Dr.Jack U.S. soaring forecast site - 1st year experience
by Milt Hare
(article posted to rec.aviation.soaring, March 22)
I've been one of the primary 'test pilots' here in California for the
past year for the new forecasting tools Dr. Jack has created. After
about 50 test flights, and gathering feedback from our soaring
community, I have no reservations whatsoever. They work, and they
will make a real difference to every pilot who understands and uses
them. We haven't been surprised by a good soaring day in Northern
California for a long time...
I think BLIPMAP will have a major impact on soaring here in three
1) For sites that do not have consistent soaring, accurate and
reliable forecasting allow pilots to plan ahead and be there on the
good days. It's amazing how many people can be sick if they know
early enough how good it's going to be... Not to mention lining up
tow pilots, etc.
2) Badge and declared task flights can use the best lift of the day.
BLIPMAP greatly simplifies task selection and gives you more
confidence that the lift will still be there late in the day to get
you home (or to take a tow at 8am).
3) Planning very long cross-country routes in areas affected by
thunderstorms. At Ely last summer, BLIPMAP accurately forecast the
location of thunderstorm areas, which is one of the major obstacles to
1000k+ flights in the desert (after seeing BLIPMAP at Ely last summer,
Ray Lynskey felt that it is a major advance in very long cross country
Here is a little more info for those who might be interested in the
best thing that has happened to soaring forecasts since cumulus clouds
John W. Glendening (Dr. Jack) is a research scientist who works at the
Naval Research Laboratory in Monterey, California. He specializes in
the study of boundary layer processes, among other things - that means
he actually studies thermals for a living. He knows a LOT about
thermals. Luckily for us, he is also a glider pilot and is very
interested in making soaring forecasts available to normal people so
we can go out and soar on the good days and stay home on the not so
Sometime during the year 2000 the Kevin Ford Thermal Index site went
down for what seemed like an eternity because of data source issues.
So Dr. Jack decided to write a version himself that would use
multiple data sources to avoid that problem. That is what got the
ball rolling - it hasn't been much more than a year since then, and he
has created a group of forecasting tools that are simply mind-blowing
- light years beyond anything I've ever heard of. Dr. Jack has worked
many hundreds of evening and weekend hours, including at least one
three day weekend (with great soaring I might add) to create these
gems, and I just can't believe he's done it. But he has, and now we
can all use them - fantastic!
We can now get early warning of possible good thermal conditions two
days ahead using the Thermal Index Prediction (TIP) program, and very
accurate graphical thermal forecasts for the following day starting at
11pm PST the night before using the Boundary Layer Information Program
Map (BLIPMAP). BLIPMAP forecasts the conditions HOURLY from 7am till
7pm, although some of those hours don't always get processed in time
to use them. Dr. Jack is also working on wave forecasting tools,
although they are pretty new and haven't been well tested as yet.
We've been testing these awesome thermal forecasting tools for the
last year here in Northern California and Nevada - primarily from
Williams and Hollister, with some testing in Minden and Ely. Dr. Jack
has just expanded one of them, the Boundary Layer Information Program
Map (BLIPMAP) to include the entire continental U.S., and we're
starting to spread the word now that we've gone through a season with
Here is a brief rundown of the tools he has created, and how we use
This gives detailed Thermal Index (TI) information for a given
location, and includes the forecast for the current day and estimated
forecasts for two days ahead. We use the one and two day forecasts as
an alert to start watching the weather closely if it is looking good.
The forecast for those days often change over time, but they are very
useful for an early warning that something good is on the way.
The TIP for the current day shows lots of information about the
current location, and uses the TI method (same approach as the Kevin
Ford program). It is based on two different forecasting models and
two surface temp sources, so it rarely actually goes down even if one
of the sources is down or late.
The TIP is pretty accurate, although we have had problems in some
weather conditions. On some occasions we have nice cold air at 4am
that becomes stable later in the day - by the time the hi temp of the
day shows up. Generally speaking, it's been very good. It also shows
up in email every day - completely automatic forecasts. Beats the
even the GSD site.
Last year we made a 500 mile and 473 mile flight out of Williams in
early April that would never have happened without the TIP.
