Onshore flow to give way to a weak off shore flow late in the week

(October 30th, 2007 - Sunrise)

Wednesday...
An onshore flow will bring morning low clouds and fog to the coast and in the valleys of the IE and San Diego...otherwise look for mostly sunny skies and seasonal temperatures for Halloween.

A weak "Sundowner wind" is possible Wednesday evening along the south coast of Santa Barbara county. Local gusts to around 20 mph are possible.

By the weekend...
A weak off shore flow will bring warmer temperatures and locally breezy conditions to the southland Friday and Saturday. The strongest winds will likely occur Saturday morning through and just below the passes and canyons. Gusts in these areas may approach 40 mph.

HAPPY HALLOWEEN!

Cooler temperatures next couple days

Weak disturbances will bring cooler temperatures to the southland through mid-week
Most areas of the coastal plain and valleys will see high temperatures in the 70s except in the lower to middle 80s far interior valleys.

Later in the week... high pressure will build into the Great Basin. This will produce a "weak" Santa Ana wind Friday into Saturday.
But... no where near the level of winds that the southland experienced earlier last week.

A few showers possible through Tuesday morning

Monday through Tuesday...
Low pressure will bring a small chance of light rain or drizzle to much of the southland beginning Monday afternoon over Santa Barbara county and the L.A/Ventura county mountains then spread across the remainder of SoCal (except for the low deserts) Monday night...then lingering across the far south/eastern portions of the southland Tuesday.

Most areas will recieve one tenth of an inch or less... with some areas only recieving a Trace to 0.01".

Later this week into next weekend...
High pressure over the Great Basin... is still expected to bring an off shore flow to the southland. Right now... it appears this will not be a strong as the previous Santa Ana wind event... but gust to around 50 mph are possible through and just below the passes and canyons.

Temperatures will warm into the 80s and 90s across the much of SoCal Friday and Saturday.

It appears... that the strongest winds will peak Saturday morning.

This week...

(Smoke/high clouds at sunrise on Saturday, October 27th, 2007)

Sunday...
A very weak offshore flow will bring mostly sunny skies and warmer temperatures to the southland. Winds will remain light and variable for the most part.

Monday through Wednesday...
A low pressure trough over the Pacific will bring cooler temperatures.
Expect an extensive marine layer during the night and morning hours with possibility of drizzle.

Thursday and Friday...
Mostly sunny skies with seasonal temperatures.

Looking ahead to next weekend...
There is indication that another "Santa Ana" wind event may occur over the weekend... More on that as the week progresses.

A few light showers or sprinkles Saturday?

(Smoky Skies - October 25-26, 2007)

You can thank the remnants of "Kiko" for the increased cloud cover blanketing the southland Saturday.

This may lead to isolated "very" light showers or sprinkles...mainly Saturday afternoon over the coastal plain, valleys and mountain areas.

Only Trace amounts expected.

Temperatures are down and dewpoints are up along with light/variable winds.

...Overall... good weather conditions for the firefighting efforts!

Sunday through much of the new week...
Generally seasonal weather conditions are expected with light winds for the southland.

Air quality problems continue... due to the fires

(Smoky morning - Thursday morning)
Photo Courtesy of Nitsa

Unhealthful air - due to the smoke from the fires across the southland.

It is strongly recommended for all SoCal residents to limit their time outdoors until the air quality improves... which may be several days from now.

Additionally the deserts will see an increase in smoke on Friday and Saturday...due to the windshift to the west/southwest.

Cooling trend and a return to onshore flow by week's end

(Smoke Plumes --Tuesday, Oct. 23rd, 2007)

Upper low pressure approaching from the north will bring cooling temperatures and higher dewpoints for the remainder of this week.

But... a return to an offshore flow is expected by Sunday...as high pressure aloft... once again builds over the intermountain west.

At this time... the temperatures/winds...won't be anywhere as close to the levels experienced earlier this week.

Forecast high temperatures for Thursday/Friday:

Downtown LA:
Thursday: upper 80s
Friday: upper 70s

Oxnard:
Thursday: upper 80s
Friday: upper 70s

San Diego:
Thursday: lower 80s
Friday: middle 70s

Fallbrook:
Thursday: upper 80s
Friday: lower 80s

San Bernardino:
Thursday: lower to middle 90s
Friday: upper 80s

Big Bear Lake:
Thursday: lower 70s
Friday: around 70

Julian:
Thursday: lower 80s
Friday: upper 70s to near 80

Finally... some relief in sight!

(Satellite imagery of SoCal fires - Courtesy of NASA)

The offshore flow is finally weakening as high pressure over the Great Basin is weakening and moving east.

