The Beta and Advection Model (BAM), follows a trajectory in the pressure-weighted vertically-averaged horizontal wind from the Aviation model beginning at the current storm location, with a correction that accounts for the beta effect (Marks 1992). Three versions of this model, one with a shallow-layer (BAMS), one with a medium-layer (BAMM), and one with a deep-layer (BAMD), are run. BAMS runs using the 850-700 mb layer,BAMM with the 850-400 mb layer, and BAMD with the 850-200 mb layer. The deep-layer version was run operationally for primary synoptic times in 1989; all three versions have been run four times per day since 1990.
How often are they right?
susie
Thanks for the explanation from a hurricane nut in snow country.
mc