IMPORTANT NOTE: If TIP disagrees with BLIPMAP, we go with BLIPMAP
every time since it uses Dr. Jacks new and much more accurate method
BLIPMAP and BLIP
BLIPMAP is awesome - you'll know what I mean once you see it for the
first time. Over the last year I have made so many great soaring
flights that were possible only because of BLIPMAP that I cannot thank
Dr. Jack enough. It is especially useful on marginal days when it's
hard to tell if it will be soarable or not - much better than a long
tow into the hills just hoping for the best.
The BLIPMAP is a map of a region (California and Nevada in my
case) that shows different colors that correspond to various thermal
parameters. There is one map for each of the following: Top of lift,
thermal strength, wind direction, wind speed, probability of serious
thunderstorms (CAPE), overdevelopment potential, estimated cloudbase,
convergence, heating, etc. It is based on the experimental GSD Rapid
Update Cycle (GSD RAP2) model which provides input parameters on a
20km (about 12 mile) grid for the continental U.S. The BLIPs are the
raw numbers for selected points that BLIPMAP is based on - we use it
for specific point testing and validation, and it also gives detailed
wind information for wave/ridge forecasts.
It comes out at about 10:30pm the night before (sometimes delayed)
showing the forecast for 1pm the next day. By early the next morning,
we can see forecasts starting at 7am till 7pm, although many of the
hours are not processed until later in the day. Normally I can see
7am, 8am, 9am and 10am, 1pm, 4pm and 7pm by the time I blast out the
door in the morning.
From this information, you can determine when the lift is going to
start, where the best place for a first thermal will be, how high it
will go and how strong it will be. Also, you can see when the day
will die, and how to get home. We sometimes use end of day
convergence to get home at Williams, and can forecast the convergence
line before we even head out for the day.
The worst aspect of BLIPMAP is that you rapidly become dependent on
it, and since our data source is an experimental data source it
sometimes isn't available (we're talking serious data here - 50MB
compressed file downloaded and processed per time period - 3 times per
hour during peak processing time). Sometime in the next few months
that model goes 'official' and we're expecting more reliable data.
If you are interested in these forecasting tools, take a look at the
site and see what you think. The BLIPMAP is the most awesome one.
The TIP is also worth a good look. There are also some new wave
forecasting tools that look great, although they haven't been really
tested - Sierras only for time time being.
Dr. Jack has written very extensive background information for all of
his creations at the web site - much more than most people can read.
These are complex systems, and it helps to understand them if you want
to use them properly. Luckily, you don't have to read the whole thing
to use these tools - they work well for many people who don't
understand how they work.
I want to thank Dr. Jack for an incredible effort, and even more
incredible results. For those of us who live hours from the
gliderport, accurate forecasting make a real difference in our ability
to enjoy this sport. Also, my friend Brian Choate at Webbnet has been
hosting the Dr. Jack site as a service to all of us, and we've
received a lot of support and feedback from our local soaring
community here in Northern California.
This is just the beginning... New 12km grid NAM models are becoming
available, which would allow more than 24 hour forecast BLIPMAPS and
possibly better terrain resolution. It is possible to produce
forecasts for individual ridges and mountains using input data from
the models (lots of work to make that happen). Dr. Jack is currently
running a number of experiments to see what is possible - I'd say just
about anything after what he has done in just the first year!
Warning: BLIPMAP is available in the U.S. only at this time. TIP is
available for some locations in the U.S. There are computer models
for most of the world and there is no reason it can't grow over time.
For now it's been a major effort just to cover the U.S.
I should note that predicting soaring
conditions is not always straightforward, BLIPMAP or no. I like to
say that predicting the weather is not like reading an airspeed
indicator. Milt brings to his forecasts the experience gained by
many days of comparing BLIPMAP, TIP, and NWS forecasts to actual
conditions, even on days when he was not flying himself.
First-time users will need to develop a similar feel for the
correspondence between forecast and actual conditions and develop a
feel for each forecast product's strengths and weaknesses (cloud
predictions being a significant weakness of all). Use of
multiple forecast information is also useful - for example, for his
longer (2-3 day) forecasts Milt relies upon the "forecast discussions"
provided on-line by NWS forecasters in addition to the TIP.
(For those who do not know him, Milt flies an ASH-25 open-class
sailplane out of Williams, CA.)
Link to other pilot flight experiences using BLIPMAPs.
Link to the nation-wide
BLIPMAP forecasts for different regions
Link to the latest BLIP
forecasts for individual locations
Link to the latest TIP
forecasts for longer predictions at individual locations
Link to DrJack's home