2009

It has been awhile since the last significant  update on Weather West because…well…very little has been going on weatherwise in the state. Wildfire activity has picked up notably across the state in recent days, and there are a number of notable fires in northern and central California at this time. Weather over the weekend will feature warmer and drier conditions with some offshore flow in the hills. This may contribute to fire growth, but probably won’t lead to rapid and dangerous fire spread. The week ahead looks to be a relatively hot one–with temperatures exceeding 100 in inland areas across the state. This is not especially unusual for mid-August, however, and is much more seasonable than some of the conditions experienced during the early part of the month. Forecast models indicate that a relatively warm regime will continue for the foreseeable future. There is some small potential for a monsoonal surge in the 7-10 day period, but given the paucity (absence, really) of such events thus far this summer I am rather skeptical at this time. Tropical cyclone activity in both the eastern Pacific and the Atlantic will be increasing over the coming week, and the flow pattern near CA will be moderately favorable for the advection of remnant tropical moisture northward. This potential will have to be watched over the next two weeks…and presents the highest probability of interesting weather for the rest of the month (though still not likely).

Weak El Nino conditions continue in the Pacific. The rate of increase of SST anomalies has slowed in recent weeks, but this temporary slowdown was actually indicated explicitly by the CFS model, followed by a resumption of SST anomaly increase by mid-September. The CFS is still calling for a strong El Nino event this winter, so I still think that a moderate to strong event is still likely to occur. Stay tuned…