Weather Watch

El Niño may still deliver on Central Coast in March and April

Randee Hedrick on her horse, Colonel, and Frankie Mello on his horse, Bunny, ride along the Pecho Coast evaluating the grasses growing after this winter’s rains. “It’s the most we have seen in more than four years,” Mello said.
Randee Hedrick on her horse, Colonel, and Frankie Mello on his horse, Bunny, ride along the Pecho Coast evaluating the grasses growing after this winter’s rains. “It’s the most we have seen in more than four years,” Mello said.

In January, well above normal amounts of rain fell in most Central Coast locations.

About 6.51 inches of rain fell at Cal Poly in January, or about 132 percent of normal. The previous January, Cal Poly only recorded 0.07 of an inch. From 1893 through 2015, San Luis Obispo has averaged 4.96 inches of rainfall each January. (The Tribune’s rainfall total on its weather page comes from the San Luis Obispo County Airport, where less rain falls than at Cal Poly. It showed 5.17 inches for January).

In the North County, Paso Robles Municipal Airport received 3.49 inches of rain, or about 127 percent of normal for January. Last January, Paso Robles reported 0.24 of an inch, or about 9 percent of normal. Along the Pecho Coast, the rain gauge at Diablo Canyon Power Plant recorded 4.46 inches, or about 140 percent of average. Last January, only 0.11 of an inch of rain fell at Diablo Canyon.

Farther south, the Santa Maria airport reported 2.93 inches of rain this January. Normally, the airport receives 2.75 inches. On the other side of Point Conception, Santa Barbara reported 5.79 inches, or about 165 percent of normal.

By the end of January, most of the local weather forecasters, including myself, felt confident that the wet El Niño gravy train pattern would continue.

However — in the heart of our rainfall season, no less — the weather pattern reverted to one we’ve seen over the last four years of drought, when a strong ridge of high pressure settled over the West Coast, forcing the storm track northward. Consequently, this condition created persistent Santa Lucia (offshore) winds, near or record-breaking warmth, and dry and clear skies despite this year’s record-breaking El Niño event.

The warm weather has established the grasses in many parts of the Central Coast, according to Frankie Mello, who has ranched in the area for most of his life. If the heavy rains do come, the new vegetation will help reduce soil erosion.

Heavy rains may be on the way, and here’s why.

“It’s looking likely that we will whiplash from a weather pattern that resembles July to one that looks like March,” William Patzert, a respected climatologist with Caltech’s NASA Jet Propulsion Laboratory in Pasadena, told me over the phone Friday.

Dr. Patzert suggests the current El Niño might still be too big for Southern California, and the inland areas to receive heavy rain. The 1997-98 very strong El Niño event peaked in November and by February 1998 had shrunk to a much smaller size along the Eastern Pacific. This year’s El Niño event peaked much later — in fact, just last month.

His hypothesis states that the southern branch of the jet stream will shift southward later this month and take a position over Southern California. That will allow the storm door to swing open for the later part of February, March and into April for the central and southern parts of the state. Historically, the 1997-98 El Niño, along with the 1982-83 winter, produced its heaviest rainfall in the February-through-March timeframe, as well. Both of these El Niños were late bloomers.

In other words, “The year’s very strong El Niño will be slow to start but fast to finish,” Patzert said.

While I believe the heavier rainfall will come soon, and it should put a significant dent in the drought, it won’t completely mitigate it. Water will always be a concern here in California. So far, most of the lake and reservoir levels in San Luis Obispo and Santa Barbara counties haven’t increased much.

The last major El Niño storm season in 1997-98 created widespread flooding and caused power outages impacting more than 1 million PG&E customers. PG&E has been preparing for storms like those, while urging its customers to be ready for natural disasters. That includes having a family emergency plan and keeping emergency kits for your home, your office and your vehicle. PG&E offers emergency-preparation tips on its website at www.pge.com/en/safety/preparedness/index.page.

John Lindsey’s column is special to The Tribune. He is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at pgeweather@pge.com or follow him on Twitter @PGE_John.

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