Haven't updated in ~ 10 days. Currently at 61 ACE per Colostate.

For my own trivial climatological model I get a couple estimates starting from today -- point wise ACE ~87 +- 23 (weighting season analogs (exponentially) by ACE at this point of time), and a much simpler point estimate of ~126 conditionalizing on seasons with >= current ACE ). If you assume no named storms for rest of September only the first point estimates drops a tiny bit to 84.

Weathertiger has the 50% value at 128 as of yesterday.

Climatologically (1990-2023) there is upwards of about 70% chance there should be a storm present sometime in the remaining part of September.

For next genesis, TWO puts a TC in the Caribbean/GoM at 40% for next 7 days.

The Helene market (https://manifold.markets/SaviorofPlant/when-will-a-tropical-or-subtropical-8b0q8g76za) is sitting right now at 55% for a TC by the 26th (this may be generous). Speculatively, ACE from the deterministic CMC, GFS 12Z looks to add about 5 to 10 ACE for the Caribbean/GoM disturbance if it develops. High potential heat content right now in the area if develops east of the Yucatan and tracks north:

Above-normal looks too cheap... so I'm betting that up a bit.

A season ACE where we end up < 73 I'd still assign as a very unlikely (maybe ~1%) given how much time is left, so I'm not willing to hedge above the current value of 4%. I've put in a limit order for the rest of September though for 1% but I doubt it will ever reach there given there is not enough bettors.

@parhizj The next week or two will be important in determining whether we end up near-normal or above-normal, since we have the MJO amplifying Atlantic activity.

We've bent the curve and reached the climatological mean for 1991-2020...

Francine looks to add ~ a meager 5 ACE.

TWO has next TC 70% in 7 days (I put a TS well below that though around 50%). In short my ACE forecast has dropped a bit into the normal range...

Colorado State University released a discussion of the recent inactivity: https://tropical.colostate.edu/Forecast/2024_0903_seasondiscussion.pdf

Quote that stuck out to me the most: "Only one other time in the satellite era has the Atlantic not produced any named storms between 13 August and 3 September. That other year was 1968."

There's no forecast update, but they still expect an above average season

@SaviorofPlant "So at this point, while it would be highly unlikely for CSU’s seasonal hurricane forecasts to exactly verify, there is still potential that a hyperactive season could be reached."

I interpret that for this market this as sounding like 'Above normal' as expected (slightly?) more so than hyperactive.

Figure 29 I found useful relative to Figure 15.. I wish they had a version of Figure 15 climatologically to see whether instability will return to at least 2023 levels by end of September....

The current wind shear and forecasts means we likely won't get a STS from that low in that NW Atlantic for the Francine market...

@parhizj Another quote I found valuable was this:

"One of the big issues plaguing the Atlantic has been the monsoon trough being so far

north that the easterly waves emerging from Africa are coming off at too far north of a

latitude to reach hurricane-conducive conditions. However, as the hurricane season

progresses, the climatological African Intertropical Front shifts back southward in

September (Figure 27).

Suggests we should still expect high activity in mid-September into early October, which is consistent with the 10-day model forecasts. Given we're already at 40 ACE, we don't need that much additional activity to get into the above-normal range.

I came across a forecaster that does project real time ACE that bettors might find useful (albeit slightly different buckets for this market)

https://weathertiger.substack.com/p/real-time-2024-atlantic-hurricane

The wide ranges for ACE seems very much reasonable at this point in time.

If anyone else has found something similar feel free to share if you wish.

@parhizj Projected ACE is plummeting with each passing day

@SaviorofPlant That weather tiger still has > 165 Ace at 62% .... I

From my notebook: Aanalogs by cutoff:

Top 10 weights (sorted by weight)
----------------------------------------
Rank  |  Year  |  Weight  |  Season ACE
----------------------------------------
   1  |  1998  |  0.189   |  181.16
   2  |  2023  |  0.186   |  146.79
   3  |  2012  |  0.140   |  132.63
   4  |  1979  |  0.067   |  92.92
   5  |  2007  |  0.057   |  73.89
   6  |  2010  |  0.053   |  165.48
   7  |  2021  |  0.052   |  145.56
   8  |  1999  |  0.051   |  176.53
   9  |  1989  |  0.028   |  134.84
  10  |  2003  |  0.024   |  176.28

I haven't put enough effort into my model as last year it was a bust.. This year the RMSE is very high early on... (+-50 ACE doesn't inspire any confidence...):

RMSE tuning: 34.14
RMSE validation: 53.24
Difference of RMSE(tuning) - RMSE(validation): 19.10

Last week:

Today (not much change, just a bit tighter CDF):

@parhizj After getting killed on the Francine market I have emotionally decided that the season is going to be much less active than expected. Time will tell if this is profitable.

I do want to note that this type of inactivity is extremely anomalous - even El Nino years usually manage to get a few storms in the first half of September. Like looking at your analogs, 1998 had two Cat 2s active at this point, 2023 had just had two majors and Lee was about to form, and 2012 had four hurricanes in late August into early September. If activity suddenly kicks up then a hyperactive season might still be possible, but I'm increasingly skeptical.

Not likely relevant, but @SaviorofPlant, are you doing (lower, upper] or [lower, upper)? It's not clear from the multi.

I'll resolve 50% each if it's exactly on the boundary

17.1 as of this morning, vs an average of 2.5 at this point in the season:

https://tropical.atmos.colostate.edu/Realtime/