This will allow more of a onshore flow to develop Thursday and Friday... which will bring cooler temperatures, higher humidities and much lighter winds to the southland.

For the near term (Thursday):
Look for more localized wind gust to around 40 mph...through and just below the passes and canyons...mainly during the morning hours...then diminishing during through the afternoon.

Additionally... air quality across the southland is unhealthful...as smoke from the fires has blanket the region.

It is strongly advised to remain indoors...as smoke make breathing difficult.

As the onshore flow develops on Thursday and Friday...the smoke plumes will move more northeast carrying them northeastward out to the deserts.

Heat and winds

(Smoke Plumes as seen from the visible satellite imagery)

Heat combined with strong Santa Ana winds will make for another rough day for the firefighters fighting the 15 plus blazes burning across the southland.

Like the past couple of days... the strongest winds will occur again through and just below passes and canyons.

In these areas... gusts may exceed 65 mph at times.

Temperatures... reach into the upper 80s and 90s in much of the coastal plain and valleys on Tuesday...with some valley locations reaching the 100 degree mark.

Humidity will be in the single digits in many locations of the southland.

Some improvement in the weather conditions are seen by the end of the week. Cooler temperatures, higher humidity and ligher winds!

Dangerous Santa Ana winds continues...

(Smoke Plumes - Visible Satellite Imagery)

Hot, Dry Santa Ana winds will continue for the next couple days across the southland.

Strong winds (gust to over 60 mph in some locations) combined with very low dewpoints and high temperatures will continue to make for extremely hazardous fire conditions.

Some relief from these conditions is expected beginning Wednesday night and Thursday.

Major Santa Ana Wind Event Sunday through Tuesday

Updated at: 4:40am/pdt, Sunday, October 21st, 2007

Strong Santa Ana winds will continue through Tuesday.

Winds have the potential of gusting to around 80 mph through and just below passes and canyons (especially the San Bernardinos/San Gabriels).

Elsewhere... gusts of 55 to 70 mph are possible through and below passes and canyons.

Gusts to 50 mph are possible along the coastal plain and the coastal valleys...with locally higher gusts in the Malibu and Hollywood Hills.

With the high winds... areas of blowing dust and sand with reduced visibilities to near zero at times...especially interior valleys and in the deserts.

Temperatures will warm significantly over the next couple of days... reaching into the 90s in many areas...with lower 100s in some interior valley locations on Monday and Tuesday.

The high winds/warm temperatures and extremely dry conditions will make for dangerous fire conditions over the southland through Tuesday.

Santa Ana winds Saturday night through Tuesday

***Updated at: 4:38am/pdt, Saturday, October 20th, 2007***


High Pressure will build over the Great Basin and Intermountain the west during the next couple days. Strong/gusty winds will blow across the southland beginning Saturday night and continue through the early part of the week.

Winds (Sunday through Tuesday):
Gusty northeast winds will occur over the region...with strongest gusts through and just below passes and canyons.
It is possible that gusts may approach 80 mph Sunday through Monday morning...especially through and just below passes and canyons of the San Gabriels and San Bernardinos

Elsewhere... gusts to 55 mph possible.

Additionally... areas of blowing dust and blowing sand will likely reduce visibilities to near zero...especially in the deserts and possibly in some interior valley locations.

Humidity/Temperature/High fire potential:
Single digit humidities combined combined with high temperatures extremely dry fuels (dry brush) will make for very high fire danger across all of southern California.

Santa Ana winds this weekend/early next week

(Hollywood Hills - August, 1983)

A moderate to potentially strong Santa Ana wind event is still in the forecast for the weekend and early next week.

High pressure will build over the Great Basing this weekend...resulting in an offshore flow of warm, dry weather from the northeast.

These conditions will bring strong/gusty winds to the much of the southland beginning late Saturday and continuing through at least Monday.

The strongest of the winds are likely to occur on Sunday into early Monday.

With the warm temperatures, strong winds and very humidities... the fire danger across the region will be extremely high.

Fire weather watches have already posted for portions of SoCal for this weekend.

Many locations will see high temperatures in the 80s and 90s on Sunday and in the 90s on Monday.

Wind gusts exceeding 50 mph are likely Saturday night through Monday morning in the mountains/valleys...strongest gusts through and below passes and canyons.

Humidities on Sunday into Monday will be in the single digits through out the southland.

Winds continuing in some locations...

(Gloomy Night - Coronado Bridge)

Winds will continue to be quite strong at times through most of Thursday...mainly through and below passes and canyons...and over most desert locations.

