It’s been a very quiet first half of July across the Atlantic, as we previewed it would be back on July 1st. It’s been 26 days since we’ve had an active system (short-timer Arthur on June 17th) anywhere in the Gulf, Caribbean, or wider Atlantic and since June 30th – when we were monitoring an innocuous frontal low for negligible development odds – that the National Hurricane Center has outlined anything on its tropical outlook map.
July is often a quiet month so that alone isn’t terribly unusual. Even during what became busier hurricane seasons like in 2016, the National Hurricane Center had a blank outlook canvas for most of the month. Things get weirder when the quiet continues deeper into August (we know that feeling from recent hurricane seasons).
Still it’s been an unusually slow start – the least active start to a hurricane season since 2009 – and as we’ve covered extensively in this newsletter, the factors are aligning to make this one of the least active seasons in over a decade. Even so, it only takes one bad hurricane to make a bad year, so we stay vigilant.
Already-low odds of Gulf mischief early next week trend lower
Over the weekend, some of the newcomer AI models – notably the European Centre’s AI modeling system – showed an uptick in development odds for an initially non-tropical low pressure over the northeastern Gulf. The uptick garnered the typical frenzy among some social media circles (hopefully not yours!) mainly from the European’s deterministic (single-run) AI model, which advertised a hurricane-strength system for early next week over the northern Gulf in forecast runs beginning Sunday afternoon.
Of course, for regular readers of this newsletter, we know single-run models beyond a week aren’t credible sources unless they’re backed by strong evidence from multi-model ensembles (in this instance, it was undeniably not). Additionally, as we’ve discussed in previous posts, the Euro AI model has shown exactly zero skill in forecasting intensity, so intensity forecasts from that model should be taken with a healthy dose of skepticism.
Since its very bullish forecast Sunday, the Euro AI has quickly backed off its initially overheated forecasts.
Even the more level-headed ensembles, which, as we discussed in Monday’s newsletter, only supported low odds of development the past few days have trended lower in development chances next week.
Overall the atmosphere over the northern Gulf just isn’t ripe for much development early next week and the system models are keying in on will start as an area of mid-level spin, which means if it develops, it would take some work for the spin to work its way down to the surface. This less conventional top-down process presents a higher hurdle to clear than traditional bottom-up development (circulations that start at the surface and build as thunderstorms organize over warm water). The mid-level disturbance will also be starting at the base of a fast-moving jet stream dip which won’t be doing it any favors from a development perspective.
All-in-all this isn’t an area where we should expect much development. Ensembles yesterday suggested development odds in the 10-20% range, which today have largely fallen to below 10%.
Given the near-record warmth over the northeastern Gulf and the positioning of the disturbance close to land, we’ll of course watch the trends (especially for the possibility of enhanced rainfall from mainly non-tropical processes later next week), but for now it’s not anything to worry about.
Otherwise, boatloads of wind shear will keep the deep tropics quiet for the foreseeable future.
Thank you for this encouraging post!
I'll take boatloads of wind shear!
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