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Comment by hackitup7 | Hacker News Reader

I've been really impressed at how much better weather forecasting has become already. I remember weather forecasts feeling like a total crapshoot as recently as 15 years ago or so.

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It still is. I farm outside of my day job and trying to schedule time to do things like cut hay is sort of a crapshoot. Hay needs a 3-4 day window to dry, rake and roll. This year I got rained on at least twice on days where the NWS showed clear and sunny for 3 days on the spot forecast. 20% or 50% chance of rain is almost useless knowledge. We went for weeks with a 20% chance and it never rained. We still got everything done but it sticks out a lot when you are watching it closely.

If you live in an area with "summer storms" it's basically impossible to forecast anything more than a general area (usually thousands of square miles) that they will appear in.

Its like a shotgun shooting a wall. You can pretty accurately predict the area of the shot, but its incredibly hard to place where exactly each shot in that area will land.

I do live in such an area and we end up just taking the risk a lot of the time. Most of the time it is fine. Sometimes disaster. It is a bit frustrating.

Yup, I had the same issue. Showed 4 days of clear 80-90 degree weather. Twice in that timeframe it rained (!1 inch each time), ruined the cut.

Well it's actually not a 20% or 50% chance of rain. It's that it will definitely rain but only for 20-50% of the projected area forecasted

This is exactly wrong.

> The "Probability of Precipitation" (PoP) simply describes the probability that the forecast grid/point in question will receive at least 0.01" of rain.

[1] https://www.weather.gov/ffc/pop

It is worth noting the estimate is an areal average.

Isn't that highly subjective to where you live? Because I moved to Scandinavia and the forecast here is so incredibly bad, compared to central europe.

Central europe (minus the alps) is way easier to predict. You can just look at the clouds on a satelite and see how they move, usually west to east, and then extrapolate linearily.

All the fjords and mountains and lakes in norway really make it hard, to precicesly model it. And I think they strongly and chaotically influence the weather in sweden as well.

Also, there are way more people living in central europe, so probably more effort is spend on them.

The accuracy is definitely location dependent, but I anecdotally agree with the GP that the accuracy has improved substantially, at least for the UK where I am.

Ten years ago, the weather forecast was so unreliable that I just assumed anything could happen on a given day, no matter the season. Frequently it would be unable to even tell you whether it was currently raining, and my heuristic for next day forecast instead was to just assume the weather would be the same as today.

Nowadays I find the next day forecasts are nearly always accurate and hourly precipitation forecasts are good enough that I can plan my cycles and walks around them.

Yes, driven by local data collection. More tightly packed ground stations and the availability of atmospheric measurement at various altitudes will improve accuracy.

Also, the weather is just a lot more predictable in some areas than others.

I think it's mostly this. If you look at a weather radar map, sometimes you see a speckled pattern of rain where there is heavy rain in places, and 100 yards away there is no rain at all. No way you can predict that multiple days out.

I feel this living in the path of moisture coming from the Gulf of Mexico. My phone has gotten good at letting me know when the rain will start and stop to within a few minutes, but whatever data source Apple uses still struggles with near-term prediction (day+) in the summer when there are random popup storms all the time.

This. Just some days ago I had a conversation with meteorologist who said exactly this - the weather has never been easy to predict in northen Europe and it has become even less predictable with climate change and global warming.

Moving from Phoenix to Austin was a bit of a shock. Weather prediction in Phoenix is essentially perfect. In Austin the forecast seems much less accurate.

This is partly due to less satellite coverage, something this project is trying to fix: https://www.esa.int/Applications/Observing_the_Earth/Meteoro...

If you live in an area with a lot of microclimates within one city, weather forecasting is honestly no better than astrology.

I was just telling my wife this after looking up the "no rain" weather report and getting absolutely showered 5 minutes later in an hour-long rain storm. Weather reports suck so much.

Weird (very local in particular) stuff still happens and tropical weather tracks, for example, can still be pretty unpredictable. But, living in Massachusetts, I still remember how the Blizzard of '78 basically caught everyone by total surprise and left hundreds/thousands(?) of people stranded at work and on highways. Never say never, but it's pretty unlikely you'd see that level of surprise today.

(A friend of mine who moved to the Boston area about ten years after the event once told me that she had never seen a northern city in which so many people headed home from work if they saw so much as a snowflake.)

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