A 1,039-millibar high over the Great Basin will continue to produce an Omega Block along the West Coast of the United States. This condition will give a benign weather pattern with chilly mornings and warm afternoons through Wednesday.
Moderate-to-fresh (13 to 24 mph) northeasterly (Santa Lucia) winds are forecast along the north Morro Bay, Cayucos and Cambria coastlines this morning.
North County stations are reporting their 12th consecutive morning with temperatures below freezing. Today’s maximum temperatures will reach low to upper 70s throughout San Luis Obispo County and overnight temperatures similar to Sunday night.
The dominant ridge of high pressure will begin to weaken later this week, signaling the end of the Santa Lucia winds. The weakening ridge will also allow for increased moisture content in the air, which will help keep overnight temperatures a couple of degrees warmer and provide conditions favorable for fog formation. Daytime temperatures are expected to drop by a few degrees.
A weak low-pressure system is forecast to pass over the northern half of the state late Saturday. However, there is some disagreement between the forecast models regarding the formation of widespread precipitation. There is potential for the system to tap into some tropical moisture, which would increase the chance for precipitation for Sunday and next Monday.
A very long-period northwesterly (290-degree deep-water) swell peaked at 9.1 feet with a 22-second period Saturday. This swell had some of the highest energy levels in the 22-second section of the ocean wave energy spectrum ever recorded at the Diablo Canyon Waverider buoy.
Today’s 5- to 7-foot northwesterly (295-degree deep-water) swell (with a 17- to 19-second period) will drop to 4 to 6 feet (with a 15- to 17-second period) Tuesday.
A 4- to 6-foot northwesterly (290-degree deep-water) swell (with a 20- to 22-second period) will arrive along our coastline Wednesday morning, increasing to 7 to 9 feet (with an 18- to 20-second period) Wednesday afternoon. This northwesterly swell will remain at this height but with a gradually shorter period Thursday.
A 5- to 7-foot northwesterly (305-degree deep-water) swell (with an 18- to 20-second period) will arrive along our coastline Friday. This northwesterly swell will remain at this height but with a gradually shorter period through Saturday.
Seawater temperatures will range between 52 and 54 degrees through Saturday.
Weekly Forecast is written by John Lindsey, a PG&E meteorologist whose Weather Watch column appears in The Tribune on Sundays.