The 360 Hour From Now Hurricane That Won’t Happen

Here’s the good news. 360 hours out, especially in the summer, we have almost no skill at all!

Have you seen the 360 hour forecast from the 18z GFS? Don’t worry. I looked for you!

The GFS (Global Forecast System) is a dynamic atmospheric computer model. It’s one tool in forecasting the weather.

The +360h iteration (valid August 25, 2011 at 1:00 PM) puts some sort of hurricanish storm just south of Long Island. Ominous is a good word to describe what the map portrays.

Here’s the good news. 360 hours out, especially in the summer, we have almost no skill at all! Saying its late August is probably a more convincing argument for a nearby hurricane than anything the GFS outputs.

Every time I see one of these systems (nearly guaranteed not to be on the next model run) I ask myself the same thing: Why even bother going out that far?

I don’t think there’s a good answer.

13 thoughts on “The 360 Hour From Now Hurricane That Won’t Happen”

  1. Hi Geoff, very interesting, didn’t even know they predicted that far out. Is it ever right? Like did they predict a Rita or Charlie in 04? Just curious

    1. It might be right on some features some times, but these are complex scenarios. I’d be happy if we were always well informed for day 3.

  2. There is only one good reason for publishing these models so far in advance it gives you something to talk about on your blog. It would be great if we could all look at a model and know what the weather would be like on our vacation 6 months in advance but we both know that’s unlikely to happen any time soon. If however this model does turn out to be right there will be some egg on face for you though, A certain weather forecaster in the UK told his viewers there was nothing to worry about when 100mph storm winds rushed through the south of England…..
    Still its 15 days away and chances are it will be a nice day with a chance of thunderstorms as i’ve noticed the pattern is for weather around these parts during the summer months…

    1. I’ll quickly admit I’m wrong if it looks like that’s the case. It’s a forecast, not a child. I change when I have to.

  3. I always KNEW, you weather-people had a rackett going! LOL!! Seriously, though, how good a tool is this?? Are the GOES satelites still operating? Just curious!

  4. While this is just an image, we haven’t had a major hurricane in a long time. Perhaps you should convey some hurricane saftey. The issue i’ve always had with a hurricane is “Where do i go”. I95 runs East and west in connecticut, so i have to pick the lesser of two evils to get inland. What is does an acceptible storm kit contain?

  5. Adam… Not to overstep Geoff, but check out and if a storm approaches such as a hurricane, pay attention to local officials. Each town has an Emergency Management Director and it is their job to determine evacuations and communicate shelters, etc. If you are interested in getting specific information before hand, contact your town’s EMD and they can answer your questions. Your town hall should be able to give you contact information. Hope this helps.

  6. I was wondering, I know storms “cook up” fast sometimes sort of “out of nowhere” like Cindy did. Could this sort of thing be why this 360 hour “forcast”? I know we always look to African coast and the “waves” that come off but is this also possible? The weather lately is so weird it makes me wonder “what next”?

  7. Geoff, I’m wondering if the recent hot water has caused warmer than normal temps in the Atlantic? And it so, do increased ocean temperatures increase the chances of a hurricane coming up the coast?

  8. Looking back on this 16 days later, it’s kind of funny how the model was right. A little off, but close enough! Well, better get back to preparing for “The Hurricane That Looms in the Distance”! Be safe everyone!

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