The winds really cranked up in the typical Santa Ana places Sunday night and continues Monday during the day. The winds will continue to blow Monday night into Tuesday and be nearly as strong as the past 12 to 18 hours have been. Winds of 30 to 60 mph are likely with gusts over 80 mph. Those 80+ mph wind gusts are most likely in the higher elevations.

All this offshore wind has driven the humidity to very dry levels and the fire danger will remain extreme through Wednesday. The wind in the next 24 to 36 hours will really hamper fire fighting operations now going on with the two major fires already occurring. Humidity levels probably will not come up noticeably until Friday.

Here are some of the stronger winds in the past 18 hours.

Fremont Canyon-87 mph
Chilao-87 mph
Malibu Hills-79 mph
Camp 9-73 mph
Mill Creek-67 mph
Leo Carillo-65 mph
Cheeseboro-63 mph
Ontario International Airport-61 mph
Corona Airport-55 mph

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Norbert:

After obtaining Category 4 status yesterday Norbert has weakened to a Category 1 storm Thursday afternoon. Now in reality maybe Norbert never was a Category 4 storm as its strength was based on satellite interpretation. Today a hurricane hunter plane visited the storm and found a weaker storm than even current satellite interpretation would indicate. Makes one wonder if it really was a Category 4 storm.

It still seems that Norbert is headed for the southern Baja making landfall sometime later Saturday morning or early afternoon, probably near San Carlos. Environmental conditions will become even more hostile for Norbert with time, especially with regards to shear. At worse it looks like Norbert will be a weak Category 1 storm and could be an upper end tropical storm. Once Norbert moves into the mainland of Mexico the low level circulation will fall apart quickly. But moisture from Norbert could enhance precipitation over parts of New Mexico and west Texas Sunday and Sunday night.

Western Storm:

It is nice when a plan formed days ago continues to look good today. The big storm developing in the West in the next 24 to 48 hours is still right on track from what I had talked about as early as Monday. The details I posted on Tuesday about wind problems are still in line. The snow I talked about yesterday for Utah is also still right on track. So if you have not read those just got to the previous entries to the right of this column and click the appropriate posting.

As a side note. I am off work Friday through the weekend and will not be posting anything more until Monday. I am off to compete in a singing competition this weekend with the barbershop chorus I am part of, The New Gang on the Corner. We hope to do well. A little R&R never hurt anyone.

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Norbert:

Norbert rapidly intensified, not a surprise, and as of late Wednesday it was an extremely dangerous Category 4 hurricane. A visible satellite picture shows the well developed eye with even a stadium effect to the structure. It also shows the relatively small structure of this intense hurricane.

Norbert will continue to be a major hurricane over the next 12 to 24 hours as sea surface temperatures remain very warm and the upper-level environment is still quite favorable for the hurricane.

After tomorrow, Norbert will turn from moving west-northwest to a more northerly direction tomorrow night then turn northeast and perhaps start to pick up its speed on Friday into Saturday. The AccuWeather.com Forecast Eye Path shows this turn nicely.

Norbert will start to encounter less favorable conditions and weaken with time as sea surface temperatures drop off and a strong upper-level trough over the Southwest states starts to bring shear. The big question, and one not easily answered yet, is how quickly will this weakening take place before Norbert impacts the southern Baja. Odds are that it would still be a hurricane when it comes inland in the Baja, but beyond that, it's really too early to tell the intensity. This will mainly depend on the impact of the northern trough to the structure of Norbert. Adding a little to the uncertainty is the fact that there are still some models that really slow down the forward progress of the storm as it nears the Baja coast, perhaps suggesting that the upper-level center separates from the lower circulation. All interests across the central and southern Baja should continue to monitor the progress of this storm closely.

Big Western Storm:

My long post of yesterday for this storm still looks right on target. So if you did not catch it the first time, just click here. A little additional information for you. A significant snow is likely Saturday into Saturday night for the Wasatch range from north to south with at least 8 to 16 inches likely. It will even snow down to the higher plateau regions with snow expected in Cedar City and Salt Lake City and other valley locations of northern Utah with accumulations possible.

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Two main subjects today, Hurricane Norbert and its possible threat to the Baja, and a strong, cold storm developing in the West bringing a significant wind event by Friday and the weekend.

Norbert:
Norbert continues to strengthen in the eastern Pacific over 500 miles south-southwest of the southern tip of the Baja. As of late afternoon on Tuesday Norbert had sustained winds of an estimated 85 mph.

The outlook for Norbert is for additional intensification over the next 24 to 48 hours as it moves over very warm water with little shear. Norbert seems likely to obtain Category 2 status, and may even get to a 3 by Thursday. The track will take Norbert west and northwest for another day or two before turning more north. The big upper-level trough developing in the Western U.S. by Friday and Saturday will more than likely turn Norbert to the northeast. Though all the models are not in agreement here, there is at least a decent chance that a weakening Norbert could threaten the southern third of the Baja by Saturday. Since this is a big vacation area, all people planning on going to Baja should keep a close eye on the developments over the next couple of days. Norbert is not likely to be as strong coming ashore as it will be on Thursday. But it certainly could be a hurricane.

The Big Change - Wind and Much Cooler Temperatures:

Yesterday my post was on the potential for a moderate to moderately strong Santa Ana wind event, the first of the season, for Southern California. I wanted to give a more detailed forecast for winds across much of the state from Friday through Monday now.

Before I get to that, there will be other big changes in the West because of this storm. This will include the coldest weather of the season for the Great Basin and the Rockies, the first substantial snow of the season for the Utah and Idaho mountains, and widespread snow in parts of Wyoming and Montana.

Now to the subject at hand. Yesterday I surmised that the model of choice was more than likely going to be the European with the deep, cold low farther west than the GFS had. This is now looking likely. This will delay the STRONGEST Santa Ana winds in Southern California to late Sunday, Sunday night, and Monday morning. But there are likely to be strong winds elsewhere before that. Below are the highlights.

-Strong winds Friday of 30 to 60 mph with higher gusts are likely in the mountains of Los Angeles, Ventura, Santa Barbara and San Bernardino as well as the upper deserts. This will be caused by a strong upper-level jet moving overhead along with onshore pressure gradients of up to 10 mb. Expect areas of blowing sand and dust.

-Winds of 20 to 35 mph with higher gusts are likely on the Central Coast up to the Bay Area and in the Central Valley Friday and Saturday. Stronger winds are likely in the higher elevations. In the big farming area of the Central Valley, the winds are likely to also produce local dust storms reducing visibility.

-Santa Ana winds in the mountains and below passes and canyons in Southern California set in at some point Saturday or Saturday night. The strongest winds probably occur when the pressure gradient is the strongest, Sunday night into Monday morning. At least expect the strongest winds to be 30 to 60 mph with higher gusts.

-The fire danger over much of central and Southern California will rise to extreme levels by Friday and continue through Monday.

-Today, it's in the 90s in much of the inland areas of Southern California; by Friday it will be mostly low to middle 70s, 20 to 30 degrees cooler than today.

-This will NOT be a hot Santa Ana, at least for a time, west of the mountains in Southern California. The cold storm aloft to the east will make this a cool Santa Ana through Sunday. As that storm moves northeast by Monday and Tuesday, noticeable warming takes place with Monday being a much warmer day with 80s to near 90 and even warmer temperatures with less wind on Tuesday.

These are the highlights. I will continue to monitor this situation and give additional updates as the week progresses.

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October typically is the month that starts the Santa Ana season in California. Santa Ana winds can cause major problems from wind damage to travel problems and bring extreme fire danger. In fact some of the worst fire events occur in California during Santa Ana wind events.

This coming weekend may see the first significant Santa Ana winds of the season in central and Southern California. A strong upper-level trough develops in the Great Basin Friday into the weekend with a closed, cold low developing on the southern end of the trough. This in turn lets high pressure build in behind the trough setting up the offshore flow. The problem I face right now is deciding on when the winds could develop and how strong they might be. While all the computer models show the same general overall pattern developing, they do differ on the details. As always the devil is in the details.

As an example, one can see the difference in the position of the upper-level low by 4 a.m. Pacific time Saturday between the GFS and the European.

GFS:

European:

The GFS is farther east with the closed low, in central Utah, than the European with its low over south-central Nevada. The Canadian model is also west with the low over southern Nevada. Why is the position of the low important? Because the farther west the low is the slower the winds will develop. The upper level low has to be able to move east to allow the surface high to build. If the European and Canadian are more right, then the Santa Ana winds would not start until Saturday night or Sunday. If the GFS is more correct the winds could develop 12 to 24 hours earlier.

Unless all models are wrong, some sort of Santa Ana event will occur, at least a moderate wind event. But timing is the problem this far out and the timing issues may not be resolved for another couple of days. But all interests should keep watching as a Santa Ana wind event could bring an extreme fire danger and threat.

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