Elsewhere... mostly clear skies are expected.

Temperatures will be a bit warmer on Thursday too.

Looking ahead...
High pressure along with an offshore flow will bring a Santa Ana wind event beginning this weekend and is expected to continue into the first couple days of next next.

Winds are blowing over parts of the southland

(Mojave Wind Farm - Near Mojave)

Strong winds continue to blow across the mountains/deserts of southern California.

The strongest winds will occur through and just below the passes and canyons. in these areas... gusts to 50 mph are possible.

In the deserts gusts to around 45 mph are possible.

Winds are expected to diminish somewhat by mid morning Wednesday over the mountains of Ventura/Los Angeles counties and the Antelope Valley... but will continue through at least early Wednesday afternoon over the western deserts of San Bernardino/Riverside counties and the deserts of San Diego county.

Like on Tuesday... if you are planning on driving in the deserts... areas of blowing sand and dust will restrict visibilities to just a few feet at times...so use extreme caution.

A potentially strong Santa Ana Wind event is on tap for Sunday and Monday. If this occurs... warm, dry and very windy conditions will occur.

STAY TUNED!

Gusty winds for portions of SoCal

(Cumulus clouds)

Several fast moving system will move through California this week.

The primary threat from these systems will be periods of gusty winds...with the strongest winds through and just below passes and canyons of Santa Barbara, Ventura and Los Angeles counties.

The first wind event will occur Monday evening through Tuesday morning with an even stronger wind event Tuesday evening through Wednesday morning.

With this particular wind event... gusts to around 55 mph are a strong possibility.

Additional periods of gusty winds are quite likely later in the week and the weekend... so stay tuned!

The next 24-48 hours across the southland

(San Diego Harbor)

Another wind event for portions of SoCal:

A fast moving storm system will bring areas of gusty north to northwest winds later Monday afternoon over the south coast and mountains of Santa Barbara county...then form across the mountains of Ventura and Los Angeles counties later Monday evening.

The winds will be the strongest through and below passes and canyons...including the 5 FWY corridor through and just below the Grapevine.

Winds are expected to diminish during Tuesday morning...then strengthen once again and become stronger by Tuesday evening.

For the remainder of the southland:
Look for a deep marine layer covering the coastal plain and valley locations during the next 2 days with only partial afternoon near the coast.

Temperatures will continue to average well below the seasonal normals.

Sunday and beyond...

(Santa Monica Beach - July 2005)

Weak high pressure will bring a return to fair and warmer conditions on Sunday.

Meanwhile... A series of weak low pressure systems will bring variable amounts of clouds and a little cooler temperatures during the early part of the week.

Fair and warmer weather will make a comeback towards the second half of the week...as high pressure once again builds over the region.

Fair and warmer weather to return late this weekend

(Desert Sunrise - October 12th, 2007)

Lingering affects of an upper level low pressure system will bring gusty winds Saturday morning to the mountains/deserts along with a chance of showers to far southern/eastern portions of the southland.

A short wave ridge expected move over the region by the second half of the weekend... bringing fair and warmer conditions.

Partly cloudy and cooler weather will make a comeback early next week.

Possibility of showers?

An upper level pessure system will begin to affect the weather along the central coast on Friday... bringing a chance of showers to Santa Barbara county...especially during the afternoon/evening hours.

As the system swings through central/southern part of the state... look for a chance of mainly light rain showers over the southland Friday night with a few rain showers lingering into Saturday morning over the far south/eastern portions.

Rainfall amounts will total less than a tenth of an inch... with some areas may not even see drop of rain.

High pressure will begin to build over the region Saturday night and Sunday bringing warmer and fair conditions.

Onshore flow continues...

(Evening Volleyball game at the beach)

An onshore flow will continue to the morning low clouds and patchy fog on Thursday along with cooler than normal temperatures.

Daytime high temperatures on Thursday will range from the middle 60s to the lower 70s at the immediate coast, middle 70s downtown LA and inland OC, in the 70s to around 80 in the coastal valleys and in the upper 70s to the middle 80s in the interior valleys.

A trough of low pressure will bring a small chance of showers to the southland during Friday night and early Saturday.

At this time... don't expect that much in the way of measurable precipitation with the system.

Gloomy and cool Wednesday

(Gloomy Evening at Hermosa Beach)

A dying cold front will bring a few rain showers to Santa Barbara county on Wednesday.

Meanwhile... an onshore flow will bring clouds to the southland and morning fog...mainly along the coastal plain.

