There is a rather new continuous challenge to forecasters, and Meteorologists. The internet storm hype. It's something that seems to be almost getting worse in my opinion. How many times this winter have you heard about a "big storm" heading our way next week? I think I'm asked that question every 3 days. "What's the deal with the big storm I'm hearing about?" I just shake my head.
On January 25th, I was on Facebook and was floored, when I saw a "weather page" post about a "crippling storm" for February 4-9th. At that time, we're looking at something that's about 2 weeks away. I was appalled that someone would post something with such a lack of knowledge of how people interpret that.
First, let me say that forecasting has come a long way over the years. It's not perfect, and in my mind it never will be. Especially in an area like the Valley, that in itself presents it's own challenges. Weather forecasts are at their highest accuracy within 2-4 days. At 6 to 7 days, it becomes more of a, yes it's going to likely be warmer, or cooler, or I'm keeping an eye on a possible storm. There's a lot of changes that will likely be made.
Although many forecast models give guidance for 10 days, that's simply it, they are guidance. Just because someone has learned to read what a forecast map is depicting, it doesn't mean that's a forecast. There's much more that goes into a forecast than just what a model map is predicting.
In the age of Facebook where any weather enthusiast can start a page and post "snow storm totals" and "upcoming storm next week", that's presented many new challenges to broadcasters. I get that weather is interesting and people want to share. But when there are pages that post "snow potential of a 8"-12" in 10 days", that's misleading.
In my opinion I think it's holding back some of the advances in accurate forecasting, because it's leading to conflicting and inaccurate information.
So have you heard about a BIG STORM for this weekend?
Well, there IS a system that we're watching.
Take a look at what two of the forecast models suggested on Sunday.
Now the information came out last Sunday, but it's suggesting a storm for sometime around the 9th, this upcoming weekend.
That blue line is what's called the rain/snow line.
Anything to the left would indicate snow. Looks like a massive storm doesn't it? All of those colors are heavier precipitation. But, that "massive storm" is 7 days away. A lot can happen in 7 days.
Now take a look at the latest guidance from this afternoon.
That rain/snow line is well south of the area, meaning it's going to be cold.
But where's our massive storm?
I posted the same forecast times to give perspective.
This is why you should not believe a "big storm" that's more than several days out.
There are too many variables that can change and a lot of that relies on what happened today, and what happens tomorrow, etc.
As Meteorologists we create forecasts based on current conditions, and what we think, based on guidance, the area, and dynamics what would most likely happen.
Now I'm not saying we are not expecting any snow this weekend. In fact we are looking at some LIGHT snow Saturday afternooon, and Saturday night. George Hirschmann just said it best. "We are looking for a little snow this weekend but I'm not looking for an event."
Could that change, yes. We are tracking it but that's what we do as forecasters. We track the slight changes over time to give you the best forecast we can.
One other side note is that when models show snow, for example this is showing 1"-2" for most of the area on a certain day.
The models are based on a 10:1 snow/liquid ratio.
Meaning that for every 1" of liquid there will be about 10" of snow.
However snow doesn't always fall like that.
Depending on temperatures, that ratio will change.
Just be cautious when reading facebook posts, or weather blogs that post storm information that's more than 5 days out. Don't buy into the hype, and follow the trend in the forecast over time.