EXPERIENCE SUMMARIES
HOLLISTER and AVENAL Ramy Yanetz May
22, 2001
[For flying out of Hollister] I use the Avenal TIP instead of
Hollister especially on high pressure days with a strong low-level inversion like we had the last couple of
weeks. The TIP for Hollister is miserable compared to the Avenal one,
and indeed there was hardly any lift in the Hollister valley. The
reason for the difference is obviously the marine layer, but it is completely
blocked 25 miles away from Hollister on the east side of the Diablos.
So if someone really wants to soar these days, all he needs is to look
at the Avenal TIP and take a high tow and glide 25 miles to Panoche where
it is booming. I'm talking 10 knots lift! Interestingly, the
Avenal TIP is more accurate for Panoche and Hernandez, where the max altitudes
are usually much higher than over Avenal itself, which works great for
XC planning out of Hollister. Empirically I found that the mountains
(especially Panoche and Hernandez) gets the TIP=0 and Avenal gets the TIP=-4
at best. Makes sense to me...
The only unknown is if this is also true for the whole summer. Last summer and this summer as well I will be flying at Minden, so unless someone from Hollister will be willing to take a high tow and glide to Panoche, we will never know.
Hollister is known for poor soaring conditions most of the summer, but Panoche and Hernandez may be still booming. Hopefully someone will try it out.
DrJack sez: Makes sense to me too. Thanks to Ramy for sharing
his extensive experience in the region SE of
Hollister. Avenal users might want to compare this to their experiences in the
mountains west of Avenal.
WILLIAMS Milt Hare Feb
12, 2002
After using them during the last year, I feel that TIP and BLIPMAP are
normally the best forecasts that are available - though the "mountain"
Williams TIP has problems in some weather conditions and the "valley"
Williams TIP has difficulties with the summer valley inversion.
We are working on the types of weather systems that cause problems,
but generally speaking the predictions have been good. They have
alerted me to many great days when I wouldn't normally have spent the
time to do a proper forecast.
During the winter, I think the "valley" Williams TIP is probably more
accurate than the "mountain" Williams TIP, since the calculation we're
using was 'tuned' during the summer conditions and is based on
Marysville, which is a long ways from Goat Mountain (we do that so we
get a reliable surface temperature prediction since we haven't found
one actually in mountains). Normally, if the "mountain" Williams
TIP prediction is unusually high (like 12,000-14,000 feet in January)
you should check it against BLIPMAP, or use some other source to
verify it. You can also look at the TIP's lapse rate section to
evaluate the airmass stability.
DrJack sez: For those unfamiliar with the two Williams
TIPs, the regular or "valley" Williams TIP is intended to represent
conditions in the Central Valley, where the gliderport is located,
whereas the "mountain" or MTwilliams TIP is intended to represent
conditions in the higher terrain northwest of the gliderport.
WILLIAMS Milt Hare March
22, 2002
Read Milt's
posting to rec.aviation.soaring to learn about his experience
using TIP and BLIPMAP to forecast soaring conditions at Williams over
the last year.
SUBMISSIONS
Descriptions of your TIP usage based upon
your flight experience which will be useful to other pilots can be
sent to the page maintainer, Jack Glendening
for posting. Please remember that the purpose of these postings
is to help other pilots utilize the TIP forecasts for their own
flying, not for you to simply describe a great flight you had since
other forums exist for that purpose. Distillations of experience
gained over many flights are especially solicited, but individual
flights which illustrate TIP usage can also be posted. Please
consider how your posting can be most useful to others: give specific
locations (particularly whether over flat or mountainous terrain), any
cloud influence, and whether the flight altitudes reached correspond
to the TI=-4 or TI=0 or other TI height (preferably using the TIP's
post-analysis). And, of course, give the site you are flying out
of.
Link to a description of the TIP program
Link to TIP Sounding Analysis webpage
Link to the latest TIP Forecasts, a listing of all TIP sites, and TIP email subscription information
Link to DrJack's home page