A quick update this evening. Strong thunderstorms continue to fire along the crest of the Sierras this evening, drifting west and weakening over the foothills. Much of the debris cloudiness from this convection is moving westward over the Central Valley and towards the coast. Based on visible satellite and radar imagery, some of these mid and upper level remnants are maintaining some sprinkles or at least virga as they move into the Valley. I would expect this to die out after the thunderstorms collapse after sunset. A similar/potentially even more widespread thunderstorm outbreak (including the Coastal Range in addition to the Sierras) could occur tomorrow and on subsequent afternoons through Saturday. All this activity is occurring ahead of a cut-off low currently 800-1000 miles SW of CA. Currently, southerly (SEly) flow on the east side of the low is creating just enough lift for storms to develop over elevated terrain. A quick look at the low still near the subtropics shows a visible moisture tap, and as this low lifts NEward over the next three days and crosses the coast, there is at least a small chance that some high-based convective activity could surprise us just about anywhere in the state. It’s not a likely scenario, but does remain a possibility. These types of weak and moisture-starved lows do have a propensity to generate dry thunderstorm activity even in the absense of particularly favorable conditions, so the skies may bear watching over the next 3-4 days (though don’t count on it). Nothing else to speak of through day 16 of the GFS model run.
