Blocking reigns supreme; no rain in sight.

Just a quick update this evening. Well, now even the minimal chance of rain for SoCal has all but evaporated. That low looks impressive on satellite, but the ground truth confirms that there just isn’t anything associated with it. Tropical moisture is not expected to be entrained by southerly flow on the east side of the low, so SoCal almost certainly won’t see any rain out of this. NorCal will continue to experience some foggy (and even becoming locally frosty) mornings, but nothing of particular note. The current scenario–of a powerful ridge in the mid-Pacific that acts as a Rex blockign agent for the mean flow, will prove very stable indeed over the next 2 weeks, according to the latest model output (and, interestingly, a secondĀ  reinforcing block will develop in the West Pacific). These patterns end in one of two ways: an undercutting of the block by a breakthrough of the East Asian jet, or when the block is forced westward to disintegrate in the westerlies by a retrogressive trough from Canada and the Gulf of Alaska. The GFS currently shows a sort of hybrid-type scenario, which is not a very strong indicator of anything. The models keep pushing back the date of the pattern change, and these patterns tend to be more persistent that even the models forecast. Therefore, it is possible that virtually the entire state will experience a completely dry December. There is still plenty of time to go, and it is indeed possible that the Westerlies will break through of that we will getsome cold storms from the north. Right now, though, this actually looks like a stronger and more persistent version of last year’s early winter rainfall pattern…that is: no rain.

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