With the onshore flow... southland temperatures will be below the seasonal normals with high temperatures only reaching into the lower 70s in downtown LA.

The beaches will see temperatures in the middle to upper 60s and the valleys in the 70 except lower to middle 80s interior valley locations.

Cooler on Tuesday

Cooler temperatures expected on Tuesday across the southland along with some patchy early morning low clouds and dense fog along some beaches...otherwise look for mostly sunny skies.

High temperatures will range from the upper 60s to the middle 70s at the beaches. upper 70s downtown LA, lower 80s inland OC and in the 80s in the valleys.

Winds will be light under 10 mph.

Sunny/warm on Monday

(Hermosa Beach - September 2007)

Sunny and warm conditions expected on Monday.

Locally breezy through and just below some of the passes and canyons...especially during the morning hours.

Highs will range from the 70s at the beaches, lower 80s dowtown LA, lower to middle 80s inland portions of the OC and in the 80s to the lower 90s out in the valleys.

An onshore flow will return late Tuesday night across the southland and will likely continue through next weekend.

This will bring night and morning low clouds and fog along with cooler temperatures.

Moderate Santa Ana wind event on Sunday

High pressure (as indicated on the above forecast map) will produce an off shore flow of warm, dry air over the southland.

Gusty winds will occur through much of day on Sunday...with the strongest wind gusts through and just below the passes and canyons.

In these areas wind gust may exceed 45 mph at times.

With the dry conditions combined with the gusty winds... this will add up to for dangerous fire conditions across the southland on Sunday... So a Red Flag warning is in effect for the valleys and mountains.

Winds are expected decrease Sunday night into Monday...except a few gust to 30 mph or so are possible through and just below some of the passes and canyons.

A return to a cooler onshore flow is expected during the second half of the week.

1st Santa Ana wind event of the season arrives this weekend

(Santa Monica Beach)

The first Santa Ana wind event will arrive over the weekend.

The off shore flow will bring warmer temperatures and gusty winds over the southland with the strongest winds occurring Saturday night and Sunday.

The strongest winds will likely occur through and just below the passes and canyons...with some gusts exceeding 55 mph at times.

The National Weather Service has already issued Fire Weather Watches and Wind Advisories for portions of southern California.

Gloomy, windy Friday across the southland

(Gloomy Day in La Jolla)

A deep trough of low pressure will bring a strong onshore flow to the southland on Friday. This will result in rather cool temperatures for this time of year...along with extensive clouds and a chance of light rain or drizzle for the coastal and valley areas and some mountain locations.

Along with the deep trough of low pressure will come gusty winds (due to the tight west to east pressure gradient). The strongest winds will occur over the mountains and deserts... but gusts to around 35 mph are possible over the coastal portions of Ventura, LA, Orange and San Diego counties along with valleys of the IE and San Diego county.

As the trough moves out the the area this weekend... a return to warmer temperatures are expected along with moderate off shore flow setting up over the southland...especially on Sunday.

Change in the weather for the remainder of the week

(Gloomy evening at the San Diego waterfront)

A deep trough of low pressure will increase the marine layer across a good portion of the southland through Friday...reaching some of the mountain areas late Thursday night or Friday morning.

Along with the deep marine layer... there will be a slight chance of light rain or drizzle late Thursday night and Friday morning.

It is possible...that some areas on Friday will stay cloudy along with some fog through the afternoon hours.

A tight pressure gradient will form Thursday afternoon and will produce gusty winds over the mountains and deserts Thursday afternoon through Friday evening.

Some mountain and desert locations will likely see gusts at times to around 50 mph.

On Friday... the coastal and valley areas will see highs only in the 60s.

Warmer temperatures are on tap for the weekend... as weak to moderate off shore flow develops.

Another beautiful day for the southland on Wednesday

(Fishing next to the Santa Monica Pier)

Mostly sunny skies on Wednesday.

There will be some patchy morning low clouds and fog near some of the beaches... mainly from the South Bay of L.A. county southward into Orange and San Diego counties.

Daytime high temperatures on Wednesday will range from the 70s at the beaches, upper 70s to the middle 80s inland portions of the coastal plain and in the middle 80s to the lower 90s out in the valleys.

So Cal. History made on October 2nd, 1858

(Off the coast of San Diego county)

Historic weather records show on October 2nd, 1853... Wind, Rain fell on the southland.

The system produce minimal hurricane force winds in San Diego...and Tropical Storm force winds as far north as Long Beach.

Even though the weather records are very limited from that far back... it's thought to be the only known tropical system to directly impact southern California.

A similar system if it was too hit the southland in 2007 would produce $200 million damage.