Reading

Gillian - Weather of the San Francisco Bay Region

Bailey - Weather of Southern California

read both by November 10

Reader - 314-316, 335-337, 360-363

Exam Review

hints: Read and follow instructions carefully.

Use complete sentences and use provided format (pertains to writing paper).

Essay: points lost by not hitting specifics as outlined in provided format.

***Try to answer specific question

***A good way to score points is to learn and

know the give-away questions

Website

- plane struck by lighting

Lecture

- Satellite image of sea surface temperatures and upwelling as shown from a radar station in Monterey. The image showing radiation fog in Sacramento Valley due to cooler: denotes transition in season (summer to fall). A calm symbol on weather map denotes that present fog is not advection fog because there is no horizontal movement due to lack of wind. (This can be found of weather map handout for 12 Oct 00 at various locations). Radiation fog in the interior because ground has cooled air to Dew Point. Generally, ground reaches maximum temperature before sunset, and minimum temperature before sunrise.

Environmental Lapse Rate:

the vertical changing in temperature during a change in elevation. On average it is 3 degrees per thousand feet. For example, at 9:00 am, the temperature in Reno, Nevada is 44 degrees, and the temperature in San Francisco is 63 degrees. Surface weather maps are dishonest because it doesn't show the sea weather. They look like the same elevation, but it's not. Air from Reno should get to San Frandsco as the day progresses. If the air reaches San Francisco, it must get to sea level. To suspect if air is moving up or down is similar to pumping up a bicycle tire. While pumping air into the tire, the spigot is hot; while releasing air out of the tire, the spigot is cold. This is due to compression and increase in pressure. While releasing the air, the molecules grow farther apart.

Santa Ana Winds in the Southern California Coast Range. Diablo Winds, in our region, at Mt. Diablo, or Santana - the devil. Breaks in the Coast Range have very strong winds. The mountains in L.A. are about 10,000 feet and the major canyons funnel the winds. Our canyons produce the same effect, only not quite as strong. These winds are warm and dry which produce a perfect element for fires. This is an important weather type which we will talk about later.

Dry Adiabatic Lapse Rate:

When air moves up or down it experiences a change in temperature, 5 1/2 degrees F per thousand feet if moving from the mountains to sea level. Air sinking compresses and warms at this rate. That is why when the temperature in Reno is 44 degrees, the temperature in San Francisco is 72 degrees.

Jet Stream:

the current where the winds are moving the fastest between the isobars. It is also referred to as the "storm track" due to the cumulonimbus clouds that travel along its path at about 18,000 feet. Clouds move along the jet stream like a conveyor belt. The jet stream can be found all over the globe, though may be weaker in some places. It is also referred to as the Polar Jet Stream. There is one in the Northern Hemisphere and one in the Southern Hemisphere - there is even one on Mars! Jet streams exist anyplace with two cold poles that ate rotating.

500 millibars of air pressure at 18,000 feet in the atmosphere. The highest mountains in the country are about 14,000 feet. The winds on the mountains are much stronger than winds down below. Remember rule of thumb: what level is the weather map drawn at? Look at number 2 on the handout from today -air flows clockwise and parallel around high pressure isobars, and counterclockwise and parallel around the low pressure isobars.