In general, the Atlantic hurricane season is a late bloomer relative to its counterpart in the eastern Pacific.
On average, tropical activity in the eastern Pacific both starts earlier – which is why the hurricane season there begins on May 15th versus June 1st in the Atlantic – and ends sooner than in the Atlantic.
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By this point in the year, the Pacific has typically cranked out about a quarter of its tropical energy while the Atlantic has eked out a mere five percent of its total yearly tropical energy.
And while May and June hurricanes in the Atlantic are uncommon, they tend to be a regular occurrence on the Pacific side, which usually sees its first burst of tropical activity in July.
The Atlantic, on the other hand, typically doesn’t ramp up until late August.
So the uptick in activity we’ve observed in the eastern Pacific in July so far isn’t by itself unusual. What’s more curious is the strength, duration, and number of hurricanes that have formed.
Both Bonnie, a transplant from the Atlantic Ocean, and Darby were major (Category 3 or stronger) hurricanes, and both maintained hurricane strength for over 1,500 miles of their tracks through the Pacific.
All the activity has led to the fifth most active start on record for an eastern Pacific hurricane season (behind 1992, 1978, 1984, and 2015), and during a La Niña year nonetheless, when overall activity is usually dampened by less conducive environmental conditions.
Once-Hurricane Estelle in the Pacific continues to weaken as a tropical storm. It should lose any remaining thunderstorms by tomorrow as it heads toward the eastern Pacific graveyard.
The Pacific should settle down for the rest of the week and, with the Atlantic staying quiet into the weekend, we may see our first break from tropical activity on this side of the world in over three weeks.
As we discussed in Sunday’s newsletter, the Atlantic will become more conducive to storminess next week as the stagnant upper wind pattern of the past few weeks begins to shift away.
While we don’t have anything specific to hang our hat on just yet, we’ll keep an eye to the central and eastern Atlantic, as more robust disturbances roll through the deep tropics.