After an average fall, precipitation-wise, we recorded double the average December precipitation in Lee Vining. Between October 1st and the end of December, we have measured more snow (34.5″) and precipitation (6.5″) than during all of last winter! This represents about 50% of the average annual total.

Snow blankets the Mono Lake Committee's storefront on December 26, 2012. Photo by Bartshe Miller.

For years with similar wet Decembers (1992, 1996, 2002, 2005, 2010), the following runoff year had close-to-average or (more…)

The October 1, 2011 to September 30, 2012 water year recently came to a close. Happy new 2013 water year!

What is a water year?
It is said that hydrologists get to celebrate a new year at least four times a year—January 1st for a calendar year, April 1st for a runoff year, July 1st for a coastal California rainfall year (as well as a fiscal year), and October 1st for a water year. Needless to say, this creates challenges in organizing hydrology data.

Here in the Mono Basin, we typically use the runoff year to summarize most measurements involving stream flows, since (more…)

This summer is turning out to be drier than expected. Preliminary data for April–July show Lee Vining Creek runoff is about 1,000 acre-feet short of the 17,900 acre-feet (53% of average) forecast, Rush Creek runoff about 2,000 acre-feet short of the 23,400 acre-feet (49%) forecast, and Parker Creek runoff about 600 acre-feet short of the 3,400 acre-foot (62%) forecast. Only Walker Creek appears to be on target with its 1,300 acre-foot (42%) prediction—notably the lowest forecast of the four creeks. (more…)

As of April 1, the winter precipitation in Lee Vining added up to 45% of average, and Mono Basin snowpack measured 47% of average. The forecast for April–July runoff is 50% of average.

An average March for precipitation in the Mono Basin brought to an end the 2011 Runoff Year (April 1, 2011–March 31, 2012). The preliminary runoff total for last year is 142% of average. (more…)

The March 1st snow surveys in the Mono Basin found 33% of average snow water content to date. This is only 28% of the April 1st average, when the snowpack usually peaks. There is still much less snow in the Rush Creek drainage:

Rush Creek March 1 2012 snow course water content
Gem Pass 7.9″ (6.7 in 1977, 2.0 in 1991)
Gem Lake 7.4″ (4.8 in 1977, 3.4 in 1991)

Lee Vining Creek March 1 2012 snow course water content
Tioga 8.6″ (7.5 in 1931, 8.2 in 1976, 7.6 in 1977, 0 in 1991)
Saddlebag 9.0″ (7.1 in 1977, 3.2 in 1991)
Ellery 8.8″ (8.2 in 1976, 7.0 in 1977, 2.6 in 1991)

Based on these snow surveys, April–July runoff for the Mono Basin has been forecasted at 39% of average. This is an average (more…)

In January Mono Lake rose 1/4 foot, and it has continued rising at a slower rate in February to today’s level of 6383.9 feet above sea level. This brings it to within 0.06 feet of the mid-August 2011 highpoint (the highest level since 2007). It should keep rising for another month before it begins dropping in April due to the dry year. Dave Marquart with the Mono Lake Tufa State Natural Reserve says he will probably have to reroute a section of the South (more…)

Following a wet October and a dry November, there were only 3 days in December with a trace of precipitation in Lee Vining. Going into January, the season was at only 33% of average when measured at the NOAA rain gauge at the Mono Lake Committee Information Center & Bookstore. 1989, 1990, 1993, 1997, 1998, 1999, and 2000 were all years with similar or drier autumns, adding up to almost 1/3 of the 24 years on record at our weather station. But it was the first half of January that threw this season into the remarkable category.

On January 17, 2012, Tioga Pass finally closed for the winter as storm clouds gathered on the horizon. The only other time in history—going back to 1933—when it closed in January was when it closed on New Year’s Day 2000.

On January 21st, 2012 (more…)

The Mono Basin and Eastern Sierra were hit by intense thunderstorms last weekend, especially on Saturday. Rainfall rates of up to seven inches per hour were recorded in the Sierra! Debris flows closed both Highway 395 and Highway 120 West for short periods of time—in Walker Canyon, Highway 395 was buried under five feet of mud in places. Rush Creek above Grant Lake Reservoir reached the highest flow so far this season, around 400 cubic feet per second (preliminary data) as rainfall combined with snowmelt from the still-extensive unmelted snowfields in the upper watershed to spill through the full reservoirs.

Lee Vining WebCam view of Saturday's thunderstorm that closed Highways 395 and 120 for short periods of time.

At the Mono Lake Committee Information Center & Bookstore in Lee Vining, we recorded (more…)

As of late last week, Mono Lake’s elevation was 6383.48 feet above sea level. It has risen 1.2 feet since April 1st, and 2 feet since its winter low point in December. It rose 0.3 feet just in the last week!

Mono Lake has risen 8.6 feet since the September 1994 State Water Resources Control Board decision ordering the lake to rise to 6392 feet above sea level.

The 0.7-foot rise in June was the largest rise during a single calendar month since June 2006 and before that July 1995, and then three times in 1983: February, June, and December.

Mono Lake is now the highest it has been since September 2007. That year it dropped two feet during the second-driest year on record.

Mono Lake Tufa State Natural Reserve staff and volunteers are moving signs and boardwalk sections out of the way as the shoreline moves uphill. It is about a foot-and-a-half away from 6385.1, the high point it reached in 2006 and 1999 and the highest levels since 1972.

Lee Vining Creek continued to flow Thursday at exceptional levels following a July 5th peak at 535 cubic feet per second (cfs), resulting in a ten-foot section of the Lee Vining Creek Trail being washed out. It is on a steep hillside with a big drop from the trail to the creek. There is a short but steep detour above the washed out section.

(more…)