Extratropical storm activities have strong societal and economic impacts on mid- and high-latitude regions, including Alaska. To support the NWS Alaska and other regional centers for storm track monitoring and forecast products, a suite of week-2 storm track forecast products has been developed at CPC based on the dynamical forecast of the NCEP Global Ensemble Forecast System (GEFS).

Extratropical storms are detected and tracked using 6-hourly sea level pressure (SLP) data from the real-time GEFS 16-day forecasts and a storm-tracking algorithm (Serreze 1995). The week-2 outlooks include storm tracks and track density, storm intensity and duration, precipitation, SLP and 10-m wind over North Pacific, North America, and North Atlantic, derived from the GEFS week-2 forecasts for both total and anomaly fields. In addition, GEFS week-2 probabilistic forecasts of precipitation and 10-m wind exceeding 75% and 90% percentiles, and storm intensity lower than 990, 980, 970, and 960 hPa are also included. Verifications for the real-time week-2 forecasts are conducted using the NCEP Climate Forecast System Reanalysis (CFSR). The week-2 storminess outlook is updated on a daily basis. More details about this tool are here.

June 2021

Sun	Mon	Tue	Wed	Thu	Fri	Sat
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20	21	22	23	24	25	26
27	28	29	30

Week-2 Products
>>> Regional maps for Alaska/Arctic, North Pacific, North America, North Atlantic
Storm tracks, track density, intensity, and duration
7-day precipitation, sea-level pressure, wind vector and wind speed
Starting from September 24, 2020, forecasts are GEFSv12 based.
GEFSv12: 124-member ensemble forecast