Outstanding Soaring: California Mojave, Owens Valley, Western NV -Fri-Sun 08/26-28

On Aug 28, 2:23*pm, Alex wrote:
On Aug 27, 6:19*pm, Mike the Strike wrote:









On Aug 26, 4:58*pm, Alex wrote:

On Aug 26, 3:04*pm, Ramy wrote:

On Aug 26, 8:35*am, WaltWX wrote:

Ramy,

I agree with your assessment. My focus for the good weather is aimed
at the Owens Valley, and Mojave Deserts (south of Bridgeport). *More
moisture spreading over entire area on Saturday with cloud bases
15,000-16,000 north of Bishop instead of 17,000msl. Widely scattered
TS in the usual hot spots but the cells should be fairly small and
short lived. *Sunday, as Alex pointed out below, looks a little drier
everywhere... still at least a very good to outstanding day.

Walt, Wx

On Aug 25, 11:51*pm, Ramy wrote:

On Aug 25, 5:45*pm, WaltWX wrote:

Take a look Dr Jack...

Outstanding soaring weather Fri through Sun. *Lift rates 700-800fpm
average... much stronger in those 10 per cent...

It's a toss up between Fri and Sunday. *The Mojave Desert, Owens
Valley and Western NV show full cu coverage bases 15,500 to 17,500. It
appears to be dry enough that only isolated thunderstorms will form in
the normal "hot spots". *Early trigger times also.

I reviewed Dr Jack this afternoon with a long ago crew of mine, John
Halcrow. *For Crystalaire, the pattern on Friday looks as good as I'v ever seen it. *BL (thermal) max heights 17,500msl (of course cloud
bases will limit altitudes to a little lower).

I'm coming back out Saturday to give my 750 km triangle another try
from Inyokern (please... leave me room for an 11:30am takeoff

Walt Rogers, WX

I don't see the same outstanding conditions when reviewing the NAM
blipmap, especially for going north towards Minden. Bases only 15-16K,
lots of moisture with potential for overcast and OD and stronger wind
to the north. Could still be good but probably not as good as it was
the last few days.

Ramy- Hide quoted text -

- Show quoted text -

One little known secret of Dr Jack Blipmap is the "Total Cloud Cover"
parameter. This is one of the most reliable parameters I've seen to
detect overcast. If there are white areas you are pretty much
guarantee that there will be at least some level of overcast. It does
not tell if it will be high cirrus or mid level overcast, and how
thick it will be, nor if it will be persistent or short lived. But it
hardly ever fails to detect that there will be some degree of overcast
in the area. It indicated *successfully today pockets of overcast
especially in the southern zones of region 11 and 12, and more so
tomorrow over the central Sierra. None for Sunday.

For those who prefer looking at the RASP, besides the Avenal one,
there is one which covers the whole Sierra:http://www.norcalsoaring..org/BLIP/SIERRA/index.html
It has 'BL Cloud Cover' but I did not use it enough to confirm if it
provides the same as the NAM Total Cloud Cover.

Ramy

Also on the Dr. Jack RASP sites, if the operator has set up locations
for plotting forecast
soundings as *Skew-T diagrams, *you can see on the left side of these
diagrams
black lines corresponding to forecast cloud layers. *These *try to
forecast both the heights and thicknesses *of cloud layers. * *These
include *cloud layers that
are above the "boundary layer" that most of the blipmap diagrams
concern themselves with, *such as high cirrus layers. * *If there is
also a similar layer marked in green over on the left side
representing *"cloud water in g/k", that seems to correspond with the
chance of
precipitation. * An example of this could be seen today on some of the
soundings from the Avenal RASP, such as this one:

http://alcald.homelinux.org//RASP/AV...8.curr.1400lst....

Alex Caldwell

Rapid Refresh plots have this and more and are a lot more accurate
than RUC or NAM based Blipmaps. *It'll be nice when RR goes online and
replaces RUC.

