AR Category Forecasts

The dots on the maps below represent the AR Category analysis and forecast from the Global Ensemble Forecast System (GEFS) at each grid point. The left map represents the AR Category over the previous 7 days from the 0-hour analysis of the GEFS control member. The right map represents the AR Category forecasted over the next 7 days from the ensemble mean of the GEFS. The AR Cat is determined based on the duration of AR conditions and maximum IVT during the AR as described in Ralph et al. 2019 .

Analysis

Forecast:  



The plume diagrams below represent the integrated water vapor transport (IVT) and AR Category analysis and forecast from the Global Ensemble Forecast System (GEFS). The left side of each plot represents the 0-hour analysis of the GEFS control member for the previous 7 days. The right side of each plot represents each of the 20 perturbed GFS ensemble models (thin gray lines), the unperturbed GFS control forecast (black line), the 20-member ensemble mean (green line), and the maximum ensemble value at that forecast hour (red line) and minimum ensemble value at that forecast hour (blue line). The white shading represents the +/- 1 standard deviation forecast from the ensemble mean. Colored shading represents the AR Category observed or forecast for the given time, shaded according to scale, calculated using the GEFS ensemble mean. At the top of each AR Cat the maximum IVT during the AR (kg m-1 s-1), the AR duration (hours), and time integrated IVT (107 kg m-1) during the AR are shown. Note that if an AR is currently being observed at the given location (AR Cat shading over the center line), the AR Cat is calculated using a combination of analysis and forecast data. The plot on the left shows where each identified AR falls on the AR Scale matrix and how the category is calculated, represents an AR in the analysis period and X represents a forecasted AR.

AR Cat Calculated by:  

Location: