BLIPMAP = Boundary Layer Information Prediction MAP
Created by Dr. John W. (Jack) Glendening, Meteorologist 

BLIPMAPs give thermal soaring parameters over a geographic region.

DrJack sez:
Welcome to the expanded BLIPMAP predictions, now providing two different model forecasts! 

This page is primarily for new users, since regular users will create bookmarks to lead them directly to the forecast region and model of interest to them.  Here you choose between the two model forecast types available, NAM or RAP - clicking on the top link in each column will lead you that model's regional coverage areas. 

NAM and RAP are two different models run by NOAA's NCEP (National Center for Environmental Prediction) and intended for slightly different purposes.  BLIPMAPs post-process the output from each to forecast parameters which are more useful to gliding pilots than the standard meteorological parameters. 

The principal differences between the models are given below, the most salient being that if you are looking for a forecast for other than the "current day" then you must choose the NAM model.  Although the models use the same basic methodology there are differences, notably in the simplifications used when processes are too complex to be treated exactly, so differences between the NAM and RAP forecasts do occur.  This is acerbated by the sensitivity of such models to uncertainties in our knowledge of the full 3D state of the atmosphere at any time. 



Click here for
NAM forecasts

Click here for
RAP forecasts


Forecasts out to 84 hours

Available only for two hours each day

Updated at 6 hr intervals

For same forecast period,
NAM available ~1hr later

12 km horizontal resolution

Poorer vertical BL resolution


Forecasts out to 12 hours

Available for five hours through day

Updated at 3 hr intervals

For same forecast period,
RAP available ~1hr earlier

20 km horizontal resolution

Better vertical BL resolution

Numerous model differences of detail, such as their parameterization of clouds, may lead to one model providing better forecasts of certain soaring parameters for your location, but that can only be determined through actual flight experience.

A more detailed description of differences between the two models is provided in the NAM vs RAP Model Comparison webpage

Usage information is available on the BLIPMAP information webpage