Mike- Hide quoted text -

- Show quoted text -

The RASP blipmapshttp://www.drjack.info/RASP/index.html
are quite different than the RUC and NAM based blipmaps.
I'm not an expert on this stuff, so take this with a grain of salt,
but I have been running the RASP on my own for a
few years now for our club. There appear to be some misconceptions as
to the differences between Dr. Jack's *RASP blipmaps and the orginal
Dr. Jack RUC and NAM blipmaps, as well as the relationship of the RASP
to the new Rapid Refresh.
I apologize in advance to Dr. Jack, *if anything I'm saying below is
bogus.

The RASP blipmaps (as opposed to the original Dr. Jack RUC and NAM
blipmaps), use use a "WRF"
computer model (version 2) *which is *the same model the Rapid Refresh
is using, except Rapid Refresh is using a newer
version, WRF version 3.2+ . *Some people running the RASPs are
switching over to the WRF version 3 also.
The RASPs in the US are generally "initialized" using ETA (NAM) "grib
files". In Europe the GFS model is generally used for
initialization. * But
from there on, *the atmospheric physics calculations
are done based on the WRF model, not NAM or RUC. Dr. Jack has also
used the RUC *instead of ETA or NAM to initialize the *WRF
model in some experiments he has done. *Basically, what Dr. Jack did
with the RASP is to take the WRF model, and
have it output the various blipmap "parameters" he developed that are
of particular interest to soaring pilots, *plotting them using suite
of *plotting programs
called "NCL". * The advantage of the RASP over the original RUC and
NAM blipmaps is whatever improvement the WRF model offers, plus the
much
higher resolution - generally 4km for starters,
and on up from there, as opposed to 20km with the original blipmaps.
This allows much more detailed computer modeling, *with the finer
overall grid resolution, and
much more detail with respect *to the
effects of local terrain, including terrain heights, terrain contours,
terrain compostition and soil types, seasonal variations in albedo
etc. *The big disadvantage of the
RASP is that it requires tremendous computing resources to plot this
level of detail over the whole U.S. or the globe, and
until recently, this would bring *even the *government's *computers to
their knees. *Hence,
you see volunteers running RASPs for small local areas of interest on
their own. *The new
Rapid Refresh appears to be able to overcome that limitation by being
able to run a 3km resolution WRF model for the whole US, also
including
things like radar data that were not available before.
The parameters the Rapid Refresh group are publishing are interesting,
and many are already useful to glider pilots, but they don't have the
same
type of soaring centric information available that Dr. Jack developed,
such as his "Cu Cloudbase where Cu potential is 0" and the many
others
we've come to know and enjoy from his work. *An obvious possible
future project might be to take the new Rapid Refresh system and get
the type
of output we've gotten from the blipmap soaring parameters. *I suspect
the RapidRefresh team won't do this for us on their own, unless maybe
they have a
fanatic soaring pilot on their programming staff!

Alex Caldwell
Central California Soaring Club
Avenal, CA, USA

Alex:

Thanks for your comprehensive explanation.

I have only recently had the opportunity to compare the operational
models with RASP model output for southern Arizona (Dave Leonard is
running it for us on his server). I had been using RR1 skew-T plots
for over a year now and have found them generally much more accurate
than any of the previous models. More recently, I have been looking
at all the RR output fields and find them very useful. The more rapid
cycle has enabled me to keep up with changes when the other models lag
behind.

My observations have been that the RASP output is very comparable to
RR (know I know why!) and nearly always better than any of the other
models. NAM has been generally best here, but RUC sometimes is
better, but neither is as good as the RASP output. It certainly is
very nice to have the soaring parameters.

The main problem I have with the RASP is the same as the original Dr.
Jack's output - the abysmal maps. I am looking forward to RR going
operational and getting someone to produce nice interactive maps from
the output. I wish I had more software skills, but it's way beyond
me!

