The Eastern Pacific is operating on overdrive, and Hawaii is officially in the crosshairs.
Meteorologists are tracking Potential Tropical Cyclone One-C (PTC 1-C), a system currently spinning just over 1,000 miles east-southeast of Honolulu. By Friday, this system is expected to strengthen and claim the name Hernan.
But this isn't just a local weather warning—it is a textbook example of what happens when record-setting ocean temperatures collide with a powerful global climate driver.
Here is what you need to know about the incoming storm, why Hawaii is facing a rare threat, and the massive climate forces pulling the strings behind the scenes.
The Immediate Threat: What Hawaii Can Expect
PTC 1-C is projected to strengthen into a powerful tropical storm—and potentially even a hurricane—as it closes in on the island chain.
- The Timeline: Heavy rains are expected to slam the Big Island on Friday, marching into Maui by the start of the weekend, and engulfing the rest of the Hawaiian Islands through Sunday.
- The Rainfall: Forecasters are warning of widespread totals between 5 and 10 inches, with isolated mountainous areas potentially seeing a staggering 20 inches of rain.
- The Risk: Rainfall of this magnitude triggers immediate concerns for life-threatening flash flooding and mudslides.
- The Winds: While water is the primary hazard, gusty winds are likely to down trees and knock out power grids across the islands.
Direct hurricane landfalls in Hawaii are historically rare. The NOAA Historical Hurricanes Tracks database notes that only two named storms have ever made landfall on the Big Island at tropical storm strength. The most recent major scare was Hurricane Hone in August 2024, which bypassed the Big Island by 50 miles but still unleashed damaging outer bands.
Why the Pacific is Boiling Over
If it feels like we are seeing an unusual amount of tropical activity, that’s because we are.
With Hernan poised to become the eighth named system of the Eastern Pacific season, the region is running nine days ahead of schedule. Typically, the eighth named storm doesn't emerge until late August.
So, why the sudden rush? It comes down to two major catalysts:
- A Strengthening El Niño: This climate phenomenon alters wind patterns globally, reducing wind shear in the Pacific and allowing storms to organize and intensify without being ripped apart.
- Record-Setting Sea-Surface Temperatures: Warm water is fuel for hurricanes. Ocean temperatures are hovering at historic highs, acting as a high-octane booster shot for passing storms.
We are currently in the first of three historic seasonal peaks for the Eastern Pacific. With subsequent peaks expected in early and late September, Hernan is highly unlikely to be the last threat Hawaii faces this year.
The Global Picture: A Tale of Two Oceans
While the Pacific is raging, the Atlantic basin is telling a completely different story.
Though Tropical Storm Cristobal recently formed, it is quickly dissolving over cool northern waters. Behind it, meteorologists are watching two tropical waves—dubbed Invest 92L and Invest 94L.
Surprisingly, these Atlantic systems pose very little threat to the U.S. mainland. The same El Niño that is supercharging the Pacific is producing hostile vertical wind shear (between 30 to 50 knots) over the Caribbean, effectively acting as a shield that tears Atlantic storms apart.
In a twist of climate irony, the arrival of Invest 92L might actually be a blessing. If it remains a weak system, it could bring much-needed rainfall to the Caribbean islands, which are currently battling severe droughts and critical water shortages in places like Puerto Rico.
The Bottom Line
As PTC 1-C inches closer to Hawaii, residents and travelers are being urged to finalize emergency plans. In an era of record-hot oceans and shifting atmospheric patterns, "unprecedented" weather is rapidly becoming our new normal. Stay tuned to local advisories as the weekend approaches.
