And Here It Comes, This Afternoon!

I was baffled why weather reports over the weekend kept reassuring people the worst is over. The worst just arrived.

Steady soaking rains will intensify this evening, possibly culminating in a very intense burst of precipitation at some point tonight as the strong and fairly convective cold front passes through. This steady ramp-up of precipitation intensity, followed by a final burst of rain rates possibly approaching 1 inch/hour, will likely lead to widespread flooding given already wet antecedent conditions. In some parts of the Bay Area, Sacramento Valley, and Sierra Nevada foothills, life-threatening flash flooding of streams and smaller rivers could result. In addition, larger rivers from the Santa Cruz Mountains northward to the Mendocino coast may respond rapidly to this additional rainfall, possibly leading to the highest flood levels in years. The Sacramento River will reach its highest level in at least a decade, flooding the Yolo Bypass. Large and dangerous mudslides have already started to occur in many places, and this risk will remain very high for at least the next 24-48 hours in areas of steeper terrain and near recent wildfire burn scars.