Cooler temperatures, windy for some

(Cumulus clouds)

A trough of low pressure moving across the Great Basin Region of Nevada will bring more cooling to the southland today.

Temperatures along the coastal plain and valleys will remain in the 60s.

Meanwhile... the trough is also resulting in a fairly strong onshore push which is producing gusty winds over the mountains and deserts.

Gusts up to 50 mph are possible today through early Thursday morning.

More record highs established on Monday

(Cirrus/Cirrostratus)

Record Highs Tied or Broken on Monday, April 28th, 2008:

Downtown Los Angeles:
96 degrees (Old Record: 95 set in 1921)

LAX Airport:
93 degrees (Old Record: 82 set in 1921)

Camarillo:
88 degrees (Old Record: 83 set in 1969)

NWSFO in Oxnard:
89 degrees (Old Record: 83 set in 1969)

Palomar Mountain:
78 degrees (Tied old record in 1996)

Vista:
93 degrees (Old Record 89 set in 1992)

Ramona Airport:
95 degrees (Old Record 90 set in 1992)

San Diego Lindbergh Airport:
88 degrees (Tied old record in 1921)

Ontario Airport:
97 degrees (Old Record 95 set in 1965)

Temperatures will be much cooler the next few days over southern California as northwest flow increases.

Air Quality Awareness Week April 28th-May2nd, 2008

May through September is known as “ozone season”. Ozone and the pollutants that react to form it (NOx and VOCs) can also be carried on the wind to affect air quality in urban and rural areas many miles away.

Typically the highest levels of Ozone is found in the valleys of southern California... especially in the Inland Empire.

[Current and forecast Smog Levels for southern California]

Record Breaking Saturday across the southland

(Coronado/Pt. Loma - December 2007)
Technique: Canvas layer blend

Some record high temperatures that were either tied of broken on Saturday, April 26th, 2008:

Torrance: 90 degrees (Old Record: 87 in 2004)

Camarillo: 95 degrees (Old Record: 86 in 2004)

Oxnard: 91 degrees (Old Record: 83 in 1997)

Brown Field in San Diego County: 87 degrees (Old Record: 80 in 2000)

Santa Ana: 98 Degrees Tied the old record set in 2004

Another record breaking day of heat across the southland on Sunday... as strong high pressure will continue to produce a moderate off shore flow.

Temperatures will likely approach the century mark in inland portions of the coastal plain and valleys.

Forecast high for Downtown LA on Sunday is 100 degrees.

Want some relief... head to the beaches where temperatures will be in the 70s and 80s.

Southland Drought Monitor

Much of the southland currently is experiencing normal drought conditions except for portions of the OC and IE (where abnormally dry conditions exist).

Record Heat this weekend

(Santa Monica)

High pressure aloft will result in record to near record heat across the southland this weekend with the warmest day to be on Sunday.

Coastal plain will see high temperatures ranging from the 70s at the beaches to the lower 80s to the middle 90s inland areas.

The valleys will reach into the lower 90s to around 100 this weekend.

Normal valley highs are in the middle to upper 70s this time of year.

Breezy to locally gusty winds can be expected through and just below the passes and canyons this weekend.

Warm temperatures this weekend

High pressure over the intermountain west will bring a weak offshore flow to the southland beginning Friday and continuing through the weekend.

Some afternoon temperature readings this weekend will exceed 90 degrees (especially inland portions of the coastal plain and in the valleys.

Along with the warmer than normal temperatures will come locally gusty winds through and below the passes and canyons... which will elevate the fire danger.

Pollen/Allergy update

(California Incline - Santa Monica)

The southland is still experiencing moderate to high levels of pollen.

Predominant Pollens:
* Oak
* Cedar
* Juniper
* Mulberry
* Grass

Outlook through Saturday:
No change in pollen levels expected.

Take care of our planet!

Some things you can do to save the planet at home every day...

1. Save Energy
2. Use less water
3. Reduce/Reuse/recycle
4. Handle Toxics properly

Celebrate Earth day 2008 by getting outdoors, head to the beach, head to the mountains the desert or what ever your favorite place is in the southland!

Weak onshore flow to begin the work week

(La Jolla - December, 2007)

A weak onshore push of air will bring slightly below normal temperatures to the southland through Tuesday.

The marine layer will likely return to coastal plain late Monday night and Tuesday morning... spilling into the valleys of IE and San Diego county during the early am hours.

By mid week:
A weak trough will move just to the north of the southland bring breezy to locally windy conditions to the area along with cooler temperatures.

End of the work week into the weekend:
High pressure will build over the region resulting in well above normal temperatures.

The weak ahead...

(Cirrocumulus clouds)

Sunday:
A trough of low pressure over the western U.S. will ensure another cool day across the southland.

