A 1,040-millibar Eastern Pacific High combined with 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 make for dry and cool weather across San Luis Obispo County. The North County will see morning minimum temperatures reach the low 20s. By the way, the record low in Paso Robles during the month of January is 12 degrees. Moderate to fresh (13 to 24 mph) northeasterly (Santa Lucia) winds should keep many of the coastal valleys just above the freezing level this morning. However, if these winds don’t develop as advertised, temperatures will fall below the freezing level.
Today’s maximum temperatures will rise to the low 50s in the North County and low 60s elsewhere under clear skies. The Santa Lucia winds will decrease tonight into Tuesday morning and allow overnight temperatures to drop below the freezing level in many coastal valley locations and areas near the beaches.
A gradual warming trend will develop Wednesday into Friday with coastal valley and beach locations reaching the low 70s. Minimum low temperatures will go up a bit on Wednesday and then slowly rise through the week. Fair weather is expected to continue through the Martin Luther King holiday weekend. The dry weather should persist into next week with the next chance for precipitation probably not happening until Jan. 25.
Today’s 3- to 5-foot (295-degree deep-water) swell (with an 8- to 13-second period) will decrease to 2 to 4 feet (with a 7- to 16-second period) Wednesday and will remain at this height and period through Friday morning.
A very intense 936-millibar storm with hurricane force winds is forecast to develop west of the international date line Tuesday then move northward toward the Aleutian Islands. If this storm develops as advertised, one of the longest period northwesterly (300-degree deep-water) swell trains that I’ve ever seen could arrive along our coastline Friday afternoon at 3 to 4 feet (with a 25- to 29-second period). This swell will gradually build 5 to 7 feet (with a 22- to 25-second period) Saturday.
This northwesterly (300-degree deep-water) swell will peak Sunday at 7 to 9 feet (with a 19- to 21-second period), decreasing next week.
Seawater temperatures will range between 52 and 54 degrees through Friday.