October 2010, the Mono Basin’s warmest October since 2005, set a new record for precipitation in Lee Vining: 3.74 inches! With data going back to 1988, last month beat the old record of 2.41 inches set in 1992 by 1.33 inches! It also beat the 1950-1988 October precipitation record from the Mono Inn, the previous home of our weather instruments (5 miles north). Median October precipitation in Lee Vining is 0.23 inches, usually our third driest month after June and July.

At Cain Ranch, just five miles south but slightly drier, 3.11 inches of rain set a new record going all the way back to 1931! (more…)

October 1, 2010 was the first day of the 2011 Water Year—Happy New Year! A Water Year in the Mono Basin runs from October 1 to September 30th. This lumps the winter’s precipitation into the same year as the following summer’s runoff, as well as the next year’s growing season.

The 2010 Water Year (October 1, 2009 — September 30, 2010) was near-normal (more…)

Now available on the Mono Basin Clearinghouse are documents pertaining to the construction of the Mono Basin extension of the Los Angeles Aqueduct:

Map of the LA Aqueduct facilities from Lee Vining Intake to West Portal
A 4.3 megabyte download, this high-resolution JPG file shows the control stationing and original names of most of the features of the Mono Basin portion of the LA Aqueduct. Click on the image at right to enlarge, or click on the link above to download the full map.

1933 Map of Mono Basin property ownership, hydrographic stations, wells, test holes, gages, and streams
A 2.4 megabyte download, this high-resolution PDF file shows the Mono Basin as of 1933. Included on the map are (more…)

We’ve just posted Lee Vining weather data for June 2010 on the Mono Basin Clearinghouse. It was a windy June, with an average wind speed of 4.7 mph–the highest average wind speed since 2001′s 5.1 mph (2005 came close with 4.6 mph). The maximum wind speed of 47 mph was unremarkable.

It was also warm at night in June. The lowest minimum  temperature of 37.6 F was the highest since 2003′s 40.6 F (unofficial data). The average minimum temperature (more…)

May 2010 was almost as cold as May 1998. The average temperature this May was 46.6 degrees F, making it the second-coldest May in Lee Vining since weather records started in 1988. It also set a new record low, 20 degrees, 1 degree colder than the previous May record in 2000. The average minimum temperature of 33.9 also set a new record, beating 1998′s 34.16.

Eight daily records were set last month, with seven of them broken the week of the 23rd through the 29th. Four days set new records for the lowest maximum temperature and four set new records for the lowest minimum temperature ever recorded in (more…)

The Los Angeles Department of Water and Power submits annual compliance reports in May to the State Water Resources Control Board. The May 2010 report was recently distributed and we’ve posted each section on the Mono Basin Clearinghouse. You can download the cover letter, the status of compliance report, the operations plan, the fisheries report, the tributaries report (geomorphology, hydrology, and vegetation), and the waterfowl report.

This is the first big update that we’ve had a chance to do since October 2008.  We’ve got quite a backlog of updates to get through, and in this update we’ve gone back  as far as October 2009. One major change since our last update is that the internet has so many more resources on it now. We used to be able to keep a pretty good handle on what Mono Basin resources were out there on the internet, but now every time we do a Google search we find new and valuable sources of information that we did not know about. This explosion of Mono Basin content means that (more…)