Strong and gusty winds will continue to blow over the mountains and deserts through the evening hours.

Monday through Thursday:
A gradual warming trend is on tap for southern California. Some night and morning low clouds and fog are possible along the coastal plain and valleys with a weak to moderate onshore push.

Friday and Saturday:
High pressure will build over the region... resulting in much warmer temperatures and sunny skies.

U.S. Temperatures Near Average in March as Global Land Temperature Sets Record

From NOAA/NWS:

An analysis by NOAA’s National Climatic Data Center shows that the average temperature for March in the contiguous United States ranked near average for the past 113 years. It was the 63rd warmest March since record-keeping began in the United States in 1895.

The average global land temperature last month was the warmest on record and ocean surface temperatures were the 13th warmest. Combining the land and the ocean temperatures, the overall global temperature ranked the second warmest for the month of March. Global temperature averages have been recorded since 1880.

U.S. Temperature Highlights:
In the contiguous United States, the average temperature for March was 42°F, which was 0.4°F below the 20th century mean, ranking it as the 63rd warmest March on record, based on preliminary data.

Only Rhode Island, New Mexico and Arizona were warmer than average, while near-average temperatures occurred in 39 other states. The monthly temperature for Alaska was the 17th warmest on record, with an average temperature 3.8°F above the 1971-2000 mean.

The broad area of near-average temperatures kept the nation’s overall temperature-related residential energy demand for March near average, based on NOAA’s Residential Energy Demand Temperature Index.

U.S. Precipitation Highlights:
Snowpack conditions dropped in many parts of the West in March, but in general, heavy snowfall during December-February has left the western snow pack among the healthiest in more than a decade, with most locations near to above average.

Nine states from Oklahoma to Vermont were much wetter than average, with Missouri experiencing its second wettest March on record. Much of the month’s precipitation fell March 17-20, when an intense storm system moved slowly from the southern Plains through the southern Midwest.

Rainfall amounts in a 48-hour period totaled 13.84 inches in Cape Girardeau, Mo., and 12.32 inches in Jackson, Mo. The heavy rainfall combined with previously saturated ground resulted in widespread major flooding of rivers and streams from the Missouri Ozarks eastward into southern Indiana.

From March 7-9, eight to 12 inches of snow fell from Louisville, Ky., to central Ohio. In Columbus, an all-time greatest 24-hour snowfall of 15.5 inches broke the old record of 12.3 inches set on April 4, 1987.

In the Southeast, a powerful tornado moved through downtown Atlanta on March 14, causing significant damage to many buildings. This was one of 90 tornado reports from the Southeast in March.

Rainfall in the middle of March improved drought conditions in much of the Southeast, but moderate-to-extreme drought still remained in more than 59 percent of the region.

In the western U.S., the weather pattern in March bore a greater resemblance to a typical La Niña, with especially dry conditions across Utah, Arizona, Nevada, and California. March was extremely dry in much of California, tying as the driest in 68 years at the Sacramento airport with 0.05 inches, a 2.75 inch departure from average.

Weekly Drought Monitor

Much of the coastal plain and valleys are currently experiencing near normal drought conditions with the exception of the OC where abnormally dry conditions.

The deserts and mountains currently heave dry to abnormally dry conditions.

Outlook next 5 days...
Only trace amounts expected with some drizzle during the night and morning hours along the coastal plain and valleys.

Reaching the top of the roller coaster of weather Thursday

The southland is currently experiencing a rollercoaster type of weather. One day it's warm and the next day on the cool side of things.

This pattern is expected to continue into next week.

For the short term (through Friday):
Top of the rollercoaster:
...High pressure (currently situated near Salt Lake) will produce a weak off shore flow of warm temperatures on Thursday. Meanwhile... as the high pressure slides to the east and weaken... this will result in a weak onshore push of air late Thursday night and Friday. Resulting in slightly cooler temperatures on Friday. But... the low stratus deck should remain just off shore over the coastal waters... including the islands.

This weekend:
The bottom of the rollercoaster:
A weak frontal system will slide by to just to north of use Friday night/Saturday morning. This bring much more substantial push of cool ocean air over the coastal plain extending inland to the valleys and lower mountain slopes.

An "Eddy" circulation will develop... resulting in a deep marine layer with some locations near seeing sunshine during the weekend.

Additionally... with this flow... temperatures will struggle to get out of the 60s during the daytime hours.

Early next week:
Climbing the rollercoast again:
Warmer temperatures are forecast to return by the early part of next week as atmospheric heights increase.

Warmer late weekend, then cooler for the weekend

(Avalon, Catalina Island - Colorized photo)

Thursday and Friday:
High pressure aloft will be over the western states late this week... bringing warmer temperatures and fair skies to the southland.

This weekend/early next week:
Upper level low pressure will bring cooler temperatures with a return to the gloom to areas west of the mountains... including the coastal plain and most valley locations.

