Update: 'Record-breaking spring snow melt' forbodes widespread flooding in Tulare County
SAN FRANCISCO -- With more Spring-like temperatures forecast for Easter weekend, concerns were growing of the flood threat posed by the melt-off of the epic snow totals that have buried the Sierra since December 26th.
A 20-degree warmup was in store for the weekend with temperatures in the 70s predicted for the Bay Area.
"Maximum temperatures each afternoon Wednesday through Sunday will be around five degrees warmer than the previous day," National Weather Service forecasters in Hanford said. "By Friday afternoon, temperatures will reach seasonal values. High temperatures Sunday afternoon should be seven to nine degrees above normal for this time of year."
ALSO READ: Latest measurement shows Sierra snowpack at 237% of average; Flood concerns grow
Hanford forecasters have their eyes on Tulare County where southern Sierra runoff was breathing new life into Tulare Lake, which has been dry for decades.
During Monday's April snow survey by state water officials, the measurements carry with them an ominous foreboding. At the Phillips Station survey site, state water officials recorded 126.5 inches of snow depth and a snow water equivalent of 54 inches, which is 221 percent of average for this location on April 3.
Last year's survey in comparison was pitifully low. Water officials had just a small patch of shallow snow to measure after a disappointing winter. The snow depth on April 2 was just 2.5 inches -- part of a disastrous multiyear dry spell that triggered water cuts across the state.
"California's dramatic improvement in water supplies from one year ago has unfortunately led to devastating flood impacts across the state," said Sean de Guzman, the manager of the Snow Surveys and Water Supply Forecasting for the state. "We are currently forecasting record breaking Spring snowmelt in the Tulare Lake region."
de Guzman said the runoff in the Kern river water system could range from 265 percent of normal to 422 percent of normal.
And that's on top of the flooding that is already happening. In less than three weeks, the parched expanse of 30 square miles has been transformed by atmospheric river storms and snow melt runoff into a rising sea threatening farms across the rural and highly agricultural county.
Since January some 12,000 people in Tulare County have been under an evacuation orders as high water from recent levee breaches inundated a number of communities.
Dr. Andrew Schwartz, the lead scientist at the UC Berkeley Central Sierra Snow Lab, is among those who are concerned what the coming months holds once the 700-plus inches or nearly 60 feet of snow that has fallen since October in the mountains begins to melt off.
"Flooding is a concern with these deep snowpacks," he told KPIX. "Primarily through things like warm atmospheric rivers where we get rain falling on top of them that can cause rapid flooding and catastrophic consequences downstream...prolonged warm periods are also a concern."
This week state water officials will take their April snow survey. It's one of the most important of the season and expected to bring good news for the once drought stricken state.
"That's when the snowpack is traditionally at its deepest (the April survey) and has the most water content," Schwartz said. "That effectively tells us how much water there is stored in that snowpack to then run off later in the year and to keep our reservoirs full as we use them in the spring and summer and autumn for our purposes."
According to the state Department of Water Resources, the snowpack is currently around 239 percent of normal.
"Realistically, we've still in the 23 driest years in 1200 years," he said. "So, this is terrific. We want winters like this. It's reason to celebrate."
