Wednesday 10/20 6:30 am
The models are continuing to show a series of large storms hitting the Pacific Coast over the next week. Initially, these storms will trigger scattered showers from Washington down to Northern California beginning today. The largest of these storms will drop further south starting Sunday and deposit heavy rain and snow across Central California and the Sierra.
The good news is this will end the wildfire season. It will also be a huge boost to the reservoirs around the state. The bad news, mudslides across the fresh burn scars. Some of the people I follow out there are saying this could be a historic event and break the October 2004 record of 85.6 inches of snow for Mammoth Mountain.
If you missed my post yesterday, these types of events don’t translate to heavy precipitation for us. That being said we usually fare slightly better than the latest model runs are showing.
Here are the latest precipitation forecasts for the western US.
Euro
GFS
Canadian
Here are the state views
Euro
GFS
Canadian
If you remember the Canadian run from yesterday it was much different.
Canadian 24 hours ago
That is a good example of the model run roller coaster we will be on over the coming days.
When there is this much model uncertainty I am drawn to the more practical weather approach of looking at the ensemble families of the underlying models. These models take the average of all of the model members that make up the model family. I rely on them more several days before a storm. The good news or bad news with the ensembles is that they do not fluctuate as much on a run-to-run basis. I usually switch back over to the deterministic (single model) runs a couple of days before the storm arrives.
Here are the latest ensemble model precipitation totals
Euro
GFS
Canadian
There is one other trend I am seeing. The models are starting to introduce some light showers over northern portions of the forecast area on Sunday. So far they look insignificant. We’ll see.
My next update will be Thursday, thanks for following and supporting the site!