On Monday, we roll into the first day of winter, the shortest day of the year. During Monday’s winter solstice, San Luis Obispo will see about nine hours and 47 minutes of sunlight.
Our longest day, during the summer solstice in June, has about 14 hours and 31 minutes of sunlight. This condition is due to the 231⁄2-degree tilt of the Earth on its axis.
If you traveled north this month, the days would become shorter and shorter until you reach the Arctic Circle, with its seemingly perpetual darkness.
After reading Jack London’s short story “To Build a Fire,” which is about a man hiking by himself on the Yukon Trail on a brutally cold winter’s day, I wondered what were some of the coldest temperatures in North America.
According to the National Weather Service, the coldest temperature last winter occurred in Chicken, Alaska, where the temperature reached 72 degrees Fahrenheit below zero. Chicken is a small town on the Taylor Highway near the Yukon border with an airstrip and post office, where I spent two summers mining for gold back in the mid-1970s. Wednesdays were always a big day because of the weekly mail delivery by aircraft.
One of the more enjoyable events that occurred in Chicken was listening to the stories that the local teacher, Anne Hobbs Purdy, would share. As a skinny teenager, I couldn’t wait to hear her bear stories. Later that year, a novel she wrote called “Tisha” would become a bestseller.
The all-time record low temperature for the United States occurred at Prospect Creek Camp, Alaska, which plunged to 80 degrees Fahrenheit below zero on Jan. 23, 1971. Prospect Creek Camp is along the Alaska pipeline just north of the Arctic Circle.
The lowest temperature recorded in California occurred on Jan 20, 1937. The mercury dropped to 45 degrees below zero at a former settlement and brewery named Boca in Nevada County just west of Truckee. This ghost town lies at an elevation of 5,526 but can be seen only when the Boca reservoir is low enough to reveal the town’s old foundations.
In San Luis Obispo the lowest temperature recorded occurred Dec. 13, 1987, when the mercury hit a low of 12 degrees. On the north side of the Cuesta Grade, Paso Robles hit a low of 8 degrees back on Dec. 22, 1990.
Temperatures in few of the inland valleys of San Luis Obispo County have probably been colder. These temperatures may not be cold enough for Jack London to write a story about, but cold enough for those of us from the lower 48.
This week’s forecast
The ridge of high pressure over the Great Basin will give one more day of gentle offshore winds and relatively mild temperatures.
After this morning’s patchy dense ground fog burns off, temperatures will reach the mid- to high 60s throughout our area under hazy sunshine and variable high-level clouds. Tule fog in the San Joaquin Valley will persist through Monday morning.
A 995-millibar low and associated cold front will approach the Pacific Northwest late today and will push the high-pressure ridge over the Great Basin eastward, allowing a cold front to approach our area.
As this cold front approaches from the north, increasing clouds and cooler temperatures will develop on Monday. Light rain showers will spread southward, reaching our area Monday night.
Snow will become moderate across the central Sierra Monday afternoon with about a foot of new snow expected above 5,000 feet around Lake Tahoe and further south to Yosemite.
The main effect of this cold front for the Central Coast will be strong to gale force (25-38 mph) northwesterly winds with higher gusts and even cooler temperatures on Tuesday under mostly clear skies.
With clear skies and a somewhat dry air mass in place, morning temperatures on Wednesday will be on the cool side, with readings in the 30s to low 40s. Fair weather is expected through at least Christmas day with increasing ground fog during the night and morning hours across the interior toward the end of the week.
At this time it looks like rain will return late next week.
Surf and sea report
A 3- to 5-foot westerly (270-degree deep-water) swell (with an 11- to 17-second period) will arrive along our coastline this afternoon, increasing to 7 to 9 feet (with a 14- to 16-second period) on Monday.
Strong to gale force (25-38 mph) northwesterly winds along the California coastline will produce an 8- to 10-foot northwesterly (300-degree deep-water) sea/swell (with a 5- to 18-second period) on Tuesday, decreasing to 6 to 8 feet on Wednesday.
A 5- to 7-foot northwesterly (290-degree deep-water) swell (with an 11- to 20-second period) will arrive along our coastline on Thursday, increasing to 6 to 8 feet on Friday.
The longer-range models are still indicating a 968 millibar storm developing in the North Pacific next week. High swell conditions from this storm are expected along our coastline next Saturday and Sunday.
Energy saving tip
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John Lindsey is a media relations representative for Pacific Gas and Electric Co. He is also a local weather expert and has lived along the Central Coast for more than 22 years.