California Annual Precipitation (CAP) Report
Innovative & Actionable Precipitation Forecasting
Weather Tool’s CAP report supports the long-range planning needs of industries that are dependent upon what happens during California’s wet season.
CAP forecasts have successfully verified EVERY year – 7 years in a row. No other California precipitation forecast has come close to doing the same.
The CAP Forecast Model
Until now, a reliable water year precipitation forecast for California has not existed. During the first week of November, CAP forecasts the total precipitation for California’s water year (Oct 1-Sept 30) – almost a full year in advance.
This statistical model provides two critical pieces of information:
- Whether it will be an “above” or “below” normal water year.
- A definitive range of precipitation amounts, in 20% ranges relative to normal: >40% below normal (BN), 20-40% BN, 0-20% BN, 0-20% above normal (AN), 20-40% AN, or >40% AN.
Once the data is analyzed and predictions are made for the water year, the forecast doesn’t change. Customers are not left chasing a fluctuating prediction and can make informed, water-related decisions months in advance.
Coverage Area
This domain includes the footprint covered by the California State Water Project and Central Valley Project contractors. The forecast output can be further regionalized to meet a customer’s specific operational needs.
In addition to the water year precipitation forecast, customers receive monthly progress reports with information on how the water year is unfolding. This includes an update on precipitation received utilizing National Weather Service data, a meteorological comparison with similar water years, inferences on precipitation patterns and timing, and reservoir status.