Mike

Alex,

You are right about RASP and the valuable visualization of soaring
parameters Dr Jack has given it (and BLIPMAP). If we could get timely
access to the high resolution model data and visualize it with the
soaring parameter point of view, this would be an alternative to
running RASP on smaller systems. You are right on all your comments
regarding RASP and how it relates to the big NWS NCEP models... except
for one point. The Rapid Refresh model (RR) has been running
experimentally for two or three years and is scheduled to replacee the
RUC in November 2011. However, it is only 13km resolution. Another
model, the High Resolution Rapid Refresh (HRRR - phonetically sounds
like "her") is basically the same as the RR but runs on a 3km grid
hourly. It is initialized by the RR.

To be continued...

Walt Rogers, WX

On Aug 30, 10:58*am, WaltWX wrote:
Alex,

You are right about RASP and the valuable visualization of soaring
parameters Dr Jack has given it (and BLIPMAP). If we could get timely
access to the high resolution model data and visualize it with the
soaring parameter point of view, this would be an alternative to
running RASP on smaller systems. You are right on all your comments
regarding RASP and how it relates to the big NWS NCEP models... except
for one point. *The Rapid Refresh model (RR) has been running
experimentally for two or three years and is scheduled to replacee the
RUC in November 2011. However, it is only 13km resolution. Another
model, the High Resolution Rapid Refresh (HRRR - phonetically sounds
like "her") is basically the same as the RR but runs on a 3km grid
hourly. It is initialized by the RR.

To be continued...

Walt Rogers, WX

Thanks Walt.

Your presentation on this topic for the 2010 SSA Convention was/is
really great. In case
anyone has not seen it and wants to read more about it, Walt's
presentation on "Soaring Forecasts in the
NexGen Era" is he

http://www.ssa.org/files/member/NWS_SSA_Show.pdf

On Aug 30, 1:07*pm, Alex wrote:
On Aug 30, 10:58*am, WaltWX wrote:





Alex,

You are right about RASP and the valuable visualization of soaring
parameters Dr Jack has given it (and BLIPMAP). If we could get timely
access to the high resolution model data and visualize it with the
soaring parameter point of view, this would be an alternative to
running RASP on smaller systems. You are right on all your comments
regarding RASP and how it relates to the big NWS NCEP models... except
for one point. *The Rapid Refresh model (RR) has been running
experimentally for two or three years and is scheduled to replacee the
RUC in November 2011. However, it is only 13km resolution. Another
model, the High Resolution Rapid Refresh (HRRR - phonetically sounds
like "her") is basically the same as the RR but runs on a 3km grid
hourly. It is initialized by the RR.

To be continued...

Walt Rogers, WX

Thanks Walt.

Your presentation on this topic for the 2010 SSA Convention was/is
really great. *In case
anyone has not seen it and *wants to read more about it, Walt's
presentation on "Soaring Forecasts in the
NexGen Era" is he

http://www.ssa.org/files/member/NWS_SSA_Show.pdf- Hide quoted text -

- Show quoted text -

And I stand corrected. Walt forecast was right on at least for Sat and
Sun with OLC showing 800-900+ km flights out of Inyokern.
The NAM Total Cloud Cover I mentioned earlier was correct also but
wasn't as much of a factor as I expected. Glad I didn't listen to
myself and went flying anyway :-)

Ramy

The main problem I have with the RASP is the same as the original Dr.
Jack's output - the abysmal maps. *I am looking forward to RR going
operational and getting someone to produce nice interactive maps from
the output. *I wish I had more software skills, but it's way beyond
me!

Mike- Hide quoted text -

- Show quoted text -

Regarding the Maps, several RASP operators are coming up with some
quite
nice user interfaces for the RASP using Google Maps. They have made
this
code available to others, so maybe this could also eventually be
applied
to the HRRR as well.

Check out the UK RASP by Paul Scorer:

http://rasp.inn.leedsmet.ac.uk/RASPt...SPtableGM.html

and the Central Italy RASP by Andrea Barcellona:

http://www.ilpulcino.org/meteo/blipmaps

Alex Caldwell

On Wed, 31 Aug 2011 09:22:58 -0700, Alex wrote:

Check out the UK RASP by Paul Scorer:

http://rasp.inn.leedsmet.ac.uk/RASPt...SPtableGM.html

Personally, I prefer the older RASPtable,

http://rasp.inn.leedsmet.ac.uk/RASPtable.html

The map may be smaller than RASPtableGM and have no identified points
apart from the places where soundings are available, but the coloured
overlays are much brighter and easier to read. IMO this outweighs all
else.

My problem with RASPtableGM is simply that the colours are so delicately
pastel that they disappear into the maze of towns and motorways on the
map and so become needlessly difficult to read. The Central Italian RASP
maintained by Andrea Barcellona is much better: I could easily live with
that.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Aug 31, 9:22*am, Alex wrote:
The main problem I have with the RASP is the same as the original Dr.
Jack's output - the abysmal maps. *I am looking forward to RR going
operational and getting someone to produce nice interactive maps from
the output. *I wish I had more software skills, but it's way beyond
me!

Mike- Hide quoted text -

- Show quoted text -

Regarding the Maps, several *RASP operators are coming up with some
quite
nice user interfaces for the RASP using Google Maps. *They have made
this
code available to others, so maybe this could also eventually be
applied
to the HRRR as well.

Check out the UK RASP by Paul Scorer:

http://rasp.inn.leedsmet.ac.uk/RASPt...SPtableGM.html

and the Central Italy RASP by Andrea Barcellona:

http://www.ilpulcino.org/meteo/blipmaps

Alex Caldwell

This is great, especially the Italian one. I would love to have such
maps for the NAM blipmap as well. I still find the NAM to be the most
accurate model, and it is available up to 3 days out.

Ramy

On Aug 26, 8:01*am, Alex wrote:
On Aug 25, 5:45*pm, WaltWX wrote:





Take a look Dr Jack...

Outstanding soaring weather Fri through Sun. *Lift rates 700-800fpm
average... much stronger in those 10 per cent...

It's a toss up between Fri and Sunday. *The Mojave Desert, Owens
Valley and Western NV show full cu coverage bases 15,500 to 17,500. It
appears to be dry enough that only isolated thunderstorms will form in
the normal "hot spots". *Early trigger times also.

I reviewed Dr Jack this afternoon with a long ago crew of mine, John
Halcrow. *For Crystalaire, the pattern on Friday looks as good as I've
ever seen it. *BL (thermal) max heights 17,500msl (of course cloud
bases will limit altitudes to a little lower).

I'm coming back out Saturday to give my 750 km triangle another try
from Inyokern (please... leave me room for an 11:30am takeoff

Walt Rogers, WX

Walt,

I ran a 4KM resolution RASP last night for AVENAL that goes 2 days
out. It is centered on AVENAL, but covers the
high desert area around Edwards and the S. Sierra and Owens Valley up
to N. of Mono Lake. If I'm interpreting
it right (which is highly open to question), it's saying Friday and
Saturday, there should be good cumulus in the desert area in Region
12, *but it should *be drying out in Region 12 by *Sunday. *On Sunday,
the better cumulus will be more up North in Region 11. *On Friday,
there may be some higher level overcast from subtropical moisture
coming in from the SW with some chance of OD along the coast range
near Castle Peak and New Cuyama and over the S. part of the Sierras.
The higher level overcast shows up on the Skew-T sounding forecasts on
the RASP, *but not on the regular blipmaps. *This should be gone on
Saturday and Sunday. *Would be interested in what you think about it.
Also any pilot reports after the weekend is over would be interesting
to hear to correlate with the forecast.

http://alcald.homelinux.org/RASP/AVE...RASPtable.html

Alex Caldwell
Central Calif. Soaring Club
Avenal, CA, USA- Hide quoted text -

- Show quoted text -

Well the forecast for this labor day weekend looks epic for the
Sierras, much better than last weekend. High base cu along the whole
length of the sierra on Saturday and accross the Great Basin as well
on Sunday. Monday should be similar.