Determination of pollen concentrations via mesoscale numerical models and trajectory models is extremely sensitive to structure of the boundary layer. None of the available mesoscale models explicitly describes the structure of the Planetary Boundary Layer (PBL) and as such, parameterization schemes are necessary. Which PBL scheme produces the best pollen concentration forecast may not be the best modeling at the boundary layer. Several planetary boundary layer parameterization schemes are tested to determine which produces the best correlation to measured pollen concentrations. The National Center for Atmospheric Research’s (NCAR) MM5 model was run varying the PBL scheme. Using the forecasts from MM5, Hysplit_4 was used to generate pollen forecasts. The pollen forecast from each PBL scheme was compared to measured concentrations and these forecasts were then used to determine which PBL should be used to produce high spatial and temporal resolution pollen concentration forecasts. These pollen concentration forecasts are important to allergy suffers, since pollen is the greatest cause of seasonal allergic rhinitis (hay fever). These forecasts can be used by medical personnel to treat the allergy symptoms more effectively and to allow allergy sufferers to take preventative measures.