Our Summer weather thus far has been warm and dry with stronger afternoon Zephyr.  This is about to change as a weak upper low has developed west of the Bay Area this evening. This feature will move further south with time putting the high country of Mono County under at least weak upper divergence. Our air mass continues very dry and so expect mainly dry high based thunderstorms with strong outflow winds next to the rain shafts. The National weather service has issued a fire weather watch Wednesday afternoon and Thursday afternoon, as lightning over a very dry forest will likely create hazardous conditions with strong gusty outflow winds. Most Storms will be over Northern Mono County Wednesday but develop further south over Southern Mono County Thursday.

 

High temperatures moved into the low 80s Today. The bump up from the upper 70s was probably due to a weakened zephyr. Little change in temps are expected with highs in the low 80s. The upper divergence that is currently developing will weaken this weekend. Thus thunderstorms will become more isolated. Note this is not the Summertime Monsoon!! (Seasonal wind)

 

Outlook for next week:

Its been long in coming but the Summertime Monsoon looks to arrive during the second half of next week. Latest guidance shows the subtropical high developing over Texas this weekend then expanding westward next week. The GFS model shows PWAT (low and mid level moisture) really increasing over Southern CA by middle of next week with hot humid weather becoming more likely during the 2nd half over So Cal.. A northerly surge is expected over most of the State by the following weekend. Although it is too soon to tell what type of focusing will highlight the pattern; it looks like we will get into a wet thunderstorms pattern during the last week of July. This pattern change next week completes the transition to our Sierra Summertime Thunderstorm pattern.