GPS/XM Weather Question

For those of you who have XM weather integrated with your GPS.

Do you use the weather information to paint a big picture of what's going on
around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
circumvent this line of storms."

Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Realistically, since there is a delay between when the radar picture was
taken and when you got the information, how close are you comfortable
cutting things when relying on XM weather?

Kyle Boatright wrote:

For those of you who have XM weather integrated with your GPS.

What about those of us who have WSI downlinked NEXRAD displayed on moving
maps? Are we qualified to answer or are you specifically interested in XM
users only?

--
Peter

Nexrad XM datalink could be as much as 10 minutes old. So, no, you
cannot use it to buzz between cells. It is a strategic tool, not a
tactical tool. Flying 50 miles thataway is a much better plan.


Kyle Boatright wrote:
For those of you who have XM weather integrated with your GPS.

Do you use the weather information to paint a big picture of what's going on
around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
circumvent this line of storms."

Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Realistically, since there is a delay between when the radar picture was
taken and when you got the information, how close are you comfortable
cutting things when relying on XM weather?

Kyle,

I have XM via the Garmin 396 and in the panel mounted Avidyne EX 500. They
both display the same nexrad but with the 396 I get more useful information
(cloud cover, storm cell heights & direction of movement, airmet & sigmet /w
text and more). The ideal use is to avoid the areas of bad stuff, which is
how I always intend to use the information. That being said, it has gotten
me thru some tight spots and around cells while in IMC. I would have been in
those situations even without the XM weather, so I was very glad to have it
available. I would never suggest that downloaded NEXRAD be used to pick a
2 mile corridor between 2 cells but it is a nice thing to have when things
do get nasty. I did a lot of observation of storm cells while in VMC and the
NEXRAD was quite accurate (all this was done before paying any attention to
it while in IMC). It's just another tool but only to be relied on to avoid
bad areas not to pick your way around bad things.

Mark
N28409
WC5I

"Kyle Boatright" wrote in message
...
For those of you who have XM weather integrated with your GPS.

Do you use the weather information to paint a big picture of what's going
on around you. I.E. "If I fly 50 miles thataway, it looks like I'll be
able to circumvent this line of storms."

Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Realistically, since there is a delay between when the radar picture was
taken and when you got the information, how close are you comfortable
cutting things when relying on XM weather?

"Peter R." wrote in message
...
Kyle Boatright wrote:

For those of you who have XM weather integrated with your GPS.

What about those of us who have WSI downlinked NEXRAD displayed on moving
maps? Are we qualified to answer or are you specifically interested in XM
users only?

--
Peter

All answers are welcome. I'm simply trying to get a feel for the usefulness
of this kind of technology.

KB

Kyle Boatright wrote:
For those of you who have XM weather integrated with your GPS.

I've got XM on the MX20

Do you use the weather information to paint a big picture of what's going on
around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
circumvent this line of storms."

I frequently zoom out to see "if it's bad out there" however, trying
to use NEXRAD to pick your way through things is folly. In military
sense, it's more STRATEGIC than TACTICAL.


Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Two miles would be cutting it close (especially if they were t-storms).

I have on board radar as well as Nexrad. As all of the others have said, the
XM is good for the big picture, but on board radar is more useful for
avoiding cells up close.

This is particularly true at night, when the radar becomes more important in
IMC. Both of them have important information, but separate applications.

Ron Natalie wrote:

I've got XM on the MX20

Ron, what are you using for your XM receiver, a Garmin x96 or some other
receiver?

Also, what weather products are available on the MX20 using the XM
receiver? NEXRAD, TAFs, and METARs, obviously, but what about lightning,
satellite images, winds aloft, and pireps?

Since WSI reversed engineered weather into the Garmin GNS430/530, Garmin
stopped offering MX20 software updates for WSI weather, which prevented the
display of the newer WSI weather features such as lightning, pireps, winds
aloft, etc.

--
Peter

Kyle Boatright wrote:


I'm simply trying to get a feel for the usefulness
of this kind of technology.

I had the WSI receiver displaying graphical and textual weather on the MX20
moving map installed in my Bonanza two years ago and have been using the
aircraft heavily to commute for my business, flying at least twice a week
for the last two years (about 95% of the total time) in the Northeast US.

Disregarding for a moment my belief that I chose the "Betamax" of the
downlinked weather technology, I am continually impressed with how
downlinked NEXRAD allows me to launch more confidentially. As long as the
refresh rates remain within the 4 minute period (the WSI sometimes doesn't,
especially on long x/c's across the US mainland), the big weather picture
is accurate enough to give me the information to make proper decisions.

Last year, I was about 20 minutes outside my home airport when two t-storm
cells merged into one large one right over the airport. I could see the
tops of the storm up ahead, but the NEXRAD provided me with the fact that
the cell actually sat right over the airport (as opposed to being east or
west of it).

In watching a few refreshed screens, it was clear that the cell was not
moving that fast, so I requested a diversion to an airport to the south (I
was IFR), where I landed and waited about 30 minutes for the cell to
finally move northwest of my home airport.

I have plenty of similar experiences but in summary, if you want more
utility out of your aircraft, the confidence to have the big weather
picture and you fly outside your local traffic pattern, you should
seriously consider installing downlinked NEXRAD (IMOandE, of course).

--
Peter

I compare the XM big picture with our stormscope and my eyeballs (if I can).
I'd never use any of the above to buzz between two "cells". I will use it,
to a point and in non convective situations, to direct me towards lower
levels of rain intensity. It is a great tool for inflight decision making.

Recently on a flight from MI to WI across LM, a storm was working it's way
from south western WI northeast up through the Madison area. As we left MI,
we saw it developing and noted how slow it was traveling. ATC was
announcing Airmets and Sigmets for our entire route due to the approaching
storm. The XM weather not only let us avoid it, but showed us that we
wouldn't even need to deviate our course due to the slow movement. The
storm stayed south long enough for us to get home and we never came within
30 miles of it. The storm dumped over 3" of rain on Madison while we flew
ahead of it through layered CU. Without XM we probably would have sat in MI
watching the Weather Channel and waiting for that monster to pass.

My experience is that XM makes more flights possible and manageable, but it
is in no way an excuse to get any closer to thunderstorms than you would
when you can see them out your window.
Jim

"Kyle Boatright" wrote in message
...
For those of you who have XM weather integrated with your GPS.

Do you use the weather information to paint a big picture of what's going
on around you. I.E. "If I fly 50 miles thataway, it looks like I'll be
able to circumvent this line of storms."

Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Realistically, since there is a delay between when the radar picture was
taken and when you got the information, how close are you comfortable
cutting things when relying on XM weather?