April 17, 2018 – Dry weather today. Pacific storm brings a chance of showers again Wednesday into Thursday with dry conditions Friday.
Skies have cleared out for the most part across interior NorCal as the low shifts east. There are some lingering clouds and some patches of fog in the Central Valley. Current temperatures are chillier compared to 24 hours ago and range from the teens in the mountain valleys to the mid 30s to lower 40s across the Central Valley.
Drier weather today as short-wave ridging moves into NorCal. Highs warm back into the 60s for the Central Valley, but remain well below average for mid-April.
Next frontal system approaches Wednesday with GFS/EC similar in digging the upper low southeastward along the CA coast through Wednesday night before shifting it inland over SoCal Thursday. Given storm track and limited moisture, best chances for precip will be along the western and southern edges of our forecast area.
Some showers forecast to linger over the Sierra south of Tahoe into Thursday evening, but the overall trend will be for warmer and drier weather late in the week with breezy north winds through the Central Valley.
Extended discussion (Saturday through Tuesday)
High pressure aloft will bring dry conditions over the weekend. Weak disturbances will flatten the ridge somewhat bringing some high cloudiness to the region Saturday and Sunday but daytime high temperatures will remain well above normal. Both GFS and ECMWF bring a relatively weak shortwave through norcal on Monday but differ on the timing. Each indicates some local light precipitation but given the weakness of this disturbance and model uncertainty, have kept the Monday forecast dry with just a slight cool off. Have kept Tuesday dry as well for similar reasons of model uncertainty. Despite continued cooler daytime temperatures, daytime highs Tuesday should still remain several degrees above normal.