Monthly Archives: November 2017

Truckee River Winter Forecast: Temps up; coin-toss for wetter or drier

NOAA precipitation forecast probabilities for Dec 17-Feb 18

NOAA precipitation forecast probabilities for Dec 17-Feb 18 (click for full size)

The next 3 months, the typical winter here in western Nevada and the Truckee River basin, will determine whether we’ll see a wetter than normal water year – or drier. The forecast? Precipitation this winter currently is a toss-of-the-coin or equal chances for a wet or dry year. Just a little to our south the chances for a dry year increase; to our north the chances for a wet year increase. This forecast looks into our 90 day future from the middle of November 2017.

Whether precipitation prognostications are accurate, we’ll know on February 28, 2018! Western Nevada did get a significant rain last week with some locations in Reno reporting more than an inch of rain. (At our house we had 1.25″!) The Carson Range and the Sierra Nevada received considerably more – especially on the west side of Lake Tahoe. The Lake rose more than 3.5 inches to 6,228.1 ft. Currently, an “atmospheric river” is hitting the Oregon and Washington coast, but missing the Sierra completely. Hopefully, we’ll see storms similar to our recent dump of rain and snow coming soon. The health of the Truckee River, Tahoe, and Pyramid depend on it.

Pyramid Lake at Popcorn Rock Beach, August 2017.

Pyramid Lake at Popcorn Rock Beach, August 2017.

Over the 2-day rain event that started in the late evening of November 15, flows jumped 5-fold in the Truckee River through Reno. Truckee River flows peaked at 3,000 CFS (cubic-feet-per-second) at Pyramid Lake by November 17. As I write, flows of the Truckee through Reno are still more than 1,000 CFS and releases from Lake Tahoe dam into the Truckee River have been increased by the Federal Water Master to more than 1,000 CFS. Flows this winter in the Truckee River will be determined by the amount of precipitation we receive since currently Lake Tahoe and other reservoirs on the Truckee River are nearly full. Lake Tahoe stands today at 85% full, (last year it was essentially empty!) and the next largest reservoir in the Truckee River watershed, Stampede, stands at 90% full. A wetter than average winter means the Truckee River will see benefits for trees, plants, fish and wildlife along its entire length and Pyramid Lake will continue to rise making up for serious declines in water surface elevation suffered during the first 16 years of the century.

NOAA temperature forecast probabilities for Dec 17-Feb 18 (click for full size)

The NOAA 3 month forecast for temperature puts most of California (including all of the Sierra) and nearly all of Nevada likely to be warmer than average. It is no surprise since we’ve seen the consistently warmest temperatures in western Nevada and the Sierra during the past 2 decades. Without serious action on the climate change front, that is very unlikely to reverse itself anytime soon.

 

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Winter storm forecast for late Friday into weekend

A warm October ended with balmy days and a calm evening for the trick-or-treaters on our street. The summer-like weather that dominated October here in Reno and western Nevada may be coming to an end this Friday.

Forecast for the 5 day period beginning Nov 1, 2017. Click for full size.

Forecast for the 5 day period beginning Nov 1, 2017. Click for full size.

The National Weather Service is forecasting a storm moving into the region late Friday continuing into the weekend. The forecast calls for 50 mph winds and precipitation in the valleys east of the mountains, but for only small amounts of rain with a possibility for snow toward the end of the storm. The Sierra and Carson Range, however, may do better with moderate rain and snow called for late Friday, Saturday and Sunday.

Mid-October saw a cold front that brought around a quarter inch of precipitation at my house in northwest Reno. Most of the snow that fell in the mountains has melted. Travelers across the middle of Nevada report there is no visible snow on the mountains.

The National Weather Service Climate Prediction Center says that this is a “la niña” year and the long range forecast – November through January – calls for California and Nevada to have an “equal chance” for a wetter or dryer than average early winter season. We can always hope that it is the former not the latter.

Not surprisingly, the NWSCPC is calling for a warmer than average early winter in California and Nevada – in fact, most of the US outside of Alaska and Hawaii. Click on the maps below to see them full sized or visit the link above and check out all the forecasts.

 

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