Fresno County’s preparations for the atmospheric river storm bearing down on Central California include issuing an evacuation warning for foothills residents stretching from the Madera County line on the north to Tulare County on the south.

The seriousness of Thursday’s storm cannot be overstated, National Weather Service meteorologist Kristian Mattarochia told reporters Tuesday afternoon during a media briefing.

The heavy snow that has accumulated at low elevations in the foothills over the past week will be hammered by 6 to 8 inches of rain falling Thursday through Saturday, Mattarochia said.

“We know there’s been a lot of storms this year, to say the least. But we need to get the word out that this storm will be unlike any other wet weather event so far this season,” he said. “It’s just really important that we communicate the severity of the situation so you can stay safe, and you can get ready. The amount of rain we’re receiving, considering what has already fallen, is unprecedented countywide. It doesn’t matter if you’re in the mountains, if you’re in the city of Fresno, if you’re in the western half of the county near Coalinga, we are expecting water problems to really affect everyone’s life.

“So again, why we are all here today, is to make sure that you stay safe and know that this is not a garden variety storm. This is something, again, that will bring impacts to daily life never experienced before.”

The atmospheric river bearing down on Central California will arrive earlier Thursday and bring twice as much rain as forecasters had predicted on Monday.

The National Weather Service in Hanford is predicting 2 to 3 inches of rain in Fresno and 6 to 8 inches of rain in Shaver Lake from Thursday through Saturday, with the heaviest rain starting at sunset Thursday and continuing overnight into Friday.

“It looks like right now the certainty for the atmospheric river to hit Central California has increased. It looks like while we’re not necessarily in what they would call the bull’s-eye, we are now closer to the bull’s-eye,” meteorologist Carlos Molina told GV Wire on Tuesday morning.

Evacuation Warning Gives Residents Time to Prepare

The expected deluge, which comes after a series of Valley rainstorms and Sierra snowstorms that have saturated soils, has put local, state, and federal officials into a heightened state of planning and preparation.

Fresno County’s Office of Emergency Services has created a webpage with links on road closures, Caltrans and CHP, and a link to how residents can sign up for alerts from the sheriff’s office for emergency notifications such as evacuation orders.

Sheriff’s Office Lt. Brandon Pursell emphasized to reporters at the briefing that Tuesday’s evacuation warning was not an order and was being issued to give residents time to prepare in case they may need to evacuate as a result of the storm.

Officials are paying close attention to the area on the Kings River above the weir near Piedra where stormwater could surge uncontrollably out of creeks, he said. The sheriff’s office also is “incredibly concerned” about the potential for flooding along the San Joaquin River.

“There is a big storm coming and it could potentially cause a lot of flooding,” Pursell said. “It could potentially cause roadway washouts. And we want you to be prepared for that. We’re not asking people to run out of their house and go seek shelter. What we’re asking you to do is to be diligent in your situational awareness.”

If evacuations do become necessary, Fresno County emergency officials will work with the Red Cross to set up shelters, emergency manager Terry Mejorado said. Cities such as Fresno already have warming centers in operation that can take residents in need of shelter.

Resources such as water rescue teams and public works are being positioned across the county to be prepared in the event of emergencies, Pursell and Mejorado said.

Emergency services teams are meeting three times a day to plan for the upcoming storm and its impacts, Mejorado said.

“We are just being as absolutely as proactive as we can, knowing that we can’t mitigate everything that we’ll experience over the next week. We want to make sure that we’re doing what we can to not only prepare ourselves to respond, but the best that we can do to prepare the community,” she said.

Dam Releases Increasing

The forecast for heavier rain and more snowmelt has prompted the U.S. Army Corps of Engineers to increase water releases from Pine Flat Reservoir, spokesman Tyler Stalker said Tuesday.

“We are increasing releases, actually, today. We’re increasing flood control releases up to about 3000 CFS, which is cubic feet of water per second,” he said. The flood control releases are on top of water releases requested by downstream customers, Stalker said.

Even though Pine Flat was about 56% of capacity on Tuesday, engineers are engaged in the delicate balancing act of releasing only as much water as is necessary while still releasing enough to make room for what will likely be a massive amount of water coming later from this winter’s snowmelt, Stalker said.

Releases this weekend could be as high as 6,000 CFS, and officials are trying to control the releases now rather than have much larger releases later that will strain downstream levees, he said.

Flooding occurred on the lower Kings River in 2017 after levees failed in June at the Kingsburg Gun Club and Kingsburg Golf and Country Club. At the time, the U.S. Army Corps of Engineers had increased releases to as much as nearly 15,000 CFS after a triple-digit heat wave rapidly melted part of the Sierra snowpack.

San Joaquin Snowpack ‘Huge’

The U.S. Bureau of Reclamation, which oversees Friant Dam, is preparing to release 2,000 to 3,000 CFS starting Friday to reduce Millerton Lake levels, said Michael Jackson, area manager of the South-Central California Area office in the California Great Basin.

That’s on top of the 3,900 CFS that’s already being released for water customers served by the Friant-Kern and Madera canals, he said.

The lake is not quite at half capacity now, but managers want to make sure there is room for water from future rainstorms and snow melts, he said. In the upper San Joaquin River watershed, “we’re about 217% of average … outpacing 1983, which is the largest year on record so far,” Jackson said.

Water managers up and down the Valley need to coordinate releases as much as possible, since many rivers, such as the Merced, flow into the San Joaquin as it journeys northward and empties into the San Francisco Bay Delta.

And the San Joaquin also takes water from the Kings River, Jackson said: “There’s a part where they can divert some over to the San Joaquin, and they are doing some of that now.”

Thursday’s Storm Arriving Earlier

The updated forecast calls for Thursday’s storm to arrive a little sooner and with more intensity, Molina said. Coalinga on the west side of the Valley, which typically is shielded by the coast range, could get as much as 1 inch of rain, he said.

The weather service is predicting a slight chance of “excessive” rainfall that will lead to flooding in localized areas, including city streets and mountain streams and creeks, Molina said.

“Once you start getting over 1 inch in a 12-hour period, that is enough rain to kind of overwhelm the sewer systems in this area,” he said.

The atmospheric river is coming into California with warm air and moisture from Hawaii that could raise the daytime high to 70 degrees by Sunday. Rain is now predicted to fall at higher elevations, with snow above 8,000 feet, Molina said.

The warmer weather and heavier rain could melt the snow up to about 3,500 feet, with snow at higher elevations becoming more slushy and icy but not completely melting.

The only river flooding danger at this point is for the Merced River, Molina said. No flooding is forecast for the San Joaquin or Kings, although water levels will rise in the days following this week’s storm as runoff flows down mountain creeks and streams.

And the atmospheric rivers might not be done with us yet — Molina said a weaker one is expected next week, arriving Tuesday or Wednesday.

Fresno County Flood Control Map