http://airfactsjournal.com/2013/09/thunderstorm-flying-in-the-age-of-datalink-weather/?utm_source=airfacts&utm_medium=email

 

Datalink radar or onboard radar? XM or ADS-B? Panel mount display or iPad? The options for receiving and viewing in-flight weather have never been greater, with a proliferation of affordable and capable avionics coming on the market over the past decade. This is a great problem to have–airline pilots of 50 years ago would have killed for any of these options–but it’s still a problem. Which one is best? And what’s the right way to use each tool?

The same rules still apply.  You need to know the forecast and NOT fly if you don't need to.  XM and other internet/internet to SAT WX is still 5 minutes behind....more then that depending on the last update.  And those updates do not always happen on time and/or some data may not get downloaded. 

 

I've never flown with XM in the air but use it on the ground with Baron's Mobile Threat Net.  It all uses the same data source.  It's great for a big picture overview, but doesn't always tell me the things I need to know like SRV or BV in the tilts.  Same with VIL (hail core intensity).  It's also NOT dual pole which can come in handy for determining precip types.

 

I think it's good for a big picture type scenario, but other sources need to be used even beyond the AWC.  You need to know the convective outlooks for your areas, watch for MDs being issued (convective and winter), etc. 

 

I have a friend who does aerial storm chasing and we both GR on the ground and in the air.  I think pilots need to learn more about storm structure as well.  At least to be able to identify a severe storm versus a high based non severe storm.  Learn what an updraft column looks like, outflow boundaries (gust fronts-roll clouds), striations in the clouds (rotating storms), and wall clouds, just to name a few. 

 

Go a little further then what's in the ground school training materials about warm and cold fronts.  Remember:  Lowering bases often happen as storms gather strength and go from a more discrete form to a linear and/or MCS or MCV (land hurricane looking) system as they often do after dark.  Basically understanding what a stable storm (stratus deck) versus an unstable storm (loads of CAPE and EHI --supercellular) looks like.

 

Remember weather radar shows precip only, which doesn't mean a lot in my opinion, unless you know the characteristics of the dbz or radar return.  White returns usually indicate a strong large hail core, but you need to be able to see the VIL mode to be sure.  Not many people know what an inflow notch (hook echo) looks like in the precip mode (or base reflectivity-BR), and what tilt your radar is on so you know at what height you're looking at the storm on.  From there you'd need to be able to switch to Base Velocity (BV) and/or Storm Relative Velocity (SRV) mode to make sure you can spot a velocity couplet (i.e. tornado) and how strong and wide it is.

 

Now take all that data that you don't get while trying to fly and make a diversion or go/no go decision...LOL.  Now you see why I don't put much stock in weather radar because, it's a little too late by then. 

 

I think I may not have answered your question completely, and probably gave you other info you didn't want, but hope it helps a little bit. :Nerd:

 

 

I think I may not have answered your question completely, and probably gave you other info you didn't want, but hope it helps a little bit.

 

I found your insight and information helpful!! Thanks..............

I used XM satellite weather in the cockpit for about four years. Yes, it can be five minutes behind, but the overall picture was highly worth it, when flying cross country, out here in the mountain west. With a flight of two or three hours, it's easy to see the trend of weather patterns. It removes a lot of the unknown, as well as providing current altimeter settings, and TFR patterns while in flight. Not perfect, but beats the old methods by a long shot. Having a close to real time weather display in the cockpit, is rated as one of my must haves.

When we fly across the country XM weather is nice to have so we can make several possible routes around the weather. However, once we got close to the weather nothing can beat having onboard radar.