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...so 2
six minute scans, plus a few minutes network delay =17 is quite
possible...not that it's good.

Over the public internet, I usually see NEXRAD data within 10 minutes
of the scan start time....but sometimes 20 mins if the net is

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.
I've been playing around with SWIFT WX for the past couple of weeks
but haven't used it enough to see how well it compares.

slow/busy. If you can time lapse the data, it gives you a good idea
where it's going anyway...and if it's THAT close you are a braver
pilot man than I am.

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.

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.



--Don Byrer
Former NEXRAD techie





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..."