old NEXRAD

[Dan Luke[_2_]]

I saw some long NEXRAD update delays on the G1000 Saturday on a trip from
Mobile to Houston.

http://www.cessna.org/forums/attachments/526029-OldNEXRAD.JPG

Anybody else seen delays this long?

--
Dan
T-182T at BFM

[Dan Luke[_2_]]

Sorry, that link won't work for non-members.

Anyhow, the NEXRAD was 17 minutes long in the picture.

[cpw]

On Aug 19, 3:24 pm, "Dan Luke" > wrote:
> I saw some long NEXRAD update delays on the G1000 Saturday on a trip from
> Mobile to Houston.
>
> http://www.cessna.org/forums/attachments/526029-OldNEXRAD.JPG
>
> Anybody else seen delays this long?
>
> --
> Dan
> T-182T at BFM

We had some long delays flying to Independence, Kansas from Michigan.
Apparently there are some "black out" areas where nexrad isn't well
received.
CPW

[Don Byrer]

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
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.


--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...>"

[Gig 601XL Builder]

Dan Luke wrote:
> I saw some long NEXRAD update delays on the G1000 Saturday on a trip
> from Mobile to Houston.
>
> http://www.cessna.org/forums/attachments/526029-OldNEXRAD.JPG
>
> Anybody else seen delays this long?

I don't know if the two are related but I had some signal problems with my
car's XM radio on Saturday.

[Dan Luke[_2_]]

"Gig 601XL Builder" wrote:

>>
>> Anybody else seen delays this long?
>
> I don't know if the two are related but I had some signal problems with my
> car's XM radio on Saturday.

It wasn't a reception problem. Other WM Wx products were updating more
frequently; XM lightning, for example.

--
Dan
T-182T at BFM

[Roger (K8RI)]

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...>"

[Don Byrer]

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...>"

[Roger (K8RI)]

On Tue, 21 Aug 2007 23:50:20 -0400, Don Byrer >
wrote:

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

Not at all, but I don't think that's quite what I said, or at least
that was not my intention. I said "storms can jump ahead " and
probably should have said storm/cell formation can jump ahead, and "I
watched a line form". IOW a large area can go down in just minutes
giving the appearance the line is moving that fast. All too often we
think of a storm or line of storms moving, but many times what happens
with a large area of instability be it associated with a front or not,
they can give the impression of fast moving storms when it's really an
area of forming storms which was the case above.


>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...>"

[Don Byrer]

On Wed, 22 Aug 2007 19:57:37 -0400, "Roger (K8RI)"
> wrote:


>>
>
>Not at all, but I don't think that's quite what I said, or at least
>that was not my intention. I said "storms can jump ahead " and
>probably should have said storm/cell formation can jump ahead, and "I
>watched a line form". IOW a large area can go down in just minutes
>giving the appearance the line is moving that fast. All too often we
>think of a storm or line of storms moving, but many times what happens
>with a large area of instability be it associated with a front or not,
>they can give the impression of fast moving storms when it's really an
>area of forming storms which was the case above.
>

actually.. i think we are in 'violent agreement' :) Just describing
it differently...

but I would like to clarify...for those who arent wx geeks...

storms..or any wx...can't JUMP ahead...it may look that way cuz
nexrad's only painting it in full once every 6 mins. and add some
unpredictable network delay, whether you're at home or in the plane...

The speed of the storm may change, but it can't "jump" to a new
location.

With the right conditions....small intense storms may continually pop
up in front of the line...rain out and die., called..."popcorn
storms"

--Don





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...>"

[Blueskies]

"Dan Luke" > wrote in message ...
>I saw some long NEXRAD update delays on the G1000 Saturday on a trip from Mobile to Houston.
>
> http://www.cessna.org/forums/attachments/526029-OldNEXRAD.JPG
>
> Anybody else seen delays this long?
>
> --
> Dan
> T-182T at BFM
>

We had a storm blow through SW Michigan last Thursday. It was moving (according to the weatherman) 55 mph to the east.
They were showing real time doppler returns and it was moving fast. I would like to see NEXRAD returns for this one.
There is no way it would keep up. It only lasted overhead 5 minutes max, but it left trees down and power outages that
continue today.