very soon after onset. Do not let a false sense of normalcy now dictate your actions tomorrow; prepare NOW! For more information, please refer to the bulletins issued by the Joint Typhoon Warning Center under WMO header WTPN32 PGTW, and by the National Weather Service in Tiyan, Guam under WMO header WTPQ32 PGUM. Eastern Micronesia... Tropical Storm Champi continues to move away from the region, which will allow showers to become isolated at Pohnpei Saturday night. Kosrae will mainly see isolated showers as well through the weekend, before increasing next week. However, at Majuro, the monsoon trough is lingering just to the north, with a another tropical circulation east of the Date Line poised to move into the region early next week. This will keep scattered showers going through the forecast period there. As Champi moves away, winds and seas will slowly decrease. Seas will return to the 4 to 6 foot range at Pohnpei and Kosrae, remaining at these values for Majuro. Western Micronesia... The main forecast challenges were maximum wind gusts at Chuuk, and swell direction and height for Yap and Palau as current TS Champi passes north of there. For now, kept wind gusts to 30 knots at Chuuk but mentioned a few higher gusts could occur, but with some uncertainty as to when during the next 24 hours Champi begins its RI (Rapid Intensification) cycle. Therefore a special weather statement remains in place along with a Small Craft Advisory for hazardous seas. will be elevated Then at Yap, focus was placed on trying to refine swell heights and directions, while introducing them at Palau Tuesday. Otherwise, look for isolated shower coverage at Palau and Yap to continue, becoming isolated at Chuuk by the end of the weekend. Gentle to fresh winds are expected at Chuuk, decreasing as we head into next week, while increasing at Yap during the same time. Palau will remain in the light to gentle range. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...Flood Watch through Sunday afternoon for GUZ001. Typhoon Warning for GUZ001. Coastal Flood Watch from this afternoon through late Sunday night for GUZ001. High Surf Warning from 5 PM this afternoon to 4 AM ChST Monday for GUZ001. MP...Flood Watch through Sunday afternoon for MPZ001>003. Typhoon Warning for MPZ001. Coastal Flood Watch from this afternoon through late Sunday night for MPZ001>003. High Surf Warning from 5 PM this afternoon to 4 AM ChST Monday for MPZ001>003. Tropical Storm Warning for MPZ002-003. Typhoon Watch for MPZ002-003. Marianas Waters...Typhoon Warning for PMZ151-152. Tropical Storm Warning for PMZ153-154. Typhoon Watch for PMZ153-154. && $$ Tropical Update: Stanko East and West Micronesia Update: Bowsher Marianas Update: Ogle Marianas: Kleeschulte East/West Micronesia: Doll Tropical: Montvila/Mesa DSS: Mesa