20040415: IDV effots

Hi Jim-

Jim Steenburgh wrote:

>    Turns out that our lab machines have a different driver than my 
> office machine.  IDV is running slicker than snot on them.  My office 
> machine is moderately old.  Thus, let's not waste time trying to get it 
> running on it.

That's fine by me, but if you change your mind, we're here to help.

>    To start, I've been playing around with the skew-T viewer.  It's 
> definately cool to surf around the world for examples.  I suppose this 
> can be done in N-Sharp, but for whatever reason, IDV "encouraged" me to 
> do it.  A big improvement over N-Sharp is the fact that the parcel path 
> moves when you alter the sounding...I like that very much.

Glad to hear it.  Unfortunately, Steve Emmerson did most of the
work on the skew-T and no one has done much with it since he
was re-assigned to the LDM project.

>    A few questions/comments/requests based on feedback from my students 
> and I:
>
> 1. Is there a way, after you've altered the sounding, to reset it to the 
> original data?

Yes, but not through the user interface. ;-)  I'll see if there
is a way I can add that in for the next release.  I've wanted
to do it also.

> 2. CAPE is not calculated if the CIN is 0.  This is a problem in our 
> part of the world where soundings frequently have CAP but no CIN.

Okay, thanks for letting us know.  I'll look into how CAPE is being
calculated.  Are there other features you'd like for the calculation
of CAPE (e.g., specifying the layer or something like that).  I'm not
promising, just asking. ;-)

> 3. Is it possible to do overlays?

Not at present.  You can load in multiple soundings and cycle
through them.  Just select a bunch in the chooser.  So, if I
want to compare the 00 and 12Z sounding, I just load both
and cycle.  I find that having too many lines on the skew-T
(i.e. overlay) is confusing.  While I'm writing this, I was
thinking that it would be nice to have a quicker way of cycling
through the soundings.  We recently added something to the
plan view controls for cycling through levels, and I'll look
into adding that to the skew-T control as well.

That said, we should look at overlays because it would be good
to be able to overlay a real sounding on the model sounding.

> 4. There was interest amongst the students to be able to be able to 
> display the forecast temperature based on the available, clear-sky 
> radiation.

I'm not sure what you mean here.  Give me the formula/method
and I'll see what I can do.

If you have other enhancements to this control, let us know.
I'll add them to the list and bring them up with the Steering
Committee.

BTW, it would be better if you send these questions to support
instead of me directly in case I'm not here.  If you reply to
this message, it will happen automagically.

Don
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> Date:    Thu, 15 Apr 2004 09:01:55 MDT
> To:      address@hidden
> From:    Jim Steenburgh <address@hidden>
> Subject: Re: 20040415: IDV effots
>
> Don:
>
>     Concerning your response to item 2, there's probably some interest 
> in the community to calculating CAPE based on the average potential 
> temperature and specific humidity in the lower layers.  I thought this 
> was handled by your fancy "below the cursor option".  If it is not, it 
> would be good to add as the user could select the depth of the layer 
> overwhich to do the averaging.
>
>      I'll have to do some digging to get a formula for the surface 
> temperature forecast.  Such a forecast can be done in N-SHARP, so 
> perhaps Chiz can dig up the routine from GEMPAK.