Average dry thermal updraft strength near mid-BL height.  Subtract glider descent rate to get average vario reading for cloudless thermals.  Updraft strengths will be stronger than this forecast if convective clouds are present, since cloud condensation adds buoyancy aloft (i.e. this negects "cloudsuck").  W* depends upon both the surface heating and the BL depth.  MoreInfo

The temperature at a height of 2m above ground level.  This can be compared to observed surface temperatures as an indication of model simulation accuracy; e.g. if observed surface temperatures are significantly below those forecast, then soaring conditions will be poorer than forecast.  This parameter is obtained directly from WRF model output and not from a BLIPMAP computation

Combining the previous two parameters, this depicts the Cumulus Cloudbase only at locations where the Cumulus Potential parameter is positive.  This single plot can be used, instead of needing to look at both the Cumulus Potential and Cumulus Cloudbase plots, if the threshold Cumulus Potential empirically determined for your site approximately equals the theoretical value of zero.  For locations where the actual threshold is greater than zero, as is often the case, this depiction will over-estimate the extent of the cumulus region. 

This parameter provides an additional means of evaluating the formation of clouds within the BL and might be used either in conjunction with or instead of the other cloud prediction parameters.  It assumes a very simple relationship between cloud cover percentage and the maximum relative humidity within the BL.  The cloud base height is not predicted, but is expected to be below the BL Top height.  DrJack does not have a lot of faith in this prediction, since the formula used is so simple, and expects its predictions to be very approximate - but other meteorologists have used it and it is better than nothing.  Note: Since The the "BL Cloud Cover", "Cumulus Potential", and "BL Extensive CloudBase" are based upon fundamentally different model predictions -- respectively the predicted maximum moisture in the BL, the predicted surface moisture, and an explicit cloud-water prediction -- they can yield somewhat differing predictions, e.g. the "Cumulus Potential" can predict puffy cloud formation when the "BL Cloud Cover" is zero or vice versa.

Depth of the layer mixed by thermals or (vertical) wind shear.  This parameter can be useful in determining which flight direction allows better thermalling conditions when average surface elevations vary greatly in differing directions.  (But the same cautions mentioned under "Height of BL Top" also apply.)  It is also an important determinant of thermals strength (as is the Surface Heating).  MoreInfo

Height of the top of the mixing layer, which for thermal convection is the average top of a dry thermal.  Over flat terrain, maximum thermalling heights will be lower due to the glider descent rate and other factors.  In the presence of clouds (which release additional buoyancy aloft, creating "cloudsuck") the updraft top will be above this forecast, but the maximum thermalling height will then be limited by the cloud base (see the "Cloud prediction parameters" section below).  Further, when the mixing results from shear turbulence rather than thermal mixing this parameter is not useful for glider flying.  NB: this BL Top is not the height where the "Thermal Index" (TI) is zero, which is a criteria used by many simple determinations of the BL top - instead, the RASP BL Top uses a more sophisticated BL Top criteria based on turbulent fluxes.  MoreInfo

This parameter estimates the height at which the average dry updraft strength drops below 225 fpm and is expected to give better quantitative numbers for the maximum cloudless thermalling height than the BL Top height given above, especially when mixing results from vertical wind shear rather than thermals.  (Note: the present assumptions tend to underpredict the max. thermalling height for dry consitions.) In the presence of clouds the maximum thermalling height may instead be limited by the cloud base (see the "Cloud prediction parameters" section below).  Being for "dry" thermals, this parameter omits the effect of "cloudsuck".  MoreInfo