CAP model output indicates that Region 4 will receive 92.5-112.5% of normal precipitation. For Region 4, 92.5-112.5% of normal equates to 36.94-44.93”.

The regional gauge below shows the CAP forecast lower and upper bounds (36.94-44.93”), the “normal” for Region 4, and the observed precipitation through the end of December.  With another boost from the recent atmospheric river activity, this region recorded an impressive 6.5 inches of accumulation in December and sits just shy of 40% of total water year precipitation, marking an increase of approximately 17 percentage points in a single month.

Region 4 has typically received 12.17 inches by this point in the water year; with 15.8 inches currently recorded, the region is running well above average.

The NWS data feed we typically use for verification has been permanently discontinued due to federal funding issues so we have made some adjustments to our verification framework. Estimates for water year averages are calculated using station data from the regional precipitation indices produced by the California-Nevada River Forecast Center (CNRFC): the 8 stations comprising the Northern Sierra represent our CAP Region 2, the 5 stations of the San Joaquin Basin represent our CAP Region 4, and the 6 stations of the Tulare Basin represent our CAP Region 6.