Newport is known for light to moderate winds, but there are exceptions. Usually our wind is a daytime sea breeze (blowing from the sea to the land). When the land heats up, the air mass above it rises, thereby sucking in cooler air from the ocean. The sea breeze usually starts in the late morning, blowing throughout the day, then dies as the sun sets. This wind is weakest in winter when the land does not heat up as much, and strongest in late summer when it can occasionally reach 25 knots. This wind will generally be stronger towards Dana Point and Long Beach and further offshore than here at Newport. This sea breeze is almost always present, but it can be modified, blocked or reinforced by other wind systems.
Most of our strong winds are caused by pressure systems. Low pressure systems are storm centers which can generate southerly or westerly wind systems, and can exceed 40 knots during the winter months. High pressure inland can generate an easterly Santa Ana condition (especially in the fall) with winds exceeding 60 knots.
Fog can be a problem in the early winter when it is often very thick. The fog usually forms offshore and then blows in slowly to blanket the If you are overtaken by fog, it is your own fault because you could have seen it coming if you were watching out to sea. The following is a seasonal breakdown of the kinds of weather you can expect in the Newport area.
July, August, September
Winds will generally be light and variable at night. In the early morning hours the breeze will be south easterly. Slowly clocking towards the west and building in the afternoons, it may reach 20-25 knots on occasion. If the winds clock all the way to the west, they will usually persist well after sunset, especially offshore. About half the time, however, the winds will hold south of west and remain less than 10 knots. This wind will usually die by sunset. Night and morning low clouds are likely with this southwesterly wind pattern. Occasionally, a tropical storm off the Mexican coast will move far enough north to affect our local weather. Warm humid weather, with higher and thicker clouds than normal, indicate this condition. Commonly, the storm itself will dissipate before reaching our latitude, leaving only heavy surf on our south facing beaches. Very rarely will the storm itself reach us with rain and high winds.
October, November. December
Wind patterns will be similar to summer, but wind strengths will be much lighter. Fog may form offshore and move onshore with the light sea breezes. Storm fronts will begin to reach down the coast and will probably bring some rain by the middle of the period. Santa Ana winds will occur, usually just after the passage of a storm front. Daytime winds will be lightest in December when Santa Anas and storms are not present.
January, February, March
This is usually the storm season in southern California. Rain, with high winds, will occur for 1 to 2 days at a time, with usually 2-4 days clearing before the next storm. Please refer to the section on "forms further in this text. High pressure may build for a time to block these storms for periods of days or weeks. Wind under the high will be a southwest to west sea breeze similar to late summer but not as strong, and usually dying by sunset. Santa Anas will be less common than in the fall. Fog or low clouds will occur, but will probably not be the "pea soup" type of fog seen in the late fall. Nightime winds on cold, clear nights will reach 10 knots from the east on occasion.
April, May, June
Usually by spring, storm systems are becoming weak, but one or two can still appear early in the period. Between storms, the airmass over the L.A. Wind will be stagnant, allowing an inversion to form, trapping pollution and dust particles beneath it. These particles provide a platform for water vapor to condense on as the airmass cools at night. Low clouds (3000 feet or less) will then form, causing overcast conditions the next day. The heat of the sun will slowly disperse the clouds in the daytime, but this will be difficult if they are thick since the white clouds reflect most of the heat away. There - 11 probably be several days (or weeks) when the clouds remain over the coast day and night, with daytime clearing inland. Winds under these conditions will usually be less than 10 knots, starting from the south around 10 AM and clocking toward the west, but usually staying southwest and dying before sunset.
Storms
The north Pacific Ocean breeds a near endless succession of low pressure storms which then drift eastward across the ocean, picking up moisture until they reach the North American continent. In the summertime, a large high pressure area remains semi-stationary roughly 500 miles west of San Francisco. This high pressure area blocks the storms from southern California. During the late fall, this "Pacific high" drifts southward, allowing Pacific storms to move farther south, eventually reaching us in southern California. Even so, we are at the extreme lower edge of these storms and receive much less rain than 300-500 miles north of us in the bay area. Three hundred miles further south, Baja California receives virtually no rain from these storms and so is a desert. Because we are at the edge, it is very difficult for forecasters to predict if a given storm will reach us or dissipate first.
Usually the storm center itself will pass well north of us with only the trailing cold front affecting our weather. Twelve to 24 hours before the front reaches us, high, wispy "mare's tails or cirrus clouds will appear, gradually thickening and perhaps producing a ring around the sun or moon. Within several hours these cirrus clouds will form a sheet of high clouds called a cirrostratus layer. This layer of clouds will then thicken and lower, gradually obscuring the sun. The wind will back to the south or southeast, and build. lf the storm is vigorous, these pre-frontal winds can exceed 30 knots in Newport, but they are normally much less.
As the front gets closer, the clouds will get lower and darker toward the west and rain will begin. These rain clouds are called nimbo-stratus clouds (nimbus means dark and stratus means a sheetlike cloud). Rain will fall steadily for 6 to 12 hours until the front passes, then will turn to showers with broken clouds visible in between. The wind will shift, sometimes abruptly, to the west or northwest and build as the front moves on. These "clearing westerlies" are usually stronger than the pre-frontal southerlies, reaching 40 knots or more.
The sun will now appear along with white puffy clouds called cumulus clouds (cumulus means column), which will become fewer as the front moves farther away.
The above narration is an ideal case. Most of our cold fronts behave like this, but there are variations. Sometimes the storm center will stall offshore, sending band after band of clouds with rain, followed by brief clearing, with more rain following. One clue that thi is happening will be that the wind does not shift to the west, but remains southerly. Sometimes several storms will hit back to back, with little or no clearing in between fronts bringing off and on rain for 4 or 5 days at a time.
Post-Frontal Squalls
The airmass behind the cold front is usually unstable and can sometimes produce squalls and thunderstorms even after the skies have cleared. These post-frontal squalls will be isolated and widely scattered, but if they do hit, they can pack violent winds (exceeding 60 knots), heavy rain or hail, and sometimes even waterspouts. If you go sailing in the clearing sunny weather behind the front, be sure to keep a watch out toward the west for a large, dark cloud with the darkness beneath it extending all the way to the surface. This is a nimbocumulus cloud, and if it is heading toward you, head for the dock and/or be ready to luff or lower your sails quickly. At the very least you are going to get soaked.
These squalls usually pass within 6 hours of the westerly windshift that marks the cold front's passage, so consider postponing your sail until after then. Although the weather may clear during the first 12-24 hours after & storm, it is not advisable to go out sailing during this time. The unpredictable nature of the airmass and heavy winds make sailing Shields dangerous during this condition.
Santa Anas
Santa Ana winds can occur any time of the year, but are most prevalent from September through February. This condition results from a local high pressure area that forms inland over Nevada or Arizona, forcing the surface air to flow over the Mojave desert and up the backside of our coastal mountains. As the air rises, it loses all its moisture, and as it travels down this side of the mountains to the L.A. basin, it is heated by compression. It reaches us QS a strong, dry, warm east to northeast wind, sometimes extending offshore to the Channel Islands. Normally it is stopped at the coast by the westerly sea breeze. Often, the Santa Ana and the sea breeze will fight it out at Newport with the easterly wind winning for a while, then the westerly, producing abrupt wind shifts.
Santa Anas are a dangerous wind for several reasons. First, the weather is usually warm and sunny, so people tend to think it would be good sailing weather. Second, at the base the cliffs block most of the winds, so the wind speed meter tells a false tel. It can be (and usually is) dead calm at the dock, but blowing 40 knots on the other side of the bay. Third, the winds are extremely shifty and can cause violent, unintentional jibes and tacks. Fourth, the winds can be very gusty, going from near zero to as much as 60 knots in seconds. Lastly, the winds are blowing from a different direction than normal, so the areas people tend to think of as sheltered and safe are suddenly completely the opposite (the best examples of this are the normally sheltered coves along the "front side" of Catalina).
Fortunately, the onset of Santa Anas can usually be predicted by the weather service. If the forecast calls tor east to northeast winds, especially below the canyons, this means a Santa Anal Often, if a fast moving front passes through, with rapid clearing behind it, it could mean a high is forming and will be followed by a Santa Anal Once formed, a 8anta Ana condition can last as long as a week. However, the strongest winds will usually occur at the onset and rarely last more than 24 hours.
As a skipper, you should be extremely careful about sailing when a Santa Ana condition exists. As a general rule, don't go out unless you know the wind in the turning basin is less than 20 knots and will stay that way. Do not plan on going sailing the first day of a Santa Ana, and it you have any doubt, call the sailing office, rigger or dockmaster first.
Call (714) 675-0503