Effective with the 0000 UTC cycle on October 1, 2002, MDL will implement a new system of AVN MOS Probability of Precipitation (PoP) and Quantitative Precipitation Forecast (QPF) guidance for Hawaii. Equations in this new forecast system have been developed to enhance the representation of local climatic effects in the MOS forecasts and to improve apparent shortcomings in the forecasts at Lihue (PHLI) and Kona (PHKO). In order to accomplish this, stations in the new PoP/QPF system were grouped so as to develop two sets of regionalized operator equations in place of the original single set of equations valid for all of Hawaii. The new forecast regions were chosen to differentiate among stations which have a high climatic relative frequency of precipitation and those stations which are drier due to their locations with respect to high terrain and the prevailing winds. We also have enlarged the developmental data sample by including data which were not yet available at the time the original AVN MOS system was developed, namely observations from three additional sites and a complete complement of model and predictand data from the 2001-2002 cool season.
For a complete summary of the AVN MOS products, including graphical displays of the probabilities, please view the: MOS Forecast Products Page