2009

Our very welcome wet and active pattern will continue for the foreseeable future. A minor precip event will occur in NorCal overnight tonight and into the day tomorrow, but there will very little weather of significance associated with this system. Our next real weather-maker is slated to arrive over the weekend, and this storm has the potential to be rather significant in NorCal. The models are not in ood aggreement as to the exact placement of low centers located within a complex larger gyre, and this complicates the forecast substantially. A surface low is expected to develop on a strong southerly jet just off the CA coast and deepen rapidly into a sub-980 mb low as it passes by CA to the northwest. The ECMWF is much closer to the coast with the low and therefore brings much heavier precip and stronger winds to CA. At this point it really is not clear which is the better scenario: the less dramatic GFS or the very intense storm depicted by the ECMWF. Either way, it will rain throughout most of the state by late in the weekend, and that rainfall could be very significant up north. This system will have a another deep tropical tap, at least initially, and so snow levels will be relatively high to start the event. As the cold front passes and secondary low approaches from the Gulf of Alaska early next week, expect precipitation to continue with lowering snow levels. Some convective activity is possible next week once the colder air aloft moves in, as well. The most recent GFS has another similar (but perhaps more southerly) cyclonic storm directly affecting the CA coast by day 7, and more systems down the pipeline behind that one.  Stay tuned for the weekend storm–but keep in mind that SoCal probably won’t see much beyond light showers until perhaps days 6/7.