All RASP models here are based on the NWS NCEP North American Model (NAM) output. Using a reanalysis and plotting system devised by Dr. Jack Glendenning ,
the model is reanalyzed three times daily and sometimes a partial run during the day in the summer when days are long. The local RASP is run when the NECP data become available.
Their model runs are at 00z 06z 12z and 18z. That data becomes available approximately 1.33hrs after the zulu start time.
Re-analysis takes the 12km output of NAM and takes it to 4km for the "big picture" PNW domain and 1.3km resolution for the Tiger, Blanchard, and Fraser Valley domains.
ASP PNW is always run first when new data are available. BLANCHARD is actually the 1.3km resolution domain of PNW.
In the evening only, to provide the earliest possible windgrams and blipspots, all windgrams and blipspots are run from the 4km domain when it is finished.
These are replaced by the 1.3km resolution versions after each subregion has run.
RASP runs are rotated for the FRASER and TIGER regions so that if there was not enough time to finish them all during a particular 6 hour data cycle, there will be at least one run available by the next morning.
New data are made available on a 6 hour cycle for runs at 00 06 12 and 18GMT. The first 4km run is usually done by Runtime+3 hours. (around 8PDT 7PST)
The 1.3 km runs then require about an hour each so that if the run is particuraly complex or the internet is particularly slow, the last region often does not run before new data are available and is skipped until the next cycle.
In the summer when days are long there may be a run is done for 18z for the PNW and PNW-WINDOW domains only. Many parameters are not included so that it can finish more quickly and be available by about 2PM PDT.
New Blipspots and windgrams are generated at that time.
I developed the windgrams based on two common forms of display often called meteograms or time-height plots.
None of the examples that I could find displayed the
things that were most relevant to foot-launch soaring or to soaring in general. Dr. Jack Glendenning's RASP
all the relevant variables and his Blipspots™ are a numerical snapshot of a geographic point for the a number of hours.
seem to respond better to a graphical presentation than to a table of numbers. Hence, I developed the Windgram .
They are now in use by RASP operators in many parts of the world. I hope you find them useful. You can find an explanation of how to read the windgrams here.
In case you are thinking of running your own RASP system, this one is being run on a 4cpu 2.4GHz ASUS based system runing Fedora Linux. Other RASP operators use different flavors of Linux and at least one is running RASP in a virutal Linux machine under Windows. Most of the source code is available under the Gnu Copy Left rules.
The RASP system, developed by Dr. Jack Glendenning is a set of scripts written by DrJack that rely on the WRF model and software . The scripts download the data from government sources, prepare them for analysis by wrf, keep track of all the output, and finally run the output through the plotting scripts written in NCL. In addition to standard weather forecast features like wind speed and direction, DrJack has developed several other forecast indicies particularly useful to the soaring pilot. Among these are estimates of the maximum thermal strength, estimates of how high thermals will go and still be strong enough to lift a glider, and estimates of the tendency for thermals to be "shredded" by the winds. Not every parameter is useful every day, nor are they all useful for every site.
This particular RASP installation uses data from the National Weather Service NAM (North American Model) runs as input for additional high resolution analysis.
The plotting of the data into BLIPmaps and Soundings is done using Dr. Jack's NCL scripts. The whole system also relies on having a considerable amount of topographic and land use data which DrJack has packaged for easy deployment on an operator's system. In spite of all the things that DrJack has done, setting up and running the system is still a non-trivial exercise. A forum of operators, hosted at DrJack's site, help each other work through the difficulties they encounter.
The windgram plots were developed by TJ Olney and the script to create them is available to interested parties and is now in use by RASP operators around the world.
More information about the RASP system is available on Dr. Jack's site where you will find a list of running RASP systems as well as all you need to know to set up your own.
Fly Safe! TJ Olney