Dry and mild with above average temperatures through Wednesday. Widespread showers and mountain snow possible Wednesday evening into Friday. Additional mountain snow showers possible Saturday.
Discussion
High pressure has shifted east a bit, but remains strong enough to keep the stalled frontal system well to our north. High clouds cover much of the area north of I-80 and current temps are considerably milder across most of the Sacramento Valley where readings are in the mid 40s to mid 50s. Onset of precipitation later this week continues to slow as the initial system trends toward splitting and digging offshore, definitely hinted by several of the ensemble clusters over the past few days.
So, the dry and mild weather pattern will continue another couple of days. Highs today will be similar to Monday’s, perhaps up a degree or two in some areas, and a few record highs may be in jeopardy (particularly KSAC with 74 from 1954 and KSCK with 75 from 1994).
Thicker clouds may bring a little cooling on Wednesday as the trough approaches. The weather pattern will become unsettled for the end of the week as several waves move through the trough.
Uncertainty remains in the timing and details of these waves, but at this point it’s looking like Thursday into Friday for the best chance of precip for most areas.
Snow levels will hold fairly high into Thursday before lowering to around 5-6k ft. Depending on how the system evolves, light to moderate snow may occur over the higher elevations through Friday night with perhaps a foot or so of snow at the higher pass levels over a 48 hour period. Travel impacts will be possible, and a Winter Weather Advisory may be needed.
For QPF its looking to be 0.50-1.50″ over the higher elevations with 0.25-0.50″ over the Valley. Sacramento tied its record yesterday for the number of consecutive dry days during the wet season with 52 days (old record 2013-2014). Rain Thursday means the new record will stop at 54 days.
Extended Discussion (Saturday through Tuesday)
Upper low progged to dig through CA Saturday although models differ on westward extent of this feature. For now, main threat of showers appears to be over the eastern foothills and mountains Saturday. Snow levels expected into the upper foothills.
Second weaker wave looks to follow Sunday with a slight chance of snow showers over higher terrain of the Sierra Nevada. EPAC upper ridge progged to build inland over interior NorCal early next week. This will result in dry weather with warmer temperatures and some locally gusty north to east wind.