The two systems are currently far from major population centers, but their development underscores why forecasters continue to keep a close eye on the Pacific even as Norbert begins falling apart.
Norbert was located approximately 1,655 miles west of the southern tip of Baja California and roughly 1,290 miles east of Hilo, Hawaii, according to the latest forecast information.
The tropical storm was producing maximum sustained winds of about 45 mph, along with stronger gusts, while traveling west-northwest at roughly 14 mph.
But the atmospheric environment ahead of Norbert is becoming increasingly unfavorable.
Forecasters expect the cyclone to continue weakening as conditions make it more difficult for the storm to sustain the powerful thunderstorms surrounding its circulation.
If the forecast holds, Norbert is expected to deteriorate into a post-tropical remnant low by Tuesday.
The remaining circulation could then disappear altogether by Wednesday, bringing Norbert’s run across the Pacific to an end.
But another system is already taking shape farther east.
Tropical Depression Fifteen-E officially formed Sunday approximately 680 miles southwest of the southern tip of Baja California.
The newly organized depression was carrying sustained winds of roughly 35 mph, with stronger gusts, while traveling west at around 10 mph.
Forecasters expect Fifteen-E to accelerate somewhat while gradually shifting toward the west and west-southwest over the next couple of days.
More importantly, the system could strengthen quickly enough to become a tropical storm by early Monday.
If that happens, the cyclone would receive the next available name on the Eastern Pacific storm list: Odalys.
Before becoming Tropical Depression Fifteen-E, the disturbance was being monitored as Invest 97E. Its organization improved enough Sunday for forecasters to classify it as a tropical depression.
The possibility of another named storm naturally raises questions about Hawaii, particularly with both systems moving generally westward across the Pacific.
For now, however, forecast guidance provides some reassuring news.
Neither Norbert nor Fifteen-E is currently expected to pose a direct hurricane threat to the Hawaiian Islands.
Computer models generally suggest the developing system will eventually run into the same kind of hostile environment now dismantling Norbert.
One of the biggest problems facing the storms is dry air.
Tropical cyclones depend on sustained areas of deep thunderstorm activity to remain organized and intensify. When dry air penetrates a storm’s circulation, it can choke off that activity and significantly weaken the system.
Current modeling indicates that Fifteen-E could encounter those deteriorating conditions long before reaching Hawaii.
“All reliable forecast models have the storm dissipating before it ever comes close to being in the vicinity of Hawaii,” said the forecast center.
That is welcome news for residents of the islands, although meteorologists will continue following the system as it makes its way across the vast Pacific.
Long-range tropical forecasts can evolve as steering currents, ocean temperatures, wind shear, and atmospheric moisture levels change.
Norbert, meanwhile, appears increasingly likely to fade harmlessly over open water.
Assuming the current projections remain intact, neither system is expected to deliver a direct hit to Hawaii.
Still, the emergence of two systems in relatively quick succession shows that the Eastern Pacific remains capable of producing organized tropical activity well into hurricane season.
The enormous distances involved can also make Pacific storms worth watching for days at a time, even when the initial forecast keeps them far from land.
For residents along vulnerable coastlines, the latest activity serves as another reminder that hurricane season is not over simply because a storm currently appears unlikely to make landfall.
Forecast tracks can shift, storms can strengthen or collapse faster than anticipated, and environmental conditions thousands of miles away can determine whether a tropical system survives.
For the moment, the outlook is relatively favorable.
Norbert is weakening and expected to disappear, while Fifteen-E may briefly become Tropical Storm Odalys before encountering increasingly hostile conditions of its own.
The National Hurricane Center will continue tracking both systems and updating its forecasts as their strength and movement become clearer.
