FORECAST - Wednesday, December, 10 2008

Sunny and mild afternoons follow clear and cold nights the next two days.

• This morning you will find widespread frost in the inland areas of the East and North Bay.
• The cloud-free sky gives our December sunshine all day to warm us a few degrees higher than yesterday.  Temperatures are cooles inland today where the East Bay struggles to reach the middle and upper 50s.  Look for upper 50s to lower 60s around the Bay with lower to middle 60s at the Coast.
• Sunny and slightly warmer by a few degrees tomorrow.
• Big changes bring cold, wet, and breezy weather to the Bay by Sunday with snow levels as low as 2000 feet. 

Earth's Average Annual Precipitation

Q: Does it typically rain about the same total, worldwide, year-in and year-out?

A: That's a big question. Firstly, the average annual precipitation of the entire Earth's surface is estimated at 41.4 inches per year. As with our climate, when and where it falls migrates.

Our atmosphere contains only 0.001% of Earth’s water but is an essential part of the global hydrologic cycle. Global water balance is achieved when evaporation equals precipitation and runoff. Studies show global warming enhances the evaporation rate and, in turn, increasing other components of the hydrologic cycle.

Computer models suggest a 7.2°F warming is expected to increase global precipitation by about 10 percent. Models suggest the increase is more likely produced by heavier rainfall instead of more frequent rainfalls or rain events of longer duration.

FORECAST - Tuesday, December 9, 2008

Clear and nearly 10 degrees cooler this morning in most neighborhoods.  Watch out for freezing fog in the North Bay until 8am.

Sunny this afternoon and warmer with highs nearing seasonal norms.  Look for middle to upper 50s in the East and North Bay, highs near 60 around the Bay, and the warmest weather along the Coast, middle 60s.

Clear and chilly again tonight with lows in the middle to upper 30s in the East and North Bay and lower 40s around the Bay and Coast.

Sunshine dominates Wednesday’s weather with highs nearly 2 – 5 degrees warmer.

"Spare the Air" Forecast

Q: Mike,

How can I find if it's a "Spare the Air" day at, say, 5 or 6 o'clock in the afternoon? Is there a web site or phone contact I can use?

Thanks for your help.

George @ Streborg1@aol.com

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Hi George,

Good question!

Their (Bay Area Air Quality Management) website is www.sparetheair.org.

Winter Spare the Air Alerts will also be recorded at 1-877-4NO-BURN (1-877-466-2876).

Also, I will still begin listing them here on my weather blog.

Take care,

Mike

December Planets in Southwest Sky

Q: Could you please tell me the planet and star? that we are seeing in the south-west sky these past nights. I thought the planet on the bottom was Venus and do not know for sure. Thank you.

A: Venus, the Moon and Jupiter make a striking sight in the southwestern dusk early in this month. Jupiter descends to the horizon and is harder to see by the end of the month while Venus, the brighter of the two, gets easier.

Hope this helps. Thanks for asking.

Mike