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 ways:
    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 triangle flights).

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 started forming!


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 good ones.

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 good results.

Here is a brief rundown of the tools he has created, and how we use them...



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 of forecasting.



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.

DrJack comments:
    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 page