>ATTENTION CALIFORNIA AND WEST! Shed those raincoats and jackets, It’s finally warming up

Written by on March 14, 2010 in Rest of Europe with 3 Comments

> Beautiful sunny day in Southern California

PHOTO COURTESY OF SKYSCRAPERCITY.COM

Enjoying a rooftop view of the sunset in Venice Beach, a typical spring, summer, fall scene in Southern California where warmth can last 10 months of the year!

PHOTO COURTESY OF SKYSCRAPERCITY.COM

SUMMER PREPS UNDERWAY THIS WEEK AS 80s RETURN TO SOUTHERN CALIFORNIA AFTER A WET, TURBULANT RIDE… YOU’LL BE ABLE TO DUST DOWN THOSE BBQ’s

Those of you living from San Diego to Phoenix to Las Vegas, it’s finally, finally warming up as the jet lifts north and high pressure builds, and you sun worshipers can finally head to your favorite beaches along the beautiful southern California coast..

Yes, it’s been a wet and stormy winter season for you folks. El Nino was always going to bring a stormier winter, at least it wasn’t 2005 though! and indeed there has been no real winter heat this year compared to normal and the El Nino pattern shut down the production of Santa Anas which often brings those out to the beach for sometimes several days as the LA basin all the way to the beaches can warm nicely into the 80s as strong winds out of the east, northeast blow down the mountains and funnel through the passes and canyons bringing mid-summerlike conditions in the heart of winter which is of course the wet season here.

I have had the pleasure of visiting California three times, twice to the LA area where I stayed in Yorba Linda, Orange Co and on the other occasion, my wife and I visited San Francisco for our honeymoon back in 2005. I must say I love both Northern and Southern California, a beautiful part of the world and even more beautiful is the climate to go with it.

You lucky folks that live in Southern California, you couldn’t ask for more, interior Desert (not that far from the ocean) Pine tree-lined mountains, picturesque hills, canyons and valleys and of course the famed beaches which look out onto the Pacific Ocean.

Even in the heart of winter (most winters at least) when the rest of the American population is enduring snow, ice and cold, you can enjoy some rainy, cloudy and cool days, less often is it really cold and more often you’ll see periods, perhaps several days where it gets warm, even hot when high pressure builds over the deserts and low pressure forming offshore results in a strong offshore flow of wind which blows out of the desert and over the mountains east of LA towards the coast, as these winds descend the mountains of the San Bernardino, San Gabriels and Santa Anas they warm through compression and result in heating up the air as it travels towards the coast, presenting the region with summer heat in winter.

There are so many aspects of winter in S. Cal as winters can be rainy and cool like this years (often an El Nino portrays a wetter, cooler winter) but also it can be dry, warm and often windy. Depending on what you like, Southern California is the place to be. Ski in the morning, sunbathe in the afternoon on your favorite beach, have a BBQ and a swim in the evening, yes even in wintertime, that’s of course why this region is one of the fastest growing in the nation…

MAY GRAY AND JUNE GLOOM IN A TYPICAL SEASON HIDES A RISING SUN!

We approach the time for May Gray and June Gloom which is indeed late spring into early summer, a time often complained about by many sunseeking Southern Californians as May Gray and June Gloom spoil the show from the basin to the beach.

What is this and why does this occur?
Whilst two high pressure systems rule spring and summer across southern California and wintertime is often shared by both low pressures and high pressure, with this winter of course experiencing an El Nino and as expected low pressure dominated this season. But as the sun grows stronger, so too do the high pressure cells which follow the sun northward. The Pacific High sits over the North Pacific, the Four Corners High sits over the Desert Southwest. The cold Pacific water and the cold California current run down off the California coast. As the Four Corners high intensifies with the sun, this warms the land and as the land heats, pressures at the surface drop. So, as High Pressure spins off the coast, the lowering pressures over Southern California pull winds from the Higher pressure over the Pacific towards the lower pressure over Southern California. The stronger the warming and reactive lowering of pressure means stronger winds will blow between high and low pressure. These winds blowing parallel to the California coast upwell colder water from deep below to the surface of the Pacific just off the coast, this colder water forces fog to form and from fog comes low stratus clouds.
This process means, throughout the overnight and early morning, clouds and fog roll onto the California coast as the land is cool and closer to the temperature of the Pacific Ocean surface, fog can often push well into where there is gaps in valleys or mountains are low enough for the shallow fog and cloud layer to push through and over…
By daybreak and when the sun rises above the horizon, it begins to warm the land, therefore burning off the fog which pushed in overnight. The warmer, inland areas see “burnoff” earliest, but where it’s slower to warm or where the fog and cloud is thicker, burnoff is slower and can take up till early afternoon to see clearing.
For coastal areas that have see fog bound shores throughout the morning and much of the afternoon may not see clearing as the sun has perhaps taken most of the day to burn off fog which travelled 30-50 miles inland overnight.
So, why are the May and June months most noteworthy for this fog?
The high pressure over the Four Corners are still fairly weak. Whilst heights are high enough over Arizona and the southeast Californias deserts, pressures are still low enough and therefore the sun’s heat isn’t strong enough to burn off the thick fogs but usually by the end of June when the heat is stronger, burnoff usually is quicker and often floggy skies are clear by mid-morning or even as soon as the sun’s up for the day. This will be when the Pacific high produces strong onshore winds to the coast, meaning a nice cooling relief from the blast furnace heat over the deserts and hot conditions over the sheltered coastal valleys and canyons. As the basin and valleys heat and burnoff is early, fogs peel back to the beaches where fogs may linger but winds from the Pacific high begin to intensify, keeping temps within the 70s whilst 80s and 90s may be roasting areas just 10-15 miles away…
Only when the Four corners high builds towards the Pacific, will the influence of the Pacific High’s cooling effects of both fog and wind shut down and no relief will be had, except weaker onshore breezes…
TYPICAL SUMMERTIME WEATHER DRIVEN BY TWIN HIGHS AND EFFECTS YOUR TEMPERATURE DEPENDING ON WHERE YOU ARE
HOT TO VERY HOT EAST OF THE MOUNTAINS AND INTO THE DESERT

WARM TO VERY WARM FROM THE COASTAL VALLEYS AND CANYONS TO THE BASIN

PLEASANTLY WARM TO COOL ALONG THE BEACHES.
Warm days bring, nice cool and tolerable nights.

Despite often hot days across this part of the world, the drier air allows suffient cooling by night with a reversal of windflow from onshore to offshore which makes nights more pleasant to be outdoors for an evening swim, BBQ or party. Often after sundown, fogs begin their evening commute inland, snaking their way across the basin and through openings in the hills and canyons and when deep enough, they cross up and over some lower elevated hills. Only when the high pressure cell from the Desert Southwest migrates or expaands towards the coast does daytime heat increase and nights remain warmer than normal, often remaining in the 80s to near midnight across the LA basin during times when the core or center of strongest atmospheric pressures sit over Los Angeles and the beaches rather than over Arizona and Nevada which often happens in the heart of summer and can build daytime temperatures above 100, even at the immediate coast where the influence of the Pacific high pressure cell is cut off by the stronger, more dominant Four Corners high which brings warm winds offshore.
This coming week will see upper 70s along the beaches, low to mid-80s across the LA basin and upper 80s to low 90s from the Inland Empire to low deserts, could Death Valley top 100? perhaps but high desert areas may see cooler weather still since it’s only March but warming conditions are in the offing this week as the jet stream finally pushes north and warmer air can build.
Thanks for reading.
-Mark

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3 Reader Comments

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  1. Mark'sWxWorld says:

    >Thanks John!

  2. Anonymous says:

    >Excellent, layman understandable explanation of June Gloom in Southern California. Thank you!….John

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