Sandwiched between the stifling heat to the east and the cold Pacific to the west resides a meteorological Goldilocks zone that we call San Luis Obispo County. Not only does the county offer some of the best weather in United States, but its rugged coastline with its prevailing northwesterly winds and its stunning bays offer some of best sailing along the California coast. One of its bays, San Luis Bay, could very well be one of the most unique sailing locations anywhere on Earth.
Let me explain. Bob Dylan once wrote, “You don’t need a weatherman to know which way the wind blows.” If one reviewed historical wind data, chances are you don’t need one. Traditionally, according to wind data recorded at the Diablo Canyon nuclear power plant’s meteorological tower, the winds blow about 60 percent of the time out of the northwest quadrant along the Pecho Coast. The winds blow about 12 percent of the time out of the northeast quadrant and out of the southeast quadrant about 23 percent of the time. The other 5 percent of the time, the winds are spread evenly across the rest of the cardinal headings.
Much of the San Luis Bay coastline is orientated toward the south-southeast and sheltered from the prevailing winds by the Irish Hills. Consequently, the northwesterly, northerly and northeasterly winds often blow offshore there roughly 75 percent of the time. As these winds descend down the Irish Hills, the air mass is warmed due to compression. That’s why it’s often the sunniest and warmest beach in the county. Of course during winter storms, the associated southeasterly winds and rains can turn the bay into a brown water washing machine. But overall, the waters are usually calm.
Mark Kocina and his wife, Jen Carroll, have been sailing the Pacific and Atlantic oceans for decades. San Luis Bay has become their favorite location for their sailing boat, Spirit.
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Mark told me, “No other location that I am aware of can take you from gentle winds and calm waters of the bay, to the strong northwesterly winds and blue waters and white frothy foam of the Pacific — in less than one nautical mile.”
He went on to say, “This creates a near perfect opportunity for the first-time sailor to experience the joys of sailing in the gentle conditions of the bay and transition to the rougher outer bay waters in just a few minutes.”
This condition allows the basics of sailing and boat handling to be taught in a safe and predictable environment. In other words, if you happen to begin to feel just a wee bit of queasiness in the high seas of the outer waters, you can simply make your heading toward the beach and be in the calm waters in literally two or three minutes. To give you an idea of how strong these gradients can be, in September of 2008 at Pops by the Sea in Avila Beach, it was hot. A fishing boat at Port San Luis reported a temperature of 105 degrees near the Harford Pier. As the boat moved past the breakwater toward the wind shift line, the temperature dropped 37 degrees in less than a quarter mile. About a half-mile farther out to sea, the temperature reached 60 degrees. That’s what you call a temperature gradient!
I presented a paper on the microclimate of San Luis Bay at a meteorological conference that I attended on the East Coast. To be honest, many weather forecasters were understandably skeptical about such severe temperature changes in such a short distance. But I think their reaction indicated what a special place that we all live in. Today’s weather report The last time San Luis Obispo experienced rain was April 23. Some of the coastal areas, such as Baywood Park and Cambria, have recorded about 0.05 inches of precipitation since July 1 because of periods of heavy drizzle during the late-night and morning hours.
Saturday’s moist and unstable monsoon air mass interacted with an upper-level low-pressure system positioned off the coast of California and produced widely scattered light rain showers along with a few thunderstorms. San Luis Obispo County Airport reported 0.01 inches of rain, while the PG&E Energy Education Center in Avila Valley recorded 0.02 inches of precipitation. Most other areas reported only trace amounts of rain.
A return to fairly typical summer weather has developed this morning with low clouds and fog along the beaches and in the coastal valleys. Today’s high temperatures will be slightly below normal, but will transition to slightly above normal by Tuesday.
The Eastern Pacific High will nudge closer to the California coastline today and produce a steeper pressure gradient. This gradient will give increasing northwesterly winds during the afternoon hours beginning today.
These winds will reach strong to gale force (25 to 38 mph) levels by Wednesday and will mix out the temperature inversion layer during the afternoon hours. This condition will produce a much greater amount of sunshine along the beaches during the late morning and afternoon hours beginning this afternoon and continuing through next week.
The large high pressure ridge over the Great Plains will begin to shift west, which will produce warm and dry conditions across the North County, with temperatures for interior locations expected to be in the high 90s and maybe the low 100s by the end of the week.
Today’s surf report
A 2- to 3-foot northwesterly (310-degree deep-water) swell (with a 7- to 9-second period) will continue at this height and period through this morning.
Increasing northwesterly winds will generate a 3- to 4-foot northwesterly (320-degree deep-water) sea and swell (with a 5- to 9-second period) this afternoon and will remain at this level through Monday.
Four- to 5-foot northwesterly (320-degree deep-water) seas (with a 5- to 7-second period) is forecast along the coastline Tuesday through Friday.
Arriving from the Southern Hemisphere
Today’s 1- to 2-foot Southern Hemisphere (200-degree deep-water) swell (with a 14- to 16-second period) will continue at this level through next Sunday.
A very long-period
(22-plus seconds) Southern Hemisphere (165-degree deep-water) swell will arrive along the California Coast on Monday, but it’s coming from a southeasterly direction and will have very little effect along the Pecho Coast. Longer-range models and charts still do not indicate a lot of storm activity in the Southern Hemisphere at this time.
Seawater temperature will range between 54 and 57 degrees through Monday. Seawater temperature will decrease to 53 and 56 degrees Tuesday, further lowering to 52- to 54 degrees on Wednesday through Thursday.
Did you know?
PG&E employees from Diablo Canyon Power Plant helped support Make-A-Wish last Friday by raising funds at the 15th annual Nuclear Challenge Golf Tournament held at Monarch Dunes in Nipomo. PG&E employees along with their family and friends took part in the tournament to benefit the foundation’s Tri-Counties chapter. Make-A-Wish grants the wishes of children with life-threatening medical conditions.
John Lindsey’s column is special to The Tribune. He is a media relations representative for PG&E and longtime local meteorologist. If you have a question, send him an email at firstname.lastname@example.org.