At 73hrs if there's red within say 20 miles of your path, sit on the ground. If there's yellow go around it. Not super helpful with the technology, sorry, because I, too, rode the short bus, plus it's been my experience that "weather is where you find it" when it comes to operating an airplane (that is to say: sometimes things will look peachy and suck, sometimes you'll cinch the belt down so much it hurts and...fly through a gentle drizzle). Don't mean to detract from the conversation. Definitely some interesting reading from surreal...just remember that things always look a little different when it's your dumb ass doing the penetrating.
Yeah, 20mi is the rule of thumb I've got. For example, I fire up the plane and let the box start the weather download while I'm getting ATIS, calling departure, etc. Plan was fly from AUS up to Taylor to get some gas, then go tool around.
Well, I get to the runup area and the screen refreshes and there's a nice little red pocket sitting right over Bird's Nest - directly in my path to Taylor. So I look around at the sky, and to the south it's looking better, and the Wx says that other than a little green pocket 25 mi west of Lockhart (K50R), it's pretty clear.
Tower was gracious enough to re-do my departure clearance for me, sent me on m'way.
If I hadn't had that, I likely would have blundered into that pocket - I couldn't see it. Maybe I would have once at altitude, I dunno.
When I was returning to AUS, things looked good, ATIS was fine, and as they brought me in on a left downwind I see two massive rainshafts north of the airport, little south of Georgetown, I'd say. Sure enough, there they are on the screen - pockets of green and yellow. Plenty of space for me to swing in and land, though. Learned - on that approach - just how quick you can slow a 152 down, too.
The point being - and the reason I started this thread - is that I won't always HAVE the Wx device in the airplane, or it may crap out. So I'm trying to learn about what's really up there from the pre-flight routines, and using the NEXRAD stuff from the computer is a helpful tool. I just want to learn more. I'm starting to turn kind of obsessive about weather, and sometimes it's frustrating when I don't have all the understanding that someone like Surreal does. Thus, all the questions...