Weather Watch

People do something about the weather

The spread of personal wireless weather stations that are connected to the Internet has revolutionized weather observations. These home weather stations are affordable, reliable, accurate and can be placed almost anywhere.

They are particularly suited to areas such as San Luis Obispo County, which has an abundance of microclimates. For weather enthusiasts, it is fascinating to compare their community’s rainfall totals and temperature ranges with those in other parts of the Central Coast. People with orchards, vineyards and gardens can tell if the air temperature is dropping toward freezing and take measures to protect from Jack Frost. It’s also nice to know how much rain has fallen so you don’t turn on your sprinklers unnecessarily.

One of the more interesting applications for this type of weather station can be found at the Point San Luis Lighthouse. If it rains too much, the serpentine soils that compose parts of the Pecho Coast Trail that leads to the lighthouse become slippery. Because of safety concerns, PG&E will cancel the hikes that occur on Wednesdays and Saturdays until the soil dries enough for safe walking.

PG&E is the steward of the lands that surround the lighthouse and the trail. The actual lighthouse property and buildings were transferred from the Coast Guard to the Port San Luis Harbor District in 1992. In 1995, the Point San Luis Lighthouse Keepers was formed to take on the responsibility of restoring and maintaining the lighthouse.

A few weeks ago, Ken Irwin of the Lighthouse Keepers and Chris Arndt of installed a Davis Vantage Pro 2 weather station donated by PG&E to more accurately determine rainfall amounts near the Pecho Coast Trail.

This weather station will also let docents, hikers and Point San Luis Lighthouse trolley riders know the current temperature and winds at this jewel of the Central Coast by using their smart phones and logging onto the website. Having this type of data so readily available at the touch of a button on your cell phone would have seemed like science fiction just a decade ago.

Arndt, an electronics wizard, first installed a weather station at his home in western San Luis Obispo back in 1998 and a few years later put it on the Internet. He later added a lightning detector, which became very popular with local weather buffs and meteorologists.

He gave his parents a Davis wireless weather station. They later asked Chris if weather information from their station could also be displayed on the webpage. He designed and built his own interface box that plugs into any cable/DSL network router, allowing the weather station data to be displayed on his website.

Over the years, he’s added 10 weather stations, ranging from the top of the Condor Lookout facility, at 3,190 feet on Hi Mountain about 15 miles east of San Luis Obispo, to the coast at the Point San Luis Lighthouse and areas in between. He has plans to add weather stations throughout San Luis Obispo County.

Another site that has quite a few local wireless weather stations is the Weather Underground site at www.wunderground .comWeather data from other wireless stations throughout America and the rest of the world can be viewed from Davis Instruments’ website at www.davisnet .com/weather/cool/world.asp.

For information about visiting the Point San Luis Lighthouse by trolley or hiking the Pecho Coast Trail, go to, or you can call 540-5771.

Today’s forecastA stubbornly persistent 1,033-millibar Eastern Pacific high about 700 miles west of Cape Mendocino, combined with a strong 1,040-millibar high over the Great Basin, will keep the storm track far to the north of the Central Coast.

This morning’s dense ground fog in the North County will burn off, leaving behind hazy sunshine this afternoon with highs reaching the low 60s.Along the beaches and in the coastal valleys (San Luis Obispo) temperatures will reach the mid-60s under clear and sunny skies. Overnight low temperatures will generally be in the high 20s to the low 30s in the North County, while the coastal valleys will cool to the high 30s.

For those traveling through the San Joaquin Valley, tule fog will linger into the afternoon, becoming quite dense during the night and morning.

A rather dry and quiet weather pattern is setting up across the Central Coast through Thursday with variable high-level clouds and subtle day-to- day changes.

Another dry cutoff low in a long series of cutoff lows this year should produce partly cloudy conditions on Thursday night into Friday morning, followed by strong to gale-force (25- to 38-mph) northerly winds Friday afternoon, followed by gusty northeasterly (offshore) winds Friday night into Saturday.

Current forecast guidance indicates dry weather continuing through Christmas if not through New Year’s Day.

Today’s surf reportThis morning’s 6- to 8-foot northwesterly (300-degree deep-water) swell (with a 16- to 18-second period) will remain at this height, but its period will decrease to 14 to 16 seconds on Monday and 13 to 15 seconds on Tuesday.

A 5- to 7-foot northwesterly (300-degree deep-water) sea and swell (with a 7- to 13-second period, is forecast Wednesday through Friday morning, increasing to 6 to 8 feet by Friday afternoon and night.

An 8- to 10-foot northwesterly (300-degree deep-water) swell (with a 15- to 17-second period) should arrive Saturday.

Preliminary analysisToday’s longer-range charts are indicating a very large storm developing off Russia’s Kamchatka Peninsula. If this storm develops as advertised, a long period swell will arrive along our coastline around New Year’s Day. Seawater temperaturesSeawater temperatures will range from 54 to 56 degrees through Wednesday, decreasing to 53 to 55 degrees on Thursday and remaining at this level through Saturday.

John Lindsey is a media relations representative for PG&E. He is also a local weather expert and has lived along the Central Coast for nearly 25 years. To subscribe to his daily weather forecast or ask him a question, email