April 1, 2021 – Dry conditions with much above normal temperatures through Friday. Cooler, but still mild this weekend. Light precipitation may return early next week.
Upper level ridge over NorCal will flatten a bit over the next few days, with dry conditions, light winds and much above normal temperatures continuing.
High temperatures for Valley locations will warm to the mid and upper 80’s today, with slight warming at 850 mb versus yesterday. These readings are 15 to 20 degrees above normal for this time of year and could approach record levels at a few locations. Records are generally from 85 to 90 degrees today.
A series of disturbances passing through the Pacific Northwest will gradually lower heights Friday into the weekend, cooling the temperatures back into the low 80’s Friday then 70’s Sat/Sun, but these readings are still 5 to 10 degrees above normal.
Ensembles and clusters are in poor agreement with potential Pacific storm system approaching the West Coast late Sunday and Sunday night. Will use NBM guidance, which keeps low to medium pops going and light QPF values. Forecast confidence Sunday and Sunday night is low.
Extended discussion (Monday through Thursday)
Troughing will be setting up over the west for the start of the extended forecast. The trough will have two main areas of energy on Monday, one pushing into the PacNW and another digging over the Pacific. This will help to push a front into the region and will start to bring some light shower chances to the area.
Shower chances will continue into Tuesday and Wednesday as troughing continue over NorCal. We are seeing a wide variety of solutions in the ensembles on this trough and they do not have a good grasp on what is going to happen especially with timing but also with placement. This leads to very low confidence in the extended forecast.
Hopefully models will come together in the next day or two. With troughing over the region we can expect cooler temperature with them near to just below average.