LINKS TO THE LATEST BLIPSPOT FORECASTS
BLIPSPOT^™ = Boundary Layer Information Prediction SPOT
Created by Dr. John W. (Jack) Glendening 

Description:
    BLIPSPOTs predict thermal soaring conditions resulting from boundary layer heating by post-processing numerical weather predictions to provide parameters suited to the needs of soaring pilots.  BLIPSPOTs are processed as soon as forecast files are available and thus provide the "latest" predictions for a given location.  One intent of the BLIPSPOT is to help determine when conditions at a location removed from the launch site are worth taking a long tow to investigate.  A BLIPSPOT emphasizes temporal changes whereas a BLIPMAP depicts spatial variations but their parameters are essentially identical and are described on the BLIPMAP parameter webpage.  The most important parameter is either "Hcrit" for flat terrain or for non-flat terrain, which estimates the maximum thermalling height under cloudless conditions. 
    Relative differences are expected to be more reliable indicators of soaring variations than are the precise numerical values predicted.  The BLIPSPOT parameters are averages over 20km grid squares forecast by NOAA's Forecast Systems Laboratory RAP model.  BLIPSPOTs do not predict thermal lift created by small-scale terrain features which are not resolved by the model topography, which often give localized updrafts significantly stronger than those over the surrounding smoother terrain.  The BLIPSPOT thus indicates conditions over an area surrounding the specific feature used for naming purposes rather than immediately above the feature itself.
    Since the smoothed model topography differs from the actual topography, the surface height and temperature used for the BLIPSPOT are sometimes altered from those used by the model as an approximate adjustment for such differences or in an attempt to better predict conditions over a small-scale feature not included in the model topography.  The first elevation following the BLIPSPOT name is the surface elevation assumed by the BLIPSPOT and following that is the actual model grid point data, including its longitude, latitude, and surface elevation.  Any surface temperature adjustment used is noted in the header information - this is an ad hoc adjustment and may be altered if thermalling height/strength is consistently over/under that predicted by the BLIPSPOT.  Maps with location identifiers (BLIPSPOTs are magenta colored) and additional topography information are available at the Regional Grid Orientation webpage.
    Also provided on this webpage are links to the FSL interactive soundings located at the model grid point lat/long used for the BLIPSPOT (so its lat/long may therefore differ from airport or city lat/longs) - however, the FSL soundings are only available for a 40km-spaced subsample of the full 20km-resolution grid, so there a 75% probability that the profile viewed is not at the exact location used by the BLIPSPOT (the line immediately above the plot will then read "Xnm ... from ..." where X is not 0), and the values are also smoothed by averaging over the neighboring 40km-subsample points.  Another pitfall of use of this sounding data is that the lowest-height temperature displayed is that of the model's first grid level, not the "surface" temperature - since the former will alwyas be cooler than the latter on convective days, use of these sounding will somewhat underpredict the BL top.  Some information on interpreting such soundings is available at the Convective Boundary Layer and Sounding Analysis webpage.
    Other RUC forecast variables are available at the FSL RUC forecast products webpage and RUC soundings are available at the interactive (Java) FSL RUC sounding webpage..  Ideally 6hr forecasts are available every hour while 3hr,6hr,...18hr forecasts are available at 00Z,03Z,...21Z initialization/analysis times - however, the 20km FSL RUC forecasts are only semi-operational so results can be missing for various forecast times.

   Go to the BLIPMAP regional forecasts
   Go to pilot flight experiences using BLIPMAPs and BLIPSPOTs.
   Go to BLIPMAP Help webpage.
   Go to DrJack's home page