Will a tropical or subtropical storm form in the Atlantic basin before the start of the official hurricane season?
Jun 2

The hurricane season stretches from June 1st to November 30th. However, in recent years there have been named storms forming in April, May, and even January. 2015, 2016, 2017, 2018, 2019, 2020, 2021, and 2023 all had named storms form before the official start of the hurricane season.

This market resolves YES if a tropical or subtropical storm forms before June 1st in the local time in the location where it forms. A storm in the part of the Atlantic in the southern hemisphere would count, but tropical activity there is exceedingly rare.

See also my El Nino / La Nina market for hurricane season: https://manifold.markets/SaviorofPlant/will-it-be-el-nino-la-nina-or-neith. El Niño tends to suppress Atlantic tropical cyclone activity, while La Niña tends to enhance it.

Get Ṁ600 play money
Sort by:

I took out a big No position. Highly unlikely a storm will reach TS speed / be named in the next 3 days with nothing on the NHC outlook.

Not sure why this is still trading at 15%. Should be 1% imo. Biggest Yes holder is a bot🤔

Placed a YES limit order for the next ~12 hours at 1%:

ECMWF 12Z cyclone product predicts some type of disturbance (but this is not a tropical storm though) -- is this what YES holders are holding on to? FSU experimental ( https://moe.met.fsu.edu/modelgen/summary168al.php ) and NOAA's outlook https://www.nhc.noaa.gov/gtwo.php ) has nothing.

My own analysis has GFS 12Z (but not ECM 12Z) showing a possible TD developing there (but not becoming a short-lived tropical storm until after June starts -- for the last couple days I only have one NAV and one GFS run showing some type of disturbance developing, so I estimate it is still very low probability (<1% of this resolving YES, but the outside range is something like 0-8%.)

@parhizj May storms are often poorly modeled, so the chance might be higher than 1% - still very low though given there's just 3 days left

@parhizj I put my yes because apparently these two storms are not enough to be classified as subtropical storms? (South and north Atlantic respectively) They seem to meet the wind threshold. I must be missing some other important features.

That being said, I'm holding out on the 3 tropical waves at this point.

@Shifbru South Atlantic subtropical stuff is never classified, since it's such an inactive basin.

The North Atlantic system is over very low SSTs:

I believe there have been exceptions, but temperatures that low are usually not supportive of subtropical development and almost every low you find in that area is non-tropical.

sold Ṁ5,562 NO

@SaviorofPlant Can you please clarify precisely what resolution sources you will use?

If anyone cares, I will no longer be betting on this market.

@SaviorofPlant Thanks. Pedantic notes about resolution criteria for TC markets:

Something you might not be aware of is that different agencies have different pages depending on the quality of the information and pages also used for archives. Not all of these are updated regularly (some of them are staggered).

For instance, NHC https://www.nhc.noaa.gov/ home page is updated daily but their best tracks page ( https://www.nhc.noaa.gov/data/tcr/ ) can take months to update (for instance Hurricane Hilary (2023) in the Eastern Pacific took ~5 months after the storm for NHC's report to come out).

As per the page you listed for SATL it looks similar to the TCR page for NHC, and so I suspect that updates to it also are significantly delayed from when the storm actually took place.

In either case it is useful to specify specific pages if possible or what type of documents will be used for classification (best tracks/warnings/charts/etc).


NHC has started outlooks again (nothing in 7 day window)

More related questions