Supercane

My Atlantic hurricane season forecast model predicts an ACE of around 188 (90% confidence it will be between 141-235). Notably, last year's forecast of 152 was very close to the observed 162, and much closer than what was forecast by CSU (230) and TSR (240) at the same lead time. The correlation is robust going back to 1975: Perhaps the more interesting question is where will the storms go? Obviously this is much trickier to answer, but based on how ENSO has evolved over the past 16 months, the best analogs are 1967, 1971, 1981, 1984, 1996, 1999, 2006, 2011, and 2017. As seen below, there are some trends in the tracks of all tropical storms and hurricanes in these years: Therefore, I would estimate an above-normal hurricane risk for the US East Coast, Antilles, and Western Basin, and slightly below-normal risk for the North Gulf Coast. To emphasize, this is just a general risk assessment and by no means rules out or forebodes a hurricane impact in any part of the basin.

Bumping, as this ended up being quite accurate. The season's total ACE has ended up around 162. While active, it was far less active than the 230-240 ACE that was forecast by CSU and TSR. Ultimately, what is most important about a season is the impact, and on that metric 2024 ranks high. Obviously, total activity =/= impact, so whether or not landfall probabilities can be assessed on a seasonal timescale remains to be seen.

Above average, but below 200 ACE.

The retrospectives will be interesting. In defense of CSU and the other agencies, if I had released a seasonal forecast in April or May, I would have likely predicted a very hyperactive season based on how the SSTA pattern was at the time (and also knowing the El Nino was dissipating). However, my ACE forecast model (which predicted an ACE of "only" 154 this year) was purposefully released in the first week of July, because often it's not until June that the contours of a season become apparent. This year is a good example of that, having a very favorable SSTA pattern in the Spring which was significantly disrupted by a +NAO in June. A much more dramatic flop occurred in 2013, and the opposite trend occurred in 2004. Also, the evolution of ENSO tends to be more clear by June and after the Spring barrier. That said, CSU and TSR both released forecasts in early July and still called for an ACE of 230 and 240, respectively, so their methodologies obviously differ. It's far too early to make any definitive claims about how this season will progress or grade how anyone performed, but I'm enjoying the discussion about what is causing this long lull. Trying to understand unexpected events like this are how the science of forecasting is improved.

As Windspeed alluded to in the post above, the NAO has been mostly positive since mid-June. The impact of this can be seen in the SSTA pattern, with the warmest SSTAs concentrated in the subtropics between Newfoundland and the Azores, and cooler SSTAs along the Canary current and in the far north Atlantic. This is not exactly a classic +AMO pattern and began to take shape in June, concurrent with the NAO flipping positive: I still fully expect activity to pick up in September and October and for the season to finish above the long-term average. But the signs in June began pointing toward a more modest season (rather than one of the most active on record), and the ongoing lull reinforces that likelihood.

Take this as you will, but I have been working on a model to predict Atlantic ACE, using data as far back as 1975, and for the 2024 season it is forecasting an ACE of 152 (90% chance it will be between 102-202). Given the action so far, I would assume the season ends up on the higher end of this range, but it is an underwhelming projection compared to others. A key reason for this is that the Atlantic SST pattern has become a bit less favorable during the past month. Below is the plot that shows how the model would have verified in previous years (2022 and 2023 outputs were made in real time).

Beryl is also the first Cat 4 in the tropical Atlantic (east of the Caribbean) in June OR July. Previous earliest was Allen, which obtained Cat 4 status on August 4, 1980.

Yeah the usual NW trend really screwed us over. The HRRR and NAM are interesting enough to keep watching in the very slim chance this overperforms -- but no reason to expect more than an inch of snow (and extra sleet) in the southern half of Wake given the issues you outlined, imo.

I'm ashamed to admit it but the latest HRRR and NAM have sucked me back into this. We can still do it!

I wouldn't necessarily say our climo has changed. We went through terrible snow droughts in 1990-1995, 1997-1999, and 2005-2008. We're just not very good at getting snow. Of course I have hit the bottle tonight to celebrate (read: forget) this event so perhaps I missed your sarcasm in that statement.

And always go with the warmest model. I've been pretty bearish on this storm for a while but still expected a couple inches of snow (or at least hoped for it). Now I'm not sure even that is doable, at least in and south of Cary/Raleigh. We never learn.

Always, always fear the NW trend, even in the last 24 hours. 3 days out I want the jackpot in Wilmington.

The NAM bothers me. But if I had to pick 1 model to not be on my side, it'd be the NAM.