During the past few days, with little rain and active drainage of water, the dam level has been reduced substantially (see image)
But that is the ensemble mean or average. But there is a chance it could be more, so here is the ensemble maximum, the ensemble member with the highest amount of precipitation. Much more (30-50% more in some locations)..and a serious problem for Oroville Dam.
The 48h precipitation total ending 4 AM Tuesday from the GFS model projects 5-10 inches in the mountains.
And the European Center model has the same idea, with 5-7 inches
Looking at the NCEP SREF ensemble system at Blue Canyon, about 15 miles away from the dam, shows an ensemble mean of 7 inches, with a range from 5.5 to 13 inches. Great confidence for a major rain event.
Hydrological forecasts by the National Weather Service, project a rapid rise of the Feather River, the main feed into the reservoir behind the dam, with the flow quadrupling from around 7.5 thousand cubic feet per second to around 32 thousand.
This is a dangerous situation and, as always, there is uncertainty with our forecasts. Why is there so little discussion of the rapidly increasing precipitation?
And if you want to read an interesting blog about an unusually strong cold front that hit Hawaii, check this out: