NOTES ABOUT SOUTHERN CALIFORNIA WEATHER & CLIMATE
© 2000-2021 Gary Valle'. All Rights Reserved.
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forecasts and warnings.
|January 2009||Jan. 26 - Unpredictable
Weather? Two periods of rain were recently forecast in Southern
California -- one from Wednesday into Saturday, and another
from Sunday evening into Tuesday. Model projections varied from day
to day and run to run. At one time it looked like the Los Angeles
area might get about an inch or rain out of both systems. So what
Jan. 20 - Ten Consecutive Days with Highs in the Eighties. Rain on the Way. Including today, Los Angeles has enjoyed an unprecedented ten straight January days with highs in the eighties. In the yin yang of weather, the western half of the U.S. has been enjoying unusually warm temps, while the eastern half of the country has shivered.
Dec. 25 - Storm
Misses Los Angeles. Trough Producing Some Rain & Snow.
A Pacific storm system -- which at one point was expected to be
the wettest of the rain season thus far -- took a more westward
track and skirted the coast of Southern California on Christmas
Eve, generally producing only modest rainfall across the area.
|November 2008||Nov. 27 - Rainfall Records Broken in Southern California.
Rainfall totals for the storm have generally ranged from 1.0 to 2.0 inches
in the coastal and valley areas, with some higher amounts recorded in
foothill and mountain locations. Rainfall records for November 26th were
broken at several locations, including Lancaster, Palmdale, Sandberg,
UCLA, Burbank, Woodland Hills, and San Gabriel. OPIDS Camp, in the San
Gabriel Mountains has recorded 3.29 inches.
Nov. 24 - Upper Low Expected to Drench Southern California. NOAA Releases Winter Precipitation Outlook. HPC projects from one to two inches of rain over a large area of Southern California. NOAA 2008-2009 Winter Outlook indicates an equal chance of below normal, near normal, or above normal precipitation for California.
|October 2008||Oct. 31 - Halloween Showers? Winter
Precipitation Outlook. Downtown Los Angeles (USC) records 0.02 inch of rain.
There's a continuing chance of showers in Southern California through
the weekend. Winter precipitation outlook
with a La Nina flavor -- similar to last year.
Oct. 1 - Clouds, Heat, and then Rain? Downtown Los Angeles records a trace of rain, and a few other stations in Southern California recordmeager, but measurable, precipitation. Front associated with the trough is currently forecast to hold together south of Pt. Conception and could produce some showers in the Los Angeles area.
|July 2008||Jul. 15 - Monsoon Pattern Results in Flash Floods & Debris Flows. Monsoonal flow that began last Thursday has resulted in numerous thunderstorms in the mountains and deserts of Southern California, with flash flooding and debris flows reported in several locations.|
|June 2008||Jun. 20 - Heat Wave Expected to Peak Today. Equatorial Pacific in Transition. Temperatures today at Los Angeles Pierce College in Woodland Hills appear to be running about a degree hotter than yesterday, when a new record high for the date of 109°F was recorded at the campus weather station. Equatorial Pacific SSTs continue the transition to neutral conditions. This TAO section plot of 5-day Depth Average Temperature clearly shows the change in state with a marked increase in sub-surface temperatures, particularly in the far eastern and western equatorial Pacific.|
|May 2008||May 23 - Cold Upper Low Generates Extreme Weather in
Southland. More Wet Weather Possible Today and Tomorrow. The unseasonably
energetic upper level low that replaced our unseasonably strong high
has resulted in dramatic weather in Southern California, including
heavy rain, hail, thunderstorms, lightning, and even a pair of tornadoes
near March Air Force base.
May 17 - Strong Pacific Jetstream Pumps Up West Coast Ridge & Temperatures. Chance of a Shower Next Weekend? Yesterday, Woodland Hills set a new high temperature record for the date of 101°F. Record high temperatures were also recorded at Ojai, Sandberg, Santa Ana, El Cajon, Red Bluff, Redding, Sacramento, Stockton, Modesto, San Jose, Eureka and several other stations in California. Triple digit highs were recorded across much of the interior of the state. GFS, ECMWF and other guidance is suggesting that as the extended Pacific jet collapses, the west coast ridge will retrograde off the coast and be replaced by a trough by Memorial Day Weekend.
May 1 - La Niña Fades as Rain Season Nears End. In it's April 30 ENSO Wrap-Up, the Australian Bureau of Meteorology characterizes Pacific climate patterns as being generally neutral, "with the majority of indicators returning to near-normal levels." We've had only a smattering of rain at Downtown Los Angeles since 0.46 inch was recorded back on February 24. A miniscule 0.01 inch was recorded on March 15, and 0.04 inch on April 2.
|April 2008||Apr. 1 - More Than April Showers? A blustery Spring storm is expected to produce measurable rain over much of Southern California tomorrow. As has often been the case this year, the 12z NAM and 12z GFS are at odds, with the NAM generating less than 0.25 inch at Los Angeles, and the GFS more than 0.5 inch.|
|March 2008||Mar. 30 - Weak Front Dampens Southland. Water Year Rainfall Total Falls Below Normal. Only 0.01 inch of rain was recorded at Downtown Los Angeles (USC- KCQT) the entire month of March, pulling the water year rainfall total more than a 0.5 inch below normal for the first time this rain season.|
Feb. 25 - Pacific Storm Soaks California -- Dumps
More Snow in Sierra. Weather conditions were tough for the Amgen
Tour of California cyclists cranking over Mill Creek Summit
yesterday. The Mill Creek RAWS recorded an average temperature
with winds of 25 mph, gusting to 40 mph, at about the time
the peloton cleared the summit. Since mid-week last week some
Sierra snow sensors have recorded as much as 8 or 9 inches
snow water equivalent of precipitation -- the rough equivalent of
6 or 7 feet of snow. Today's Statewide Summary of Snow Water Equivalents,
provided by the California Cooperative Snow Surveys, reports the
Sierra snowpack at 119% of normal for the date and 101% of the average
April 1 seasonal total.
Jan. 28 - Eight Days of Los Angeles Rain One of Longest
Wet Periods on Record. According to NWS Preliminary Climatology
Data (CF6), Downtown Los Angeles has recorded measurable rain on
each of eight days from January 21 to January 28, 2008. This puts it
in the top six of the station's wettest periods from 1921-2007.
|December 2007||Dec. 31 - Strong Pacific Storm Forecast to Pound State.
Los Angeles will end 2007 with precipitation for the water year
close to normal, and with the Sierra snowpack at about 60% of normal.
However the first week