Where to find information
Updated July 30, 2007
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For information on the Registration system, see:
Registration Information webpage
For information on Subscribing see:
Subscription Information webpage
If you experience problems displaying maps after registering:
User Problems section of Registration Information webpage
The following are suggested first steps in learning what BLIPMAPs are and how to use them:
A good "first thing to read" for potential BLIPMAP users, giving an
overview of BLIPMAP predictions, is the on-line version of the
July 2002 SOARING magazine BLIPMAP article
You must choose between two different forecast models, the NAM
or RAP (but if you want a forecast for tomorrow you must use
the NAM model), so go the the "BLIP Forecast Models
webpage", read their descriptions, and click one of the link to
get to that model's regional BLIPMAP forecasts.
Skim the sections and information on your regional BLIPMAP page
so you will know what is there for later reference.
Note that BLIPMAP plots available from links on this page are for
only a single time of day.
Read BASIC thermal forecast parameters -
a short and simple list of the parameters most important for thermal soaring
For daily forecasts, you will want to start with a few important parameters
and later employ additional parameters after gaining experience. The most important
parameter is likely either Hcrit (for flat terrain) or BL Top (for complex terrain).
You might add the "Cumulus Cloud Potential" prediction if it is expected to be important in your region.
Scanning the parameter descriptions will indicate what other predictions are also available.
Clicking on the "CurrentDay" (for NAM) or "Latest" (for RAP) link obtains the most recent prediction for a parameter.
What NEXT ?
The following will make one a more competent user:
Critically assess BLIPMAP predictions against conditions encountered in-flight
Utilize additional parameters - parameter descriptions on the
regional BLIPMAP webpage indicate what predictions are available and,
if needed, the related "MoreInfo" link leads to further details
about each parameter. Parameter descriptions can also be found
on the BLIPMAP
Read the "Description" section of the regional BLIPMAP page to better understand what is being presented.
Read the news ("DrJack sez") section of the regional BLIPMAP page for additional information and links.
If your site is at a
BLIPSPOT location, use that BLIPSPOT to see how the soaring is
forecast to change during the day at that location.
After gaining experience, forecasts for other hours during the day can
(see the link on an individual region's BLIPMAP page) or the new BLIPMAP
UniViewer. The latter has the advantage of allowing map
re-sizing but is more susceptible to errors resulting from incorrect
How one pilot uses BLIPMAPs for his XC soaring:
"BLIPMAPs for Idiots" Slides from a 2004 PASCO Soaring Seminar presentation, by
Ramy Yanetz (PDF - 42MB download)
How one pilot combines BLIPMAPs with other on-line weather
Using BLIPMAPs and other forecast tools by Harry Fox, Bay Area Soaring Associates.
To become an expert user one should read additional links given below, particularly the
notes and Frequently Asked Questions webpages.
For GENERAL INFORMATION
Some SPECIFIC ANSWERS
What are the differences between the NAM and RAP model forecasts ?
NAM vs RAP
What different forecast display pages are available ?
The traditional BLIPMAP plot display is the "index" page which
describes and provides links to BLIPMAP forecast variables for a
single time and region -
for the NAM model these are available for regions
and for the RAP at
Forecasts for multiple times using webpages
having a similar format can be obtained for the RAP model (only) at
viewers, which allow rapid switching between forecast plots.
The following viewers are intended for experienced BLIPMAP users and each has
different advantages so one's choice is based on one's personal
(3) "Regional" viewers
for the NAM model at
and for the RAP at
which can display forecasts for all regions for both models,
"2Viewer" which provides side-by-side comparison of two
different forecasts, e.g. RAP and NAM forecasts for the same
How can I get a "Skew-T" sounding plot?
viewers noted above. First the type of "sounding popup" desired
must be enabled using the "MapClick Popup" checkbox choices available
on the viewer sidebar - then a mouse click on the BLIPMAP will produce
a "popup window" displaying the sounding for that particular
latitude/longitude. [Note that several sounding choices are available -
soundings can be obtained from the GSD (old GSD) website which have interactive functionality
not available from my site's soundings. ]
Where can I obtain thermal soaring parameters at a single
location at different times for the current day ?
For certain sponsored locations, "BLIPSPOT" forecasts -- displaying
BLIPMAP parameters and wind profiles throughout the day for that
specific lat/long -- are freely available (after registration) - see
the RAP BLIPSPOT
webpage. Alternatively, registered users can click on
will produce a "miniBLIPSPOT" popup window which displays BLIPMAP
parameters throughout the day for that selected lat/lon [note that the
"MapClick Popup" miniBLIPSPOT checkbox choice available on the viewer
sidebar must have been checked].
How can I get today's "trigger temperature" ?
First understand that there is no such thing as the trigger
temperature! A "trigger temperature" is the temperature that the
air near the surface must reach to produce thermals to a
specified height (using assumptions about the relationship between
surface temperature and thermal height) - so the "trigger temperature"
depends upon the height of interest. For RAP model forecasts,
the "miniBLIPSPOT" popup window described in the previous answer
provides "trigger temperature" information for several different
thermal heights at any desired BLIPMAP location.
Where are specific locations located ? Are geographical or terrain maps available ?
Maps of geographical features (towns, roads, etc) and maps of model
terrain are available on the regional "index" webpages and on the
viewer pages. For the RAP model, a
RAP Grid Orientation Information webpage provides information on
regional maps of terrain, surface (vegetation) type, and "identified locations"
(but in complex topography note the warning on that page)
When are model predictions particularly likely to be in error:
Model prediction notes
Are alternative display formats available ?
In addition to the traditional BLIPMAP plot displays,
alternate graphical display formats are available using
BLIP data display software. And if you are willing to do
some work yourself you can create your own browser page exactly as
you like it, with images showing the model(s) and parameter(s) and
time(s) you select, side-by-side images, different image sizes, etc -
see the July 23, 2003 FAQ describing simple image pages and the April 6, 2004
FAQ describing local viewers in the Frequently Asked
What is the latest BLIPMAP forecast availability status ? [for both
RAP and NAM models]
For the CANV region use the URL
- for other regions,
replace CANV by NW, SW, GP, OKTX, NC, SC, NE, or SE
What are "typical" conditions ?
2002 RUC Climatology
How accurate are the "current+1" and "current+2" advance forecasts provided by the NAM model ?
Accuracy of NAM Advance Forecasts - Summer 2005
What is the best way to compare NAM and RAP model forecasts for a given day/time/parameter ?
Use the BLIPMAP
comparison "2 Viewer", which can simultaneously display NAM and RAP
forecasts on side-by-side panels.
How closely do the NAM and RAP model forecasts for different parameters agree/disagree ?
See the NAM-RAP
Monthly Difference Viewer
Can I obtain old BLIPMAP forcasts ?
An archive viewer is available at
NAM+RAP Archive Viewer
can plot both NAM and RAP model archives,
Are there special webpages for cell phone access ?
Darryl Ramm's iPhone/iPod webpage.
If you have difficulty reading text/color on an image, you should
check out the following tools: (1) For Windows users, a
"magnifier" is available under "Accessories" -> "Accessibility",
(2) For Firefox browser users, the "Image Zoom" extension can
be added to selectively increase the size of an entire image up to
400%, (3) There are also third-party magnifiers "Super
Magnify" for Windows users and "xzoom" for X11/Linux users.
What BLIPMAP/SPOT changes have occurred in 2004 ?
Summary of major BLIP changes for the 2004 soaring season
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