Quick update:

New 12z Thursday guidance for both WRF and GFS shows the upper center moving inland Monday Am in a little differently location. The 12z WRF brings the center inland over the Bay Area while the GFS is consistent in taking the center inland through Monterrey Bay. The GFS would be consistently wetter for us, as that aprox 50 mile difference, would keep more of heavier precip to the south longer.  In that the GFS is a better model 4 days out will stick with the current forecast for a light to moderate producing precip maker with some 4 to 8 inches of snow above 9000 feet between Friday night and Monday night. Worth watching is the strong upper high over Mexico and Texas that will try to take the punch out of this system as it ejects inland via California early next week. Weekend temps in Mammoth will be in the low to mid 50s…lows in the 30s before the off-shore system kicks inland Monday with cooler temps to accompany.

Longer Range: (Some current guess work)

An upper level weakness in the mean is forecasted by mid week next week.  So showers are still possible in the upper elevations…although temps will rise with snow levels.

Looking at the Deterministic 12z GFS this morning….Although the eastern pacific high shifts to 140west and high latt blocking appears to weaken off the BC coast by the 10th of June, there is still a lot of blocking over BC…and the northwest Territories, then NW over AK. The westerlies will be suppressed south under this block and then have to split with some energy trickeling to the SSE down the west coast.  So we “may” transit out of our current strong closed low pattern, to one of a late spring thunderstorm pattern. (The Dweebs have been waiting for this) This would be form of winters last winter gasp!

As little vort centers travel SSE, then eject NE through Ca through the weakness, they will destabilize the atmosphere, especially during the PM hours. As we are approach the solstice in about 3 weeks….the Solar Angle will be peaking. This will easily provide the lift necessary as we combine warming temps and periods of cooling aloft for a convective showery pattern for the high country. This happened last June and we ended up with funnel clouds near hot creek in the afternoon. The big question at this time is how much energy will be in the split?  

That will determine how dynamic the impulses will be.

Dr Howard and the Dweebs………………………..:-)

Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.