[GeoffKnauth]

From talking with meteorologists, it seems forecasting actual rain is not very hard if you have enough current data on the state of the atmosphere. What can be difficult is mistiness that is just on the borderline between falling droplets and moisture just hanging in the air. Differences can be extremely local in nature. [I'm not a meteorologist, I program computers, but I'm a pilot so I have a pilot's appreciation of and contact with weather.]

[roter]

Or even the proportion and impact of ice v. water droplets. The modelling of this in a warming world is making the latest global climate models used in the upcoming IPCC AR6 show a higher equilibrium climate sensitivity than the previous edition [0].

[0] http://www.realclimate.org/index.php/archives/2020/06/sensit...

[brootstrap]

Hi geoff - seems like you are pretty knowledgeable here. I have to disagree with "seems forecasting actual rain is not very hard if you have enough current data on the state of the atmosphere" ... Who told you that? accuweather meteologists?

Rain is not easy predict, especially long in advance. Just taking things with a grain of salt here. If you truly believe that forecasting actual rain is not very hard, please start a new weather forecasting company and give it all you got! However i'll tell you, it's not that easy. Just because a computer model 'runs' does not mean it correctly modeled the atmosphere. All models are imperfect bud and those imperfections get amplified by 10x when trying to simulate earth+atmosphere systems

[GeoffKnauth]

No, I'm not especially knowledgeable, not more than others here. As a pilot, I have 42 years of experience flying through weather and helping get the word out w/r/t hurricanes, e.g., relaying info via ham radio in the West Indies from relays in Florida before getting hit by the storms, back in the 1970s when that was the way, so I have long interest in and appreciation of weather. But I do also have appreciation for my colleagues and their meteorological expertise. They have something called MinuteCast which in my experience has been very accurate in telling me when precipitation will begin or end (except when it is misty). Regarding my "forecasting actual rain is not very hard" remark, you are right that a "long in advance" forecast is hard, but I was talking about the short term. Specifically, a commenter had wanted to know if it was going to rain before going out to exercise, and for that example, I meant a forecast of precipitation was easy.