Some nice rains fell throughout Mono County yesterday.  21 hundreds in the bucket for a weekend total of .45.  Not bad for September.

Today may be the day for heavy rain!!!! Flash flood Watch for Mono County this PM.

A day of heavy rainfall for areas from about Mammoth Lakes to the Alpine County line and on both sides of the crest especially west of the Sierra Crest, west of Bridgeport. 

All the right ingredients:

1. Clear skies this morning.

2. Deeper moisture than yesterday from the surface to 550MB

3. PWATS up to an inch

4. Strong *BRN numbers on the west side of the crest (up to 50)…West of Bridgeport, displaying strong buoyancy relative to wind shear.

    a. May not be applicable over the Sierra

5. Very light winds for slow moving storms that will track about east to west.

6. Again…..Light Vertical shear and strong buoyancy look prime in this area over the elevated heat source of the sierra.

* Bulk Richardson Number
The BRN is meant to estimate the balance between vertical shear and buoyancy, with low BRN values suggestive of vertical shear that is too strong relative to the buoyancy, and large BRN values are suggestive of multicell clusters. Intermediate BRN values favor sustained supercells. BRN values in the range of 10-45 (dimesionless) have been associated with supercells via numerical simulations.

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.