Yesterday’s monsoonal incursion into Northern California did manage to bring localized light shower activity. Lightning was reported along the Napa/Yolo County line (upwards of 500 strikes) and in the northern Sacramento Valley (along with a few isolated strikes in the northwestern interior). A number of wildfires/brushfires were started by these mostly dry strikes, but nearly all have now been contained. San Francisco set a new daily record for rainfall on August 5th with–you guessed it–0.01 inch. Local very light showers ( now mostly virga) and a few lightning strikes continue in NorCal this evening, but outside of the mountains this should be over by tomorrow.
The long range is currently looking more interesting than it has in a while. The GFS and the ECMWF both develop a significant cut-off low somewhere over CA in the 6-10 day period. Depending on the depth of the low and especially on its placement–we could be in for a period of interesting weather for CA. If the low is sufficiently deep and set up shop off the coast of CA, excessive amounts of subtropical moisture will be drawn into the state from the SE sparking numerous showers and thundestorms. If we can get an E Pac tropical system thrown in the mix by days 4/5, things will get even more intersting. Of couse, if the low forms directly over the state, precip will likely be limited to the Sierras in the form of isolated afternoon thunderstorms, though a summer “Santa Ana”-type event could also occur, generating enormous fire weather concerns. This is certainly worth keeping an eye on…