Some areas of over the weekend... may struggle to see any afternoon sunshine.

It will be windy over the mountains/deserts during this time frame.

Onshore flow is producing much cooler temperatures

(Pt. Loma viewed from Coronado)

An upper level low pressure system will deepen over the western states on Tuesday... resulting in much cooler temperatures and widespread low clouds and fog across the coastal plain and most valley locations.

The marine layer is expected to be even more widespread and more dense Tuesday night and Wednesday morning. There's also the possibility of drizzle.

Meanwhile... due to tight pressure gradients... gusty winds will blow over the northern mountains and deserts through Tuesday evening. At times gusts to around 45 mph are possible. This will affect driving conditions along the 5 FWY through the Grapevine, the 14 FWY through Soledad canyon north into the Antelope Valley... and the 15 FWY from the 15/215 Split north into the high deserts.

A weak offshore flow will develop Wednesday night and Thursday with local easterly winds over the mountains and some valley locations. This flow will be responsible for fair skies and mild temperatures.

Another trough is due in by the end of the weekend returning the gloomy weather to the southland.

Transition Day!

(Satellite Image: FOG/Stratus)

A dry cold front will move over the central coast region this afternoon then into southern California late thsi afternoon.

This front will bring northerly winds and cooler temperatures to the region.

An "Eddy" circulation will set up Monday night with bringing a return to the low clouds for most coastal plain locations.

Temperatures on Monday... will be some 15 to 20 degrees cooler for most areas then what they were over the weekend... with even more cooling expected through mid-week.

After a "Hot" Sunday...major cooling trend to impact the southland

(Forecast Graphic Courtesy: NOAA/NWS)

Another day of "Record-Breaking Heat" Sunday as high pressure continues to produce a moderate off-shore flow.

The only difference between Saturday and Sunday... will be some immediate coastal locations... where a seabreeze may keep afternoon high temperatures a bit lower from Saturday afternoon readings.

But... Relief is on the Way!!

A trough of low pressure is forecast to move over the Pacific northwest (knocking down the high pressure ridge)... this in return will shift the prevailing wind flow from an offshore to an onshore flow by late Monday afternoon.

Temperatures will on average lower 10 to 20 degrees on Monday from Sunday's readings.

The even more cooling expected through mid week along with the marine layer making a return to the coastal plain and even spreading into many of valley locations.

Heat Wave arrives...

An upper level high pressure system combined with a moderate off shore flow will continue to bring very warm temperatures to the region through the weekend.

Temperatures will likely approach or exceed record levels... especially in the inland areas of the coastal plain, valleys and mountains.

Some inland portions of the coastal plain and valleys will be in the 90s today (Saturday) with slightly cooler temperature expected on Sunday as the high pressure begins to lose it's grip on the southland.

Gusty northeast winds will blow this morning...then diminish this afternoon over the valleys and mountains with the strongest gusts through and just below the passes and canyons near the foothills.

This will likely affect driving on the 5 FWY through the Grapevine... The 14 FWY through Soledad Canyon... and the 15 FWY through and just below the Cajon Pass.

Weekend heat wave update

High pressure over the intermountain west... will be responsible for a hot weekend in the southland.

The highest temperatures will occur on Saturday...then slightly cooler temperatures at the high pressure are and offshore flow begins to weaken.

Some forecast high temperatures for selected locations...

Downtown Los Angeles:
89 degrees/ Record: 97 set back in 1888

Long Beach:
88 degrees/ Record: 90 set back in 1958

Anaheim:
90 degrees

Riverside:
96 degrees/ Record: 95 set back in 1988

Hemet:
96 degrees

Thermal:
96 degrees/ Record: 100 set back in 2000

Palm Springs:
95 degrees/ Record: 101 set back in 1990

Burbank:
92 degrees/ Record: 93 set back in 1946

Woodland Hills:
94 degrees

Ojai:
92 degrees

Additionally... breezy to locally gusty winds are possible through and below the passes and canyons... especially Saturday morning.

Hot temperatures by the weekend

(Surface Map - 5AM/pdt, Sun. Apr 13th forecast)

High pressure over the interior west will produce a fairly strong offshore flow Friday through Sunday over the southland.

This will result in very warm temperatures... temperatures nearing 90 degrees along inland portions of the coastal plain and in the middle 70s to around 80 at the beaches on Saturday.

Forecast high for mid city LA on Saturday... 88 degrees.

Some favored valley locations (such as the western San Fernando valley and the IE) will reach into the lower to middle 90s Saturday).

Gusty winds below the passes (especially northern portions) will likely develop Saturday morning then diminish during the PM hours on Saturday.

A bit cooler temperatures are in the forecast for Sunday... as the ridge begins to break down and move east.

