Forecasters give a central Pacific low a 90% chance of becoming a tropical depression within a week

A low-pressure area several hundred miles southeast of the Big Island of Hawaii carried a 90% chance of becoming a tropical depression in the outlook the Central Pacific Hurricane Center issued at 2:00 p.m. Hawaii time on Nov. 5. The disturbance, labeled CP95, is forecast to drift west-northwest to west at 10 to 15 mph and pass well south of the Hawaiian Islands. Forecasters wrote that a depression is expected to develop by early Friday.

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The product comes from the Honolulu-based hurricane center, which publishes it under the National Hurricane Center’s Miami umbrella and covers the ocean between 140 degrees west and the International Date Line. Forecasters Evans and Blake signed the Nov. 5 text. A day earlier the same system stood at 60% over 48 hours and 70% over seven days, so the newest outlook lifted both figures to 90%.

CP95: no center yet, but organizing southeast of the Big Island

In the Nov. 5 Central Pacific outlook, forecasters describe a low producing showers and thunderstorms with signs of organization but no well-defined center. Their wording that “a tropical depression is expected to develop by early Friday” is firmer than the previous evening’s language, which called formation likely within days. The 48-hour and seven-day odds are now identical at 90%, and both carry a “high” rating, which tells readers that forecasters expect the change to happen soon rather than slowly over the week.

The track matters to Hawaii residents. With a west-northwest to west motion at 10 to 15 mph, the low is projected to stay well south of the island chain, and the outlook text mentions no watch or warning for any island. Forecasters did not publish a position or wind estimate, because no advisory exists yet, so the 10 to 15 mph forward speed and the “several hundred miles” distance from the Big Island are the only geography the Nov. 5 text offers. Residents on the islands will mostly see the system as a line on the outlook map until it earns a number.

Two outlook cycles, 60% and 70% rising to 90%

The earlier product, the outlook issued at 8:00 p.m. Hawaii time on Nov. 4, described a broad low far southeast of Hawaii and gave 60% through 48 hours, rated medium, and 70% through seven days, rated high. Forecaster Blake wrote that conditions appeared favorable and that a depression was likely to form within days while the system moved west to west-northwest at the same 10 to 15 mph. About 18 hours later the 48-hour figure had climbed by 30 points and the seven-day figure by 20.

A jump of that size means the satellite presentation improved faster than the first outlook allowed for. It also moves the story from forecast to procedure: once a depression forms, the center begins numbered advisories with a track and intensity forecast, and the Nov. 5 text does not yet include any.

The odds are a probability of formation, not a forecast of strength. A tropical depression has sustained winds of 38 mph or less, and the outlook says nothing about the low becoming a named storm.

A second Pacific area off Central America, and a gale-force low near Bermuda

The same Nov. 5 text tracks a separate broad low offshore Central America. The eastern Pacific outlook from the previous evening had it at 40% over 48 hours and 60% over seven days. In the Nov. 5 text the figure is 40% through both windows, with forecasters saying gradual development is possible and a depression could form by the weekend as the low drifts north. Heavy rain is possible across parts of Central America through the weekend whether or not it organizes.

In the Atlantic, a gale-force non-tropical low a few hundred miles south of Bermuda has a 30% chance of taking on subtropical characteristics within 48 hours. Upper-level winds are expected to turn unfavorable late in the weekend, and gale warnings are carried in the National Weather Service High Seas Forecasts.

El Niño years and late-season storms near Hawaii

A late-season system fits the background pattern. The National Hurricane Center’s climatology pages link moderate to strong El Niño years with more Central Pacific tropical cyclone activity and with late-season storms. Records from 1971 to 2008 show 163 systems in the basin: 58 hurricanes, 46 tropical storms and 59 tropical depressions. The page adds that storms which never reach land can still do considerable damage through wind and surf.

This year the Pacific is primed. The Climate Prediction Center’s Oct. 8 ENSO discussion kept an El Niño Advisory in effect, put the Niño-3.4 index at plus 2.1 degrees Celsius, and said a strong-to-very-strong event was likely through January-March 2027 with a chance above 83%. The same discussion listed sea surface temperature anomalies above plus 4.0 degrees in parts of the eastern equatorial Pacific, Niño-3 at plus 3.0 and Niño-1+2 at plus 3.9, and flagged October-December as the window with the highest odds of a historic-strength event.

Its next update is due Nov. 12, and the Central Pacific Hurricane Center’s next outlook will show whether CP95 crossed the line into a numbered depression first.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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