Datasets / Climate Prediction Center (CPC) One Month Probabilistic Precipitation Outlook for the Contiguous United States and Alaska


Climate Prediction Center (CPC) One Month Probabilistic Precipitation Outlook for the Contiguous United States and Alaska

Published By National Oceanic and Atmospheric Administration, Department of Commerce

Issued over 9 years ago

US
beta

Summary

Type of release
ongoing release of a series of related datasets

Data Licence
Not Applicable

Content Licence
Creative Commons CCZero

Verification
automatically awarded

Description

The Climate Prediction Center (CPC) issues a probabilistic one-month precipitation outlook for the United States twice a month. CPC issues an initial monthly outlook with a lead time of 0.5 months on the third Thursday of every month. CPC issues an updated version of the monthly outlook with a lead time of 0.0 months on the last day of each month. For example, in mid-January, CPC will issue a One-Month Probabilistic Precipitation Outlook for February. An updated version of this outlook (valid for February) would then be issued at the end of January. New outlooks, valid for March, would then be released in mid-February and the end of February, respectively. CPC expresses the outlooks in a 3-category probabilistic format as the chance the total precipitation for the period will be above, below, or near median. CPC bases its definition of above median, near median, and below median by fitting a Gamma distribution to a thirty year climatology and dividing this distribution into equally likely thirds. Note that the base period for the thirty year climatology (currently beginning in 1981 and ending in 2010) is updated once per decade. CPC indicates the probability of the most likely category with shaded contours and labels the centers of maximum probability with the letters "A" (for Above Median), "B" (for Below Median), or "N" (for Near Median). For areas where a favored category cannot be determined, CPC indicates those areas with an "EC" meaning "Equal Chances". CPC also accompanies the outlook maps with a technical discussion of the meteorological and climatological basis for the outlooks. CPC may include analysis of statistical and numerical models, meteorological and sea-surface temperature patterns, trends and past analogs, and confidence factors in this technical discussion.