Typhoon In-fa tracks over the remote northern Marianas as Category 4 storm after peaking as a super typhoon
Typhoon In-fa was forecast to pass over or just north of Agrihan on Friday night with gusts up to 150 mph. Saipan and Guam are outside the warning area.
At a glance
- In-fa was downgraded from super typhoon to Category 4 on Friday afternoon, with its centre forecast to pass over or just north of Agrihan that evening.
- A typhoon warning covered Agrihan, Pagan and Alamagan; Saipan, Tinian, Rota and Guam were outside it.
- Forecasters warned of winds of 80 to 100 mph, gusts up to 150 mph, and surf of 30 to 40 feet on east-facing reefs.
- No damage or casualty reports from the islands had been confirmed at publication.
Typhoon In-fa was forecast to cross the far north of the Northern Mariana Islands on Friday night local time as a Category 4 storm, hours after weakening from super typhoon strength. Its centre was expected to pass over or just north of Agrihan, with Pagan and Alamagan also under a typhoon warning.
The three islands are remote and sparsely populated, and the US territory's main population centres on Saipan, Tinian and Rota were outside the warning. No reports of damage or casualties from the northern islands had been confirmed when this report was published. Communications with such remote places can take time to establish.
How fast In-fa grew
| When (local time) | Strength | Note |
|---|---|---|
| Monday, Oct 26, morning | About 90 mph | More than 1,200 miles east of Guam |
| Monday evening | Category 4 | Rose from Category 1 within hours |
| Tuesday, Oct 27, morning | Category 3, 125 mph | Almost stationary over cooler water |
| Later in the week | Super typhoon | Classified by US military forecasters |
| Thursday, Oct 29, 5 p.m. | 130 mph | Moving west at 18 mph, per CNMI emergency officials |
| Friday, Oct 30, afternoon | Category 4 | Downgraded from super typhoon |
The danger on Agrihan, Pagan and Alamagan
The US National Weather Service warned of destructive winds of 80 to 100 mph, with gusts of up to 150 mph on Pagan and Alamagan. Agrihan faced the greatest threat. Surf was expected to build to 30 to 40 feet along east-facing reefs.
Emergency officials said typhoon-force winds reached up to 50 miles from the centre and tropical storm-force winds up to 125 miles. Gov. David Apatang kept the three islands under Typhoon Condition II ahead of the storm, meaning winds of 74 mph or more were expected within 24 hours.
What Saipan, Tinian, Rota and Guam should expect
Those islands were spared the worst of the forecast track, though not every hazard. A high surf warning covered north- and east-facing reefs of Saipan and Tinian, and forecasters warned of dangerous surf and rip currents across the Marianas into the weekend. Swimmers, fishers and boat operators should stay away from exposed reefs until the warnings are lifted.
Guam's forecast stayed mostly fair, with outer effects possible. Forecasters had said early in the week that a more westerly track would be "a bigger problem for Saipan and Tinian", but that shift did not appear in the later forecasts.
A busy season in a strong El Niño year
In-fa formed in a year of strong El Niño, when the western Pacific tends to produce stronger storms further east. Earlier reporting citing US climate scientists puts the chance of a direct typhoon strike on Guam at about one in three during a strong El Niño, compared with about one in seven in a typical year.
The storm also follows Super Typhoon Champi, the year's strongest storm so far, which hit Taiwan and moved north towards Japan earlier this season.
Where In-fa goes next
The Weather Service expected In-fa to turn northwest and slow on Saturday, possibly becoming almost stationary by Sunday afternoon. Emergency officials said it could weaken to Category 3 by Saturday afternoon. A storm that stalls over open water is hard to forecast, so its later track remains uncertain.
The first aerial or radio reports from Agrihan, Pagan and Alamagan will show what the storm actually did, and this report will be updated when officials release them.
Questions people are asking
Is Typhoon In-fa going to hit Saipan or Guam?
Forecasts kept the core of the storm well north of Saipan and Tinian, and Guam was forecast to have mostly fair weather. High surf and rip currents remained a danger across the Marianas into the weekend.
