On Tue, 21 Aug 2007 03:15:51 -0400, "Roger (K8RI)"
wrote:

On Mon, 20 Aug 2007 01:37:10 -0400, Don Byrer
wrote:


Nexrad typically takes ~6 minutes per scan when wx in area...10 min in
clear air mode. The time stamp is from the start of the scan..

Internet subscription (WeatherTap) Usually runs on the order of 4 to 6
minutes when weather is in the area. Doesn't seem to matter how busy
the Internet. It's typically well over 10 when not much is happening.

So you are seeing it too...
I must correct: It IS possible to get base reflectivity (from one
slice) in less than 6 minutes...but if you are looking at composite
reflectivity (all the slices mosaic'd on top of one another) it's 6
minutes.

You have to be careful depending on NEXRAD displays. Storms can and
do sometimes jump ahead of a front by as much as a 100 miles in 5 to
10 minutes. Storms associated with instability can (and do) sometimes
cover very large areas in 5 to 10 minutes. I watched a line over 50
miles wide and over 150 miles long extending from around Muskegon to
Oscoda MI, form in just over 5 minutes.

I'm a pilot as well as a wx geek and a wx/ATC radar tech...I can't say
I've EVER seen a storm move 100nm in 10 min...that would be 600nm/hr!
you must have been "embellishing " a bit

In an hour-2 YES...and those were nasty!

Now...popping up in 10 min...100nm ahead of a front...all the time

ditto the rest of the paragraph tho... "popcorn" storms can be nasty.



Even when using NEXRAD the pilot really needs to know the lifting
factors/instability, laps rates, dew point and temperature as well as
frontal movement to plan very far ahead and remain safe in warmer
weather flying

Satellite weather in the cockpit is great, but you still need to know
a lot about the weather conditions to augment it.


Got it 100% Roger!

-Don B

Don Byrer KJ5KB
Radar Tech & Smilin' Commercial Pilot Guy
Glider & CFI wannabe
kj5kb-at-hotmail.com

"I have slipped the surly bonds of earth; now if I can just land without bending the gear..."
"Watch out for those doves...smack-smack-smack-smack..."