Application of Sea-Level Pressure and Wind Speeds Climatology in Marine Weather Forecast Operations

A forty year climatology of global, oceanic characteristics was studied and compiled using the Climate Forecast System Reanalysis (CFSR). These parameters include both pressure, reduced to mean sea level (PRMSL) and wind speed (WIND). The study spans the globe using a 0.25 degree resolution of each parameter at the equator and 0.5 degrees beyond the tropics. The CFSR combines all forty years of data every six hours. WIND was found by combining the U and V components, focusing on magnitude only. For each investigated parameter, averages, standard deviations, maximums and minimums were calculated and plotted using python programming techniques. The latter two are used to express the vast range between the lowest and highest recorded PRMSL/WIND for the specified time.

The averages and standard deviations are used to identify an abnormal condition, such as rapid and explosive cyclogenesis or an anomalous pressure or wind speed event, to help Ocean Prediction Center forecasters quantify a cyclone as compared to climatology and to prioritize their attention. The figures produced by this program clearly show the regions most susceptible to variability in PRMSL and WIND patterns. Additionally, the methodology normalizes the anomaly, and imports and displays the current GFS run sequentially with the corresponding climatology data out to 96 hours. Initial results demonstrate this effort has been successful in introducing an operational capability to the Ocean Prediction Center. Displays of such capability will be demonstrated and further steps will be discussed.