Lack of rain makes 2013 the driest on record, at least so far this year

It's official, the January-to-October 2013 period is now the driest on record at Cal Poly (home of climatology for San Luis Obispo) since 1870 when weather observations started.

The next driest was 1984, when 4.3 inches of precipitation was recorded. So far this year, only a meager 4.0 inches of rain has fallen.

By this time of the year we should have seen 16.3 inches of the wet stuff. Currently, Cal Poly is just 24 percent of normal. In the North County, it’s even worse. Only 1.5 inches of precipitation or just 15 percent of normal has been recorded. Dry indeed!

Jan Null, a certified consulting meteorologist with Golden Gate Weather Service and a former PG&E meteorologist, put together some interesting factoids in regards to San Francisco’s October rainfall data that dates back to 1849.

Ironically, both the wettest years in 1861-62 and driest in 1850-51 in the California rain season, which runs from July 1 through June 30, have occurred in years when there was no rain in October.

Going forward, the weather in November can be tough to predict. It can be cold and stormy, but big swells often make it a surfer’s favorite time of the year. A pattern of Santa Lucia winds normally develops for a few days that are often preceded by brief and strong northwesterly (onshore) wind events along the California coastline north of Point Conception.

These offshore winds often produce dry and clear skies with cool mornings and warm afternoons.

At this time, the long-range charts and models are indicating dry weather continuing through the early part of November. On average, 2.1 inches of rain falls during November in San Luis Obispo and 1 inch at Paso Robles.

These averages increase to 4 inches in San Luis Obispo and 2 inches in Paso Robles during December.