Nexrad
 

Has anyone here noticed that since ATC began using NEXRAD radar the increase of "moderate, heavy, extreme" precipitation reports when there is no detectable precip (or turbulence) at all? (My point is not an ATC issue, but a NEXRAD one.)

Has anyone here felt that on-board NEXRAD, such as XM, often highly overstates the intensity level of precipitation?

I find that everything on the nexrad is usually exaggerated when compared to the onboard radar. I have no problem with that though, it is always accurate and helps my situational awareness.

When I was doing some flying over the gulf of Mexico, we had the Nexrad through XM and it was worthless. The lag time put me in the middle of magenta cell and it was deffinatly a rough ride. Usually ATC will give us the precip call but most of the time we are on top of it. Still at least they have some weather depiction.

XM coverage in the gulf and carribean is spotty at best but is getting better.

NexRad is only as good as the system it is sent through. Some spots are slow with reception. So getting timely information that's within minutes of accuracy is rare. I always plan for it to be 5 minutes ahead of where it usually is, and it works fairly well.

As stated above, it will also indicate a slightly worse condition than is actually out there.....definately in the name of liability. On-board is really the true source of tactical information if you are planning on flying close in to any precip anyways. NexRad to me is strictly for long-term planning.

I too think nexrad is good for "strategic" planning, but you need "real" radar for "tactical" planning.

I have noticed a slight increase in advisories from ATC and it usually seems to be below our cruise altitudes. I think NEXRAD will "overstate" the precip because it's an extremely sensitive instrument. So it may pick up dense clouds where other radar's won't.

FWIW, NEXRAD's advantage over conventional wx radar is it detects the movement of the precipitation within the individual cells. So, although any radar will show time-lapse movement of a wx system, NEXRAD will show water droplet movement. This helps in detecting rotation prior to any tornadoes forming.

XM Nexrad radar is a good tool to use to get an overall picture. I will use it up to 80 miles from the weather system then switch to the onboard radar to pick my way thru the weather. It is nice because it will tell you cell movement direction and speed, tops, and hail predictions. It also helps tell you if the weather system is intensifying or weakening.

Our Nexrad (Proline 21 aircraft) is hypersensitive. It displays least 2 steps up from what is actually out there ie. light rain shows as yellow. We routinely fly through areas depicted as yellow on the Nexrad, that don't even paint on the ship's radar, with nothing more than light rain/mist. And this is in the teens and 20's.

Just to put my two sense in...:) We ususally try to use a combination of the two, Nexrad for overall picture in lieu of the onboard wxr, it has been working for me so far but I have noticed the differences between the two I just try to take each for what is worth and use what will best benefit me depending on scenario.