Upper jet at 250mb peaks about 115knots and SW/NE emanating out of upper cutoff. It is is producing a few showers in the front left exit region, offshore the Bay Area. The showers are moving through mainly Alpine County well north of Mammoth. The upper jet is expected to weaken later today and so showers will become more isolated by then. The upper cut off is now getting the boot and will initially build up heights over Ca Monday and Tuesday before coming through as a weak open short wave Wednesday. No precip is expected from this system in the Mammoth area. Just partly cloudy skys and about 10 to 12 degrees of cooling. Wednesday. HT 500 mb heights will rise again above 582dm….into the following weekend, and beyond into the following week. So warmer then normal temps “over all” are expected through most of the rest of October.  The idea for an early Winter (October) is most-likely not going to happen.

Next change:

About the end of October, the fantasy charts continue to bring a pretty strong wave into the west coast. However so far, what the Dweebs see is that the western pacific Long Wave high still remains parked about 1000 miles west of the dateline. So,  “that” waves energy is destined to remain too far to the north to bring Mammoth much more then clouds, winds and cooling. At this time…..With MJO in phases 1 and 2 and with periods of splitting of short wave energy about 140 to 145 west,  the west coast long wave ridge will likely favor the far west insuring more beautiful Indian Summer weather….well into early November…..

The Dweeber………………………:-)

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.