After an unusually (record-breaking, actually) cool and cloud period in Southern California over the past couple of weeks, more seasonable conditions are rapidly returning. A weak upper-level low off the CA coast has led to moderately strong southeasterly flow across the state, bringing in warmer and moister air and acting to suppress the very tenacious marine layer that has persisted for quite some time. Up north, temperatures have remained quite warm to hot through the period, and they’re only going to get worse moving forward. Mid and upper-level monsoonal moisture has begun to move into the state, and afternoon thunderstorms have been pretty impressive over the Sierras for the past several days. Storms may also begin to fire along the higher terrain of Southern California beginning this weekend and continuing on and off for the foreseeable future. Over the next three or four days, there is also a smaller chance of some high-based convection over other areas. There is actually a considerable amount of moisture over the region; there just isn’t much instability present. A weak easterly wave, though, could provide just that. So…as with most monsoonal surges…this one will most probably be felt in the mountains and deserts, with a small possibility of activity elsewhere. Temperatures will continue to increase into next week, possibly to well above seasonal norms. Mid-level flow will continue to be favorable to advect monsoonal moisture into Ca, ad we’ll have to keep an eye on the tropical E. Pacific, as well, since a persistent southerly flow will be present. All in all…typical July weather.
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