Mini heat wave developing by the weekend

High pressure is expected be centered over southern Idaho by Saturday morning. This will produce an off shore of warm, dry air over the southland beginning Friday and continuing through the weekend.

Temperatures are expected to peak out on Saturday...before dropping a few degrees on Sunday.

Widespread 80s are expected on Saturday over much of the coastal plain and valleys... except the beaches where temperatures will remain in the upper 60s to the middle 70s.

Some favored valley locations such as Woodland Hills and Hemet will rise abover the 90 degree mark on Friday and Saturday.

Warm spring weather late week/weekend

High pressure is expected to be positioned just east of Boise, Idaho Friday night/early Saturday.

This feature will produce a moderately strong offshore flow (for this time of year) here in southern California.

This will result in potentially near record breaking high temperatures on Friday and Saturday with a slight cool down as the high pressure breaks down and moves east into Wyoming Sunday and Monday.

Some forecast high temperatures on Saturday...

Downtown Los Angeles: 83

Long Beach: 82

Avalon: 79

Anaheim: 85

San Diego (downtown): 74

Pasadena: 88

Woodland Hills: 90

San Bernardino: 86

Hemet: 88

This will likely be the warmest temperatures that we'll see until July... as typically were heading into gloomy time of year... May Gray... June Gloom type of patterns!

Seasonal pollen update

(Flowering Plum Tree)

Much of the southland is still experiencing moderate to high pollen levels.

The primary culprits are...
- Mulberry

- Ash

- Walnut

- Cedar/Juniper

Strong northwest flow will continue the gloom

A deep marine layer associated with the cool NW flow will continue the "June Gloom" like weather pattern from the coastal plain inland over the valleys and lower coastal slopes during the nights and mornings with only partial afternoon clearing expected through Tuesday.

An upper level trough of low pressure will bring a small chance of light showers to the region beginning Tuesday night and part of Wednesday.

Looking ahead to the end of the week...
High pressure will bring a return to fair and warm weather to the southland.

Cool, northwest flow to continue through the weekend

"June" gloom like pattern to persist through the weekend as southern California is under the influence of a northwest flow.

There will be some brief peaks of the sun during the afternoon hours... but overall skies will be clouds with fog or haze through Sunday.

Along with the "gloom" will come a risk of some drizzle during the night and morning hours.

Due to the clouds/northwest flow... temperatures will remain only in the 60s during the daytime hours.

Not the best weekend to head to the beach.

Increasing "gloom" through the weekend

(SoCal fog satellite imagery)

An increasing marine layer/onshore flow will bring low clouds...fog and local drizzle from the coast inland to the valleys and coastal slopes this weekend.

Only partial afternoon clearing is expected... with some areas along the coastal plain remaining cloudy throug the afternoon hours.

Temperatures will be on the cool side this weekend... due to the marine layer in place.

Looking ahead to next week...
Another trough of low pressure may bring a few light showers to portions of the southland Tuesday into Wednesday.

Probably only Trace to a few hundreth of an inch at the very best.

Fair weather pattern to resume

(Hermosa Beach Pier at night)

Dry northwest flow aloft will bring a fair weather pattern to the southland except for a shallow marine layer along the coastal plain through Saturday.

A weak ridge will bring warmer temperatures on Friday then a few degrees cooler on Saturday as the flow becomes weakly cyclonic.

There will be a noticable increase in the high clouds on Saturday.

April showers... bring May flowers

(Southern California Doppler Radar Imagery)

*Updated at: 4:23pm/pdt, Wednesday, April 2nd, 2008

A weakening Pacific low pressure system will move eastward over the southland tonight/early Thursday morning.

This will result in light to moderate rain or rain showers along SoCal's coastal plain and valleys and few inches of snow over the higher terrain (above 6,000 to 6,500').

Forecast rainfall amounts:
Coastal plain and valleys: 0.10 to 0.35"
Mountains and adjacent foothills: 0.10 to 0.50"
(locally higher amounts over favored south/west facing mountain slopes/foothills)

Fair and warmer weather will likely return Friday and Saturday... before another trough brings cooler temperatures Sunday and early next week.

Rain still in the forecast for mid-week

(Infrared Satellite Imagery)

A storm system over the eastern Pacific is still forecast to bring light to moderate rain to the southland beginning Wednesday and continue into Thursday morning.

Rainfall amounts will generally be in the 1/4 to 3/4" range coastal plain and valleys with 3/4 to 2" amounts mountains and adjacent foothills.

Snow levels will likely lower to around 6,000' over the mountains of Ventura, Los Angeles and San Bernardino counties by Wednesday evening with several inches possible.

Additionally... cold/unstable air aloft will likely be responsible for isolated thunderstorms.

A dry northwest flow aloft will will likely bring a return to fair weather for the second half of the week.