2009

Much of CA saw thunderstorm activity today. Interestingly, the west side of the Central Valley was just about the only place that did not see any lightning activity today. A number of severe storms did develop today, mainly in the far northern part of the state (though there was one warned cell in the East Bay area) and there were some reports of large hail and damaging winds in the Trinity Alps. The upper low continues to spin nearly stationary off the coast, rotating occasional vorticity maxima across the state. Isolated to scattered showers and thunderstorms will accompany these disturbances through the overnight hours. Thursday may be less unstable than today but have more widespread convective coverage due to the presence of more trigger mechanisms and a closer proximity to the low center. Numerous mountain thunderstorms and scattered valley storms are expected tomorrow, and at least a few of these are likely to be severe once again, esp. mountain areas. The low begins to slowly weaken and move inland over central or northern CA on Friday, bringing the period of maximum instability to coastal regions. More scattered thunderstorms will be possible on Friday for much of the state. Isolated showers and thunderstorms may persist over the weekend, especially in mountain areas, as the low is slow to move out of the region.

SoCal did receive some unexpected shower and thunderstorm activity today. This was all high based and the result of significant dynamic instability. Though I don’t expect a repeat of today’s storms, it is possible that Los Angeles and San Diego could have a shot at  a few more storms before the low moves away this weekend.

One more item of note: the models are indicating at least a small chance that a new cutoff low will develop and bring more unsettled weather to the state next week. We shall see about that…it is June, after all…