Rainy Season Begins?
It's September 12. The traditional rainy season in Southern California usually begins next month (and even then, not in full force until November). But 2015-16 is no "usual" year. With a massive (and now, officially, "strong") El Niño brewing in the Pacific, many forecasters are holding out hope that this winter will deliver pounding rains to California.
Well, this week is likely to give us a brief taste of that. While still uncertain whether we will actually get any rain, the models are trending toward a somewhat wet solution for today through Tuesday as the remnants of Hurricane Linda get swept up in an autumn frontal system that will sweep southward beginning tomorrow and lasting through Wednesday. At a bare minimum, a huge cooldown is coming: Temperatures for Wednesday are forecast to be in the low to mid 70s!!
Already today on the radar we see a few showers generating along the eastern edge of what used to be Hurricane Linda (see the image)
But, more importantly, the higher resolution NAM (WRF) model is forecasting the leftover remnants of Linda to get sucked up into a trough of colder air that is dropping down now from the Gulf of Alaska. This could bring us off and on showers sometime Monday into Tuesday (the timing is still uncertain). Here is an image of the NAM-forecast for 4am on Tuesday showing Relative Humidity at low levels (850mb). The bright whites and light blues indicate clouds and, possibly, precipitation. The arrows are wind streamlines showing a big trough digging off our coast to the west: