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Comment by photochemsyn | Hacker News Reader

Interesting capabilities but why don't they report the capabilities of the model beyond a 24-hour cutoff? What do their 5-day forecasts look like?

[edit] Modern numerical prediction models are pretty good in the five-day range (~90%), I'm guessing the deep learning models diverge rapidly in comparison (though perhaps they're better in the sub-24 hour range). Both approaches benefit from more extensive data collection systems as inputs. See (full text):

"Advances in weather prediction" Alley et. al Science 2019

https://par.nsf.gov/servlets/purl/10109891

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I get the impression this model is meant for very localized, short term prediction. Like whether or not its going to be raining in your neighborhood in the next hour.

It looks to me like it's "upscaling" ENS data to high resolution. Global general circulation models work with somewhat low-resolution data about terrain, and this model has found a function mapping the low-resolution weather predictions back to a prediction on high-resolution terrain.

(ed.: true also, but to a lesser extent, for "mesoscale" models (e.g. of just North America with boundary conditions to a global model))

If it did learn longer-range predictions (or the next model does?), I would hazard the model had achieved speedup by internalising the patterns of certain large-scale weather connections, e.g. the jet streams, Walker circulation, ENSO, Gulf stream... which I think will be fine for 99% of cases, the 1% being if these established patterns break somehow. ("freak weather")

At that point you would have to return to a general circulation model. When you take away the long-lived circulatory features that are familiar to us, and that are particular to Earth, predicting the weather is "just" fluid dynamics.

These are both just wild guesses, though

Does anyone's 5 day forecast look good?

5 day is closed to wild ass guess in my area. Mountains complicate everything

Anything over 24 hours is pretty much always very wrong in the mid Atlantic region.

How often do you need weather services in the middle of the Atlantic though? Seems like a pretty niche use case, except for the various islands there.

Edit: I thought something was sketchy and rightly so, after searching for "Mid Atlantic Region" I learned that it's actually a region in the north-east US, not "the middle of the Atlantic". Well, learned something new today :)

Mid Atlantic = south of New England north of Virginia (more or less), not middle of the Atlantic Ocean.

Not to be confused with a mid-Atlantic accent, which is possibly what you might get around the middle of the Atlantic if your interpolated a couple of specific local accents between the UK and the US

The Mid-Atlantic [coast] is part of the US east coast around NY, NJ, Pennsylvania, etc rather than literally the middle of the Atlantic Ocean. It's a fairly important region considering how much of the US and global economy reside there.

As someone who both lives in the mid-atlantic and regularly has to plan around the weather, I can assure you that you simply have a confirmation bias. Our forecasts are actually pretty good, even for ones 7 days out.

Where people tend to get thrown is micro-storms during the summer months. They are basically impossible to predict accurately, at best it's just known that a random assortment of towns in a given area will received heavy rain for a short time. Being able to read radar is the best way to deal with this, but it's very short term only (15min to 1 hr).

Reading radar is even harder because you need a 3D view of the atmosphere to understand why storms are coming seemingly out of thin air. This is especially a problem near rivers. We only get a 2D doppler slice.

You just have to look at the 2D slice and see if a storm pocket is headed your way. That's the best its gonna get for a layman.

yes? https://charts.ecmwf.int/products/plwww_m_hr_ccaf_adrian_ts?...

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