April 25, 2017 – Weak weather systems will bring light precipitation through Wednesday. Gusty north winds develop late in the week.
Break in precip across interior NorCal early this morning as short-wave ridging from the eastern Pacific begins to build in. However, skies remain partly to mostly cloudy across the region as deep moisture continues to stream across the Pacific. Current temperatures are generally in the 30s in the mountains with 40s to lower 50s elsewhere – slightly cooler in most areas compared to 24 hours ago.
The next system will move into the PacNW today, however some showers will make it far south as the northern mountains and northern Coast Range. Another system will follow quickly on its heels spreading shower chances further south later tonight and Wednesday. Only light amounts of QPF are forecast and snow levels will rise to above 8K feet, so expect little or no impact to travel across the northern Sierra passes.
Stronger ridging from the eastern Pacific builds over the area bringing a return of dry weather along with warmer temperatures as highs are expected to return to close to average for late April. Breezy northerly winds will also develop across the region.
Extended discussion (Saturday through Tuesday)
High amplitude upper ridging in the EPAC extends over Interior NorCal through the weekend resulting in dry conditions with above normal temperatures. Breezy northerly winds from Friday continue into Saturday. Ridging weakens over northern portions of CA Monday as a short wave trough digs through the PACNW into the Great Basin. This will result in minor cooling over northern portions of the forecast area. High pressure rebuilds behind the wave Monday night into Tuesday resulting in a return of breezy northerly wind. Low level CAA with this flow will offset downslope warming and maintain slightly cooler temps of northern portions Tuesday.