In a big shift on Tuesday, the AI-based camp of hurricane models – led by Google’s bellwether DeepMind – latched on to a new candidate for development next week in the Atlantic, a fresh tropical wave trailing the disturbance now dubbed 92L that the National Hurricane Center has given a high chance of development in the coming days.
While NHC continues to assign 92L high odds of becoming a tropical depression or tropical storm in the next few days, forecast models have pared back their already-lukewarm long-term interest in the system, especially as it approaches the islands this upcoming weekend.
In Tuesday’s newsletter we discussed two scenarios for 92L: 1) a (more likely) weaker system (tropical depression or low-end tropical storm at most) taking a westward trajectory into the Caribbean or over the Lesser Antilles, the Virgin Islands and Puerto Rico for late weekend into early next week or 2) a (less likely) strengthening scenario curving north of the islands into early next week.
Today the stronger, farther north scenarios are effectively off the table. Though 92L isn’t too far removed from becoming a tropical depression or named storm, it’s surrounded by a slug of dry air that’ll be a thorn in its side for much of this week. By the time it reaches the eastern Caribbean, a firehose of wind shear should give it a knockout punch, and it’s unlikely it survives the weekend.
For the drought-stricken islands of the Caribbean – including Puerto Rico and the U.S. Virgin Islands – the system could bring beneficial rains this weekend into early next week.
As with any tropical system, the risk for locally heavy rain exists, but at this time it’s not expected to pose a widespread threat as it passes through this weekend into Monday.
AI models quickly latch on to the next wave
The AI models on Tuesday quickly turned their attention from 92L to a fresh new wave rolling into the eastern Atlantic from Africa. NHC introduced this system in their tropical outlook Tuesday evening, starting out with low odds of formation this week.
Unlike its counterpart 92L to the west, the AI models are much more bullish on this next wave strengthening down the line, especially next week as it approaches the central Atlantic.
Both Google’s DeepMind and the European’s AI-based modeling system show more interest in the long-term prospects of this new wave. We’re still in the early innings and the conventional physics-based models haven’t jumped on the bandwagon just yet. We’ll see if the long-range signal sticks with the AI models, but for now we have plenty of time to follow this one.
Regardless, the uptick in activity is a good reminder that we’re turning the corner into the most active 6-week stretch of the Atlantic hurricane season. While we expect lower overall activity this season due to El Niño, during peak season it only takes a small pocket of conducive conditions to get a strong hurricane, even during the down years.
Cristobal forms over the North Atlantic, overcoming the odds and scooping the deep tropics
As we’ve discussed in newsletters this season, it’s a little easier pathway this season for quick-forming storms in the subtropics versus the traditional deep tropics due to El Niño.
A case in point is the broad area of low pressure in the open North Atlantic that had only 10% development odds yesterday but gathered enough organization early Wednesday to become Cristobal, the 3rd named storm of the Atlantic hurricane season.
Cristobal will be short-lived and poses no threat to land as it heads out to sea this week.
Hawai’i on alert for tropical impacts this weekend
A disturbance in the central Pacific about 1,000 miles southeast of Hawai’i was designated Potential Tropical Cyclone One-C (formerly Invest 93C) by the National Hurricane Center late Wednesday morning. A potential tropical cyclone is a system that hasn’t yet formed but is expected to do so and could bring tropical storm or hurricane conditions to land areas within 2 to 3 days.
The system is forecast to develop into a tropical storm later today or on Thursday, strengthen, and threaten the Hawaiian Islands by the weekend. The first name on the list for the Central Pacific hurricane season is Lala.
It’s difficult and unusual for a hurricane to strike Hawai’i from the east – largely due to water temperatures that typically drop off quickly near and north of the island chain – but this year waters are running much warmer than usual over the central Pacific. While it’s uncommon for hurricanes to hit Hawai’i, it’s not unheard of and strong hurricanes have struck the state in the past.
It’s too soon to know whether the system will be a hurricane when it nears the state early Saturday local time, but intensity guidance suggests it could be close (hurricane winds start at 74 mph), and residents and visitors across the state – from the Big Island to Maui, Oahu, and Kauai – will want to check back frequently on the forecasts in the days ahead.
As we mentioned in Tuesday’s newsletter, due to the state’s extreme geography, it doesn’t take as strong of a storm as it does on the mainland to cause problems, especially in populated areas like on Oahu where storm threats are less common.
Either way, folks should begin taking necessary precautions for an increasing threat of impactful weather and dangerous surf conditions from the system this weekend.
Thanks for another informative email.