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August 12, 2016 – Dry weather with continued warming today and Saturday. Continued dry with above normal temperatures through next week except slight chance of northern Sierra thunderstorms Thursday.
Discussion (Today through Monday)
Upper level high pressure ridge over the eastern Pacific and west coast bringing fair skies to the CWA again this morning. Daytime high temperatures came in a few to several degrees warmer on Thursday and this trend has continued into the early morning hours today. Upper ridge axis is forecast to shift to near the west coast today bringing a few degrees more warming. Marine layer and expected delta breeze about the same as yesterday morning so expect a little warming delta areas as well. May see a little patchy stratus in the western delta this morning but this is about it. Should see a bit more warming on Saturday as the upper ridge pushes in across the west coast. Models fairly consistant in bringing a weak trough over the ridge and through the Pacific Northwest and Norcal late Sunday or Monday but differ on timing a bit. GFS and ECMWF even paint a little precipitation over the far north state. If any precipitation does occur it would likely be north of the CWA. Regardless…most areas should see at least a slight bit of cooling on Sunday. Even with the cooling, most areas will see highs on Sunday a little above normal for mid August. Other effect of this trough will be some breezier west winds across the Sierra crest. Most models shift weak low east of the CWA by Monday so airmass should see some warming again with highs Monday likely similar to Saturday.
Extended discussion (Tuesday through Friday)
The extended period will be dominated by a series of weak upper level troughs moving through Northern California. Longer range models are starting to form a consensus of a closed upper low forming off the California coast late next week as high pressure builds over the Great Basin. This is a pattern that is often supportive of monsoonal moisture moving northward along the Sierra from the southern deserts. Have introduced slight chance of thunderstorms along the Sierra next Thursday and Friday. Otherwise, temperatures are expected to remain above normal through the extended period.