October 18, 2016 – Drier weather returns to NorCal this week as the storm track shifts north of the region.
Discussion
Showers are beginning to move into far northern California early this morning as the next short-wave moves onshore. Showers will diminish across the north later today as the storm track retreats northward. Elsewhere, with generally light winds many locations are nearing saturation and some patchy morning fog will be possible.
High pressure will build through the remainder of the week resulting in warmer daytime temps and cool overnight lows as the airmass gradually dries. Locally breezy north winds will be possible at times.
Extended discussion (Saturday through Tuesday)
NorCal lies between a waning downstream ridge and an approaching upstream trough over the weekend. This synoptic pattern will provide a few degrees of cooling over the weekend and into next week, and bring some increasing cloudiness.
By Sunday night, both the GFS and ECMWF show a trough just off the west coast. The ECMWF rotates a more pronounced negative-tilt wave through our area Sunday night into Monday while the GFS has a less dynamic wave.
Either way, a persistent longwave trough remains near the west coast into early next week. Therefore, we introduced a chance of showers Sunday night/Monday into Tuesday. Beyond this, a wave moving into the parent trough appears to deepen into a cutoff low west of 130W. Depending on the longitudinal position, this could put us in a unsettled weather pattern.