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.

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Last week, Lee Vining Creek peaked on Thursday night, June 23, at approximately 536 cubic feet per second (cfs), according to preliminary data from the Los Angeles Department of Water & Power (DWP). Southern California Edison is releasing additional water from Saddlebag Lake Reservoir and almost the  entire natural flow from Tioga Lake Reservoir, which resulted in a very high peak flow on Lee Vining Creek. This peak flow was about the same as last year’s average daily peak flow, which had only been exceeded (more…)

April in the Mono Basin was near-average, but slightly on the cool, dry, and windy side when compared to recent years. Although the high temperature on April 1st was 72 degrees F, the last two weeks struggled to get out of the 50s. It was our windiest April since 2004, with an average wind speed of 4.9 mph in Lee Vining. The 58 mph high-wind-gusts this April and last April were not out of the ordinary. You can see our April weather log here.

This year April brought wind, cool temperatures, and average precipitation to the Mono Basin. Photo by Arya Degenhardt.

Lee Vining precipitation in April was (more…)

Every April, after the April 1st snow surveys are in, the Los Angeles Department of Water & Power (DWP) issues a preliminary April 1st runoff forecast, and then a final forecast update in May. The April 1st forecast for the Mono Basin for the April 1 2011–March 31 2012 runoff year is 147% of average!

We always get asked why the runoff forecast is different than the snowpack—if the snowpack is 169% of average, shouldn’t the runoff be the same? The simple answer is that the snowpack is extremely variable, and some of it soaks into the ground or sublimates into the air—so not all the water in the snow becomes runoff.

Since the State Water Board decision in 1994, only two years have had more than 147% runoff (more…)

The April 1st snow surveys in the Mono Basin found 169% of average snowpack in the headwaters of Rush Creek and Lee Vining creeks. Snow water content ranged from 133% at Gem Lake to 187% at Ellery Lake.

A typical spring day in the Mono Basin: snowstorms edging their way over the Sierra Nevada. Photo by Arya Degenhardt.

The March storms were relentless, with only nine days during the month when the Gem Pass snow pillow did not record an increase in snow water content. In Lee Vining it was our wettest March since 1995, with over 4 inches of precipitation. It was our snowiest March on record (since 1989), barely beating March 2001′s 43 inches of snowfall by 0.8 inches.

We are still waiting for the Los Angeles Department of Water & Power to release the preliminary April runoff forecast (to be finalized in May), but based on the snowpack, it might be a similar runoff year to 1998, 2005, and 2006—somewhere in the 140–150% of average range. We’ll post an update when we have more information—but Mono Lake will definitely rise a lot this year!

Mono Basin March 1st snow surveys aren’t all in yet, but so far surveys in the Lee Vining Creek drainage have been completed. In percent of the April 1st average snow water content, Tioga Pass was 105%, Saddlebag Lake was 110%, and Ellery Lake was 128%. This averages 114% for April 1st and 134% for March 1st.  Statewide, so far the totals are 109% for April 1st and 124% for March 1st, and ranging from 66% for the Scott River to 225% for the Tule River (March 1). The basins adjacent to Mono (more…)

The Mono Basin’s wet weather suddenly ended January 3rd, and aside from 0.16 inches of precipitation on January 30th, there was no measurable precipitation until February 16th! That is 27 dry days in a row, then one day of precipitation, followed by another 16 dry days! Total January precipitation in Lee Vining added up to (more…)