'June Gloom' Contributes To Cool Weather in S. Calif.
UPDATED 2 AM PDT, June 18, 2009
By WeatherBug's Stephen Baxter
This year has featured unusually lengthy periods of cloudy weather and cool temperatures caused by a phenomenon familiar to coastal southern California. The June Gloom continued Wednesday and more gloomy days can be expected before summer kicks into high gear.
Southern California beach-goers are well-acquainted with the low overcast that obscures the sun in late spring. The periods of frequently occurring low clouds within several miles of the coast are referred to as "May Gray" and "June Gloom," thanks to their occurrence in the transitional period between spring and summer.
This period of dreary weather should not be confused with the southern California rainy season, which spans the winter months. The June Gloom is not usually associated with much in the way of precipitation because it`s caused by something very different. Warmer air sweeping in from the interior is met by the still-very-chilly water off the coast. This clash often creates thick, low clouds and fog.
Residents in San Diego and Los Angeles can typically expect May and June to provide the least amount of sunshine annually, and this year has been no exception. Through the first 15 days of June, six have been cloudy in downtown L.A. while seven have been cloudy in San Diego. In the first half of the month there have been no clear days in San Diego and only two in Los Angeles. Despite the cloudiness, San Diego has recorded only a trace of precipitation and L.A. reported 0.15 inches of rain, almost all of which occurred on June 5.
The gloomy weather this season has been enhanced by the large-scale weather pattern as well. So far this month there has been a tendency for upper-level weather systems to hang around the West Coast. This aids the cloud formation over southern California.
The greater-than-normal cloudiness has helped keep temperatures below normal from L.A. down to San Diego. While the average high in San Diego is in the mid 70s, the high temperature hit 72 on Monday for the first time since May 20.
Some reprieve from the clouds is expected as the week wears on. Thursday is expected to be the first day since May 21 that L.A. reaches a maximum temperature at or above normal. However, the first half of the weekend will bring more cloudy weather back into forecast.
So when will the dreary weather break? Warmer and sunnier weather is likely next week as the weather pattern shifts to steer systems away from southern California and winds shift offshore. Also, the slowly warming ocean waters will prevent cloud formation and allow for more sunshine heading into July and August, when southern California typically sees its warmest, driest weather.
As always, keep your WeatherBug active to receive the latest weather news and information as WeatherBug meteorologists keep a close eye on weather impacting your neighborhood.
Sources: Scripps Institute of Oceanography, University of California, San Diego and the National Weather Service
What do you think of this story?
for comments or suggestions.