Monday, 14 January 2002
Comparison of MM5 convective precipitation forecasts with cloud-to-ground lightning information in the CONUS Intermountain West
In order to determine if the 5th generation Mesoscale Model (MM5) forecast of convective precipitation is valid, we compared the measured cloud-to-ground (CG) lightning data from the National Lightning Detection Network (NLDN) with the results of MM5 model forecasts in the Intermountain West region of the United States. The goal was to attempt to validate the modelís ability to forecast the occurrence of convective precipitation by comparing the regions where this precipitation was forecasted to occur and the actual occurrence of CG lightning. The absence of CG lightning does not imply that there was no convective precipitation in the area since the lightning may have never reached the ground, but the presence of CG lightning should indicate that convective precipitation occurred. Our study attempts to show the presence of model forecasted convective precipitation when and where CG lightning occurred for various case study days. In cases of disagreement between the model result and measured data, overall characteristics of the weather patterns were taken into account to try and determine if trends exist which hinder the modelís ability to forecast this type of event.