The winter storms brought unusually heavy snows to the mountains and snowfall reaching rarely seen low elevations over the past week. "That results in a 177% of average to date and a 170% of the April 1 average at this location." "For our survey we recorded a snow depth of 116.5 inches and 41.5 inches for snow water content," said Guzman. "After almost a month-long dry spell during February, this last week brought a significant amount of rain and snow statewide, especially in the southern and central Sierra Nevada," said Sean de Guzman, who's the manager of the Snow Surveys and Water Supply Forecasting section of CDWR. The survey will also help water managers who allocate California's natural water resources to regions downstream. The data collected helps determine the amount of water that will melt and run off to state reservoirs during warmer months. The third snow survey of the season began Friday in the Sierra Nevada Mountains. (KABC) - The water content of the Sierra snowpack, which provides about a third of California's water, is almost twice the average thanks to the recent winter storms, according to the state Department of Water Resources. But if these forecasts persist, it does suggest that impacts in California could actually increase moving into summer and next autumn.The water content of the Sierra snowpack, which provides about a third of California's water, is almost twice the average thanks to the recent winter storms. That would be a pretty odd evolution, and we probably shouldn’t take ENSO projections for the summer and beyond too seriously yet as we’re still on the wrong side of the “ Spring Predictability Barrier”. Interestingly, there is pretty broad multi-model ensemble agreement that this event will persist into and even beyond summer–perhaps even strengthening further. The good news: right now, there are neither any big early-season heatwaves nor any big storms on the horizon which could trigger rapid snowmelt.Įl Niño still in the cards for this summer…and beyond?Įl Niño conditions have officially been declared, although the event has been a rather anemic one so far (and mid-latitude teleconnections were weak to non-existent for most of the winter). The large amount of water retained in the well above-average snowpack does portend a somewhat above average risk of snowmelt flooding in California this spring, though nothing like the extreme risk faced by nearly the entire Midwest and Mississippi River basin in the coming weeks. That suggests that the snowmelt season will likely begin to accelerate in the next 10 days. (NCEP via But there is one additional item of note: ensemble forecasts are suggesting that warmer-than-average temperatures will start to spread over much of the recently-cold American West by early April, despite ongoing precipitation. Warmer than average conditions appear likely to gradually overspread much of the Western U.S. (Of course, that somewhat masks the very cold conditions that occurred during February). And interestingly: temperatures for the full period really haven’t been that cold–shaking out pretty close to average for most of the state. Overall cumulative precipitation anomalies have not been particularly exceptional, which explains the relative lack of serious flood issues (with the notable exception of the Russian River flood event earlier this month due to a stalled but very localized atmospheric river). Not record wet, or record cold…but certainly enough to be noticeably damp in most spots for a nearly 2-month period and generate an extremely impressive Sierra Nevada snowpack.įor the Water Year to date (i.e., since October 1, 2018) nearly all of California has experienced slightly to moderately above average precipitation. But weather conditions since the new year could not have been more different: January and February were very cool and quite wet months across much of California. The 2018-2019 rainy season started exceptionally dry and relatively warm across most of California, and was punctuated by California’s deadliest and most destructive wildfire in history during the uncharacteristic month of November. Most of California has experienced slightly to moderately above average precipitation for the season to date.
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