The Hydrometeorological Prediction Center's (HPC) experimental Alaska Medium Range forecasts are part of a National Centers for Environmental Prediction (NCEP) commitment to providing meteorological support for areas outside of the contiguous U.S. (OCONUS). Thus, the experimental Alaska Medium Range product suite is being developed to mimic that which is currently available for the CONUS. Differences between the product suites are primarily the result of addressing problems specific to the National Weather Service Alaska Region (e.g., highly varied terrain).

Currently, the experimental Alaska Medium Range product suite consists of surface fronts and pressures graphics valid at 1200 UTC on forecast days 4-8 and an Alaska Medium Range Discussion. Since these products are not yet operational, they may not always update in a timely fashion. It is anticipated that a more complete product suite will become available by spring 2008.

Each of the grids will be available downscaled to 5-km horizontal resolution.

One meteorologist is intended to be dedicated to Alaska Medium Range forecasting each day, and the shift is scheduled from 1300 UTC to 2200 UTC. The Alaska forecaster utilizes data from recent deterministic and ensemble model output and collaborates with the CONUS Medium Range forecaster before beginning graphical composition. This collaboration is important because the Alaska Medium Range Fronts and Pressures graphics must be merged with the final CONUS Medium Range Fronts and Pressures graphics for consistency. Deterministic and ensemble model output available to forecasters at NCEP/HPC include the GFS, Global Ensemble Forecast System (GEFS), Canadian GEM Global, Canadian GEM Ensembles, ECMWF, ECMWF Ensembles, Navy NOGAPS, UKMET, and the North American Ensemble Forecast System (NAEFS).

The experimental Alaska Medium Range Discussion is intended to complement the graphical products by outlining the model forecast preference, communicating forecast confidence, conveying areas of uncertainty and providing a catalyst for collaboration between HPC and NWS Alaska Region Weather Forecast Offices (WFOs).

While the 10th and 90th percentile Maximum/Minimum Temperature and Wind Speed forecast tools are still being developed, they are expected to use output from the NAEFS to generate a range of meteorologically possible values. The Alaska forecaster will choose the most likely scenario, while the spread of the NAEFS ensemble will determine the range of possible values for the forecast. This process will provide users both a sense of confidence from the ensemble members and a range of forecast possibilities, assuming favorable verification during testing.