Published Tuesday, December 19, 2000, in the San Jose Mercury News

Weather-wise, we're living in Camelot

Special to the Mercury News  

One of the questions most frequently asked of the Weather Corner is something along these lines: ``I'm moving (or retiring) and want to find the best weather. Where can I go?''

Your climate preference is a unique balance of your comfort level and how it affects your activities. For example, some people like the cool, foggy weather along the coast, but others would rather have the hot summer days of Sacramento.

Long ago in graduate school, I developed a quantitative climate index for a hypothetical ideal climate. I based it on the perfect climate professed by King Arthur in the musical ``Camelot,'' where there was a royal decree that it would not be too hot and ``there's a legal limit to the snow.'' Of course, I call it the Camelot Climate Index (CCI).

The CCI is based on a combination of maximum and minimum temperatures, the number of days over 90 degrees and the number of days less than 32 degrees, humidity, amount of rain, days of rain, and the amounts of snow and sunshine. An ideal climate would have a CCI value of 100. Points are deducted for such things as too many days of rain, too much snow or humidity, and so forth.

So where is the ideal climate in the United States? Right here in California, of course. Of the 250 cities evaluated, San Jose's CCI of 86 gives it the second-best climate in the nation, tied with San Francisco and right behind San Diego with an 88 CCI.

Honors for the worst climate outside of Alaska go to Marquette, Mich., which scored only 54. Interestingly, Honolulu ranks seventh with a CCI of
78, while Hilo, Hawaii, with a CCI of 56, ranks 156th. That's because Hilo gets rain an average of 278 days of the year, adding up to 128 inches of

The complete Camelot Climate Index can be found at

Q.   I'm a serious amateur photographer, but have found my ability to predict sky conditions that produce a spectacular sunrise or sunset to be woefully lacking. What creates those spectacular displays, and why? Jim Kirkpatrick - Walnut Creek

A.  As a meteorologist and a not-very-serious amateur photographer, I have found that either a partial deck of middle-level clouds or a hazy day can result in pretty good sunset pictures. However, I asked professional photographer Brad Perks for some advice. Many of Perks' spectacular
images can be found on his Lightscapes Photo Gallery ( Web site. Here are Brad's tips:

Clouds create the most colorful skies at sunset. High clouds can stripe the sky in pink and purple. Billowy cumulus clouds of intense color can transform the sky into a work of art. 

Fog helps create unique images, and the Pacific Ocean provides plenty of it. A flat, compressed layer of fog rolling in at sunset is the best. A classic postcard shot is an ocean of fog swallowing the Golden Gate Bridge.

Sparkling clear nights are few and far between, but they are essential if you want your night pictures to have sharp detail. When conditions are this clear, Perks heads for the Berkeley Hills to capture shots of San Francisco. Some of the clearest nights occur as the trailing edge of a cold front sweeps through after a winter rain. High winds also can scrub the air clean.

Use a split neutral-density filter to compensate for the differences in light intensity between the bright, colorful sunset sky and the dark foreground. Part of this filter blocks out more light than the remaining section, equalizing the exposure of light and dark areas on the film and permitting more detail to show through in the darker areas.

Q. What is happening to the geese this fall? I thought they all migrated north to south yet I see them going east and west. Has the weather this year confused them? Joe Pycior - San Jose

A. I haven't been able to find an ornithologist to give me definitive information about past and present migratory patterns, but from a meteorological point of view I would surmise just the opposite. The upper-level winds, which have brought us a cooler than normal November and December, have actually been flowing more north to south than usual. But contributing to this are the mountains surrounding the Bay. While people think of the Bay as running north to south, it really is oriented northwest to southeast.

Q.  Why are deserts hot? I understand mountain rain shadows and such make them dry. Does dry lead to hot? Tom Moran - Saratoga

A.   Deserts are by definition dry, but not necessarily hot. They are simply regions where the amount of annual evaporation exceeds the amount of annual precipitation. 

Deserts cover about 30 percent of the Earth's land surface and are divided into two distinct types: subtropical and midlatitude.

Subtropical deserts cover large expanses between 10 degrees and 30 degrees latitude where global atmospheric high pressure causes the air to sink and grow warmer. These are the deserts of Arizona, the Sahara of North Africa, the Arabian Peninsula and most of Australia's interior. 

The midlatitude deserts, such as large portions of the western United States and the interior of Asia, are usually found to the downwind side of major geographic barriers such as the Sierra Nevada, Himalayas and Andes. These barriers block a large percentage of the moisture, so the downstream deserts are, as you suggest, in the ``rain shadow.''

Jan Null, a certified consulting meteorologist and owner of Golden Gate Weather Services, is a retired lead forecaster with the National Weather Service. Send him questions c/o Weather Corner, San Jose Mercury News, 750 Ridder Park Drive, San Jose, Calif. 95190. You also can telephone and fax them at (510) 657-2246 or e-mail them to

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