View Full Version : Weather radar usage
varigflier
8th Jan 2008, 16:49
I was wondering what formulas or tricks you guys use to find out cloud tops etc when using the weather radar.
I have heard there are quite a few of them......
You cannot determine 'cloud tops', only where the water concentration is - use 1 in 60 rule.
varigflier
8th Jan 2008, 17:29
I found some interesting websites.
www.radar4pilots.com
http://www.gapan.org/Papers/Weather%20Radar.pdf
nugpot
8th Jan 2008, 19:33
You can also look here:
http://www.pprune.org/forums/showpost.php?p=658373&postcount=5
misd-agin
8th Jan 2008, 22:18
I use -2 tilt and -2/-4 gain(calibration). Full sensitivity, or three to five clicks anti clockwise on the calibration knob(MAX/-2/-4 on calibration scale).
The -2 tilt is for the 40 mile range. If something paints at 40 miles, with -2 tilt, I turn.
Used to use -1 tilt. That was too close a couple of times.
You need some time to get used to it. :rolleyes:
SuperRanger
9th Jan 2008, 04:21
most times even if you can estimate the tops, you cant climb over it anyway. it's easier to just go around it. it think thats what the wxr are meant for.
SR
stator vane
9th Jan 2008, 06:19
used by certain checkair-persons whenever they have to start digging a bit deeper to score some points of self-confirmation when lacking in areas that count.
one should be able to look at said build up and within "seconds" determine whether one should go around or can go over.
same persons using this technique should come to same conclusion that is arrived at with "raw data" eyes.
if not, natural cause and effect should weed them out of genetic pool or if gracious, instruct them.
PantLoad
9th Jan 2008, 13:12
Depending on where you are in the world, the season, etc., you can get your XXX kicked trying to top thunderstorms. It's safe to assume that ANY thunderstorm can give you a bad case of heartburn with as little as 5000 feet above the tops of the clouds. And, consider crossing the Rockies in the spring or fall....you get a fast-moving front with the associated squall line....and you can get severe turbulence up to 8000 to 10,000 feet above the tops. (Yes, this is not theory...it's actually happened!!!)
So, it's true, unless you're an SR-71, it's better to simply go around 'em. It's a nice academic exercise to calculate the tops using the RADAR tilt. Keep in mind, tropical thinderstorms have tops that paint a lot better than early-spring boomers over the Rockies. (They're relatively 'dry'.)
Fly safe,
PantLoad
misd-agin
9th Jan 2008, 14:28
Company gave us a card to estimating storm tops. Thinking "wow, that's way cool(I was younger then....)." Archie Trammel had worked a deal with the company.
So on that trip we're coming back from Europe to the U.S. Over Canada we spot a storm ahead. "Get out your card and figure out the tops. Don't tell me what you get and we'll see who's closer when we go by the storm." Ok, bet's on! Anything to keep you amused by then is greatly welcomed.
The copilot and I (relief pilot) start calculating. Radar tilt to get ground return at the mileage your flying... raise tilt until, etc, etc.
Storms just sitting there. No vertical developement.
Cruising at probably FL 350(?) we pass the storm. "So, what did you get?" Both of us had the storm top around 30,000-32,000. In other words safely below us when it was well above us.
I threw the card away.
Like they said, "it's an academic exercise".