So Cal weather experts - what does 40% chance of rain REALLY mean?

VandVsmama

DIS Veteran
Joined
Mar 28, 2011
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Hi everyone!

We've leaving for our DL trip in just a few days! The updated weather forecast on Weather.com says that there is a 40% chance of morning rain on Sunday 10/4. I live in Tucson and it's been long enough since I lived in Southern California that, honestly, I've forgotten what the CA weather patterns are when it comes to rain.

You see...out here in the wild wild west of Arizona, a 40% chance of rain still doesn't mean much. It could mean that it'll rain down the street, but it could be bone dry at your house.

I'm trying to figure out if this means that we should bring umbrellas with us or not. I'm going to bring some cheap Dollar Tree rain ponchos for sure, but what does 40% chance of rain really mean at this time of year? Should I expect a light rain or a monsoon downpour?
 
It means that there is a 40% chance that it will rain.

You're going to have to find a more detailed weather forecast that breaks down the chance per hour and the expected amount of rainfall to get more details. There's no predictable rain pattern for days when it rains.
 
I'm looking at Accuweather right now and it says 55% chance of a passing shower in the morning. That doesn't really sound like anything you'd need an umbrella for, but maybe it will firm up later in the week. We'll be there too, so a little misting would be nice. It's still supposed to be 87.
 

I just looked at the National Weather Service's website (forecast.weather.gov) and entered in Disneyland's zip code and it's showing a forecast of:

"Sunday
A slight chance of showers. Cloudy through mid morning, then gradual clearing, with a high near 79.
Sunday Night
A slight chance of showers. Increasing clouds, with a low around 69.
Monday
Mostly cloudy, then gradually becoming sunny, with a high near 82."

A high of 79 would be perfect! I think that I'll pack my kids' umbrellas and we'll decide Sunday morning when we wake up whether or not to bring them into the parks with us.
 
It probably won't rain at all. But the weather can change quickly so there's no real way of knowing
 
I don't usually pay too much attention to anything under a 50% chance of rain. Under 50% means it's not likely to rain, in my observation. If we get to a 50%-60%-ish chance of rain, I keep checking the skies to see if I need to bother with the umbrella because it's a strong enough chance where that something could happen and I don't want to be caught off guard. A 70% chance and above -- I usually consider it to mean that it is pretty certain to rain at some point, even if only for a short while.

At this time of year any kind of rain would probably not be the heavy, non-stop, torrential kind. It would be more along the lines of rain that people can get around in fairly easily. I say that, even though I remember being at DLR in September 2007 when it was pouring heavy, long-lasting, messy rain at random intervals. That's not the norm for September or October, though.

Once we get into December and begin to inch ever closer to the beginning of the El Nino-related rain, that will be a whole different ballgame, of course.
 
If you look at Weather Underground, the majority of rain is suppose to fall between 3AM and 9AM. So, I'm thinking it probably won't have much impact. Now, the trick is it could be a sprinkle of rain at 3AM and nothing otherwise, or it could be pouring for those 6 hours. It depends on how the showers hit the area. We've had some weird weather this year, so if you're going to be there that morning (we will be), bring portable ponchos (you can get cheap ones at walmart), but keep in mind that most of the day will probably be okay.
 
The weather report is looking better for Oct 4th! Looks like 20-30% chance of possible showers in the early morning. Yeah! And the highs are lower than they were predicted to be. Hopefully making for a more pleasant visit.
 
Once we get into December and begin to inch ever closer to the beginning of the El Nino-related rain, that will be a whole different ballgame, of course
SOrry to thread jack, but the el nino related weather isn't supposed to be an issue until December or later? If so, that's good news for our November trip! The last I'd read, they were concerned about it for November too, I think..but that was a while ago
 
SOrry to thread jack, but the el nino related weather isn't supposed to be an issue until December or later? If so, that's good news for our November trip! The last I'd read, they were concerned about it for November too, I think..but that was a while ago

Honestly, it's hard to predict. The bulk in the past has hit in December and January. That doesn't mean there won't be rain in November, just that it probably won't be as bad and for multiple days at a time.
 
Honestly, it's hard to predict. The bulk in the past has hit in December and January. That doesn't mean there won't be rain in November, just that it probably won't be as bad and for multiple days at a time.

The bolded is what I was concerned about :) I certainly expect weather in November (I grew up in NY, so snow was not unusual in November), but I was hoping to avoid constant/multiple days of rain. We'll be prepared for it regardless, though...thanks :)
 
I'm so hoping the El Niño weather pattern actually delivers this winter. It may not be fun to be in torrential rain in the parks, and I'm sure flooding will be a problem, but we need to get our water table back where it should be.

VandVsmama, it looks like your weather this trip will be lovely. Maybe light morning showers and then clearing. Have a great time!
 
I certainly know CA needs rain, so I do hope that you all get what you need this winter! And I hope that it comes without too much damage in the process (flooding, mudslides, etc).
 
I certainly know CA needs rain, so I do hope that you all get what you need this winter! And I hope that it comes without too much damage in the process (flooding, mudslides, etc).
I hope your trip will be amazing! I've always wanted to go in November, but it hasn't worked out with my schedule. I hope I didn't sound like I thought you were insensitive to our water needs. Everyone wants great weather for their Disney trips...I know I do!
 
SOrry to thread jack, but the el nino related weather isn't supposed to be an issue until December or later? If so, that's good news for our November trip! The last I'd read, they were concerned about it for November too, I think..but that was a while ago

Originally it was said that the El Nino rain would arrive in the Fall, and then it was supposed to reach a peak around late Fall/early Winter. At that time I was thinking, "Hmmm... it's more likely to pummel us from December into Spring of next year." (I remember some very, very rainy times between January and April.) Now, of course, the estimates are that the El Nino rain storms will begin at the end of the year and carry into Spring. And there is even still a small chance that it will fizzle a bit and not be as wet a winter as predicted, or not be as intense.

Either way, I don't expect that the bulk of the El Nino mess will hit in November, if any of it sneaks in at all. In fact, if anything, I tend to think that next November (in 2016) might carry some of the straggler El Nino rain, but that this coming November will likely just be a regular November (and a regular October).


I certainly know CA needs rain, so I do hope that you all get what you need this winter! And I hope that it comes without too much damage in the process (flooding, mudslides, etc).

The rain has to mainly fall up north and pile onto the snowpack in order to help the drought statewide, and if the worst of it falls in SoCal then it won't help us too much. But what a lot of El Nino rain does bring to the state is a lot of mess and a lot of problems -- there's no way it won't cause trouble, because this is not a state that is prepared for it. When it rains for even one day -- like it did recently -- all hell breaks loose. Just imagine what can happen if a lot of non-stop heavy rain falls for days and weeks on end (which is what has happened during previous El Nino years). It can be mayhem! What would be ideal is a lot of rain that then stops for a while, giving the ground a chance to dry out, then another round of rain, then another dry out period, etc. Unfortunately, what happens too often with these pesky El Ninos is that there is not enough of a break between storms -- if any -- and the ground becomes saturated.
 
The weather report is looking better for Oct 4th! Looks like 20-30% chance of possible showers in the early morning. Yeah! And the highs are lower than they were predicted to be. Hopefully making for a more pleasant visit.

You know, it's weird. It has still been hot -- upper 80s/low 90s -- but the humidity has eased up a bit, and there is a certain 'edge' that the heat had a few weeks ago that seems to be missing now. I can't explain it but it's as if it is a milder, not-as-harsh, heat. A couple of weeks ago a so-called "breeze" in my area of town felt like a gust of sauna air, or steam from a cauldron hitting me in the face. Now.. a breeze is slowly starting to feel like an actual breeze again. I guess that Fall is finally trying to push Summer out of the way, thankfully! :banana:

It will still feel hotter in Disneyland, but at least it's not quite as uncomfortable as it has been just recently.
 
You know, it's weird. It has still been hot -- upper 80s/low 90s -- but the humidity has eased up a bit, and there is a certain 'edge' that the heat had a few weeks ago that seems to be missing now. I can't explain it but it's as if it is a milder, not-as-harsh, heat. A couple of weeks ago a so-called "breeze" in my area of town felt like a gust of sauna air, or steam from a cauldron hitting me in the face. Now.. a breeze is slowly starting to feel like an actual breeze again. I guess that Fall is finally trying to push Summer out of the way, thankfully! :banana:

It will still feel hotter in Disneyland, but at least it's not quite as uncomfortable as it has been just recently.

I know what you mean! I've noticed the exact same thing here in Arizona! At lunch time today, it was very pleasant and you could eat outside if you wanted to and not sweat your brains out. I'm looking forward to our trip because temps on Sunday in Anaheim are supposed to be high of 72, on Monday a high of 75, and on Tuesday, a high of 79. On Sunday, I'm definitely going to need a sweatshirt because I'm a delicate desert flower and anything below 75 is frigid. LOL!
 



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