How far out is too far out?

[Shane Adams]

IMO the obvious answer is there is no definitive answer. Meteorology is an inexact science to begin with. Seems the deciding factors on when is a good time to start getting serious would be personal, i.e. how far away you are from target, whether you're interested in long range forecasting or not, what time of year it is, etc etc.

My answer? 24hrs before the event. It's going to change constantly anyway, and because I have no interest in forecasting (beyond finding my target), there's no need to get worked up 3-4 days out. But I still do anyway sometimes.

 

[Stan Rose]

Dont have too much to add; as Jim L. said consistency is one good thing to look for, also the particular pattern that is forecast: a giant death ridge is more likely to be a stable solution than trying to pin down a succession of progressive waves.
One thing to be very aware of though, is that as some have mentioned, even if you are able to accurately predict the pattern that may be useless toward pinning down the details: case in point, the blizzard that hit my area last couple days. The h5 pattern was accurately progged by the ECMWF (not the gfs tho) over a week ago, but 24 hours before the event, the NAM was forecasting significant snow on tuesday, not much on wednesday. We were dry slotted on tue and got next to nothing, Wed was the blizzard. If you can't trust a 24 h. prog, be wary of your 7 day forecasts!

 

[Brian Stertz]

Trends and evolution of the upper jet structures is what I look for the most when peeking way out into forecast space. Sometimes this gets hampered by the limited panels on the Euro and Canadian models that forecast out to 168 hrs. or less. GFS works for latching on to trends, but often seems to like to cutoff stuff at unusual times, and then the next run it shows an awesome progressive trough. As Shane said this is truly an inexact science. I am more often than not quite guilty of being too optimistic with things, but I've learned to watch ensembles closer and to fall back on the others (Euro & Canadian) to see if those patterns are also being signaled. It's all a matter of planning more than anything in my use of these extended models. Last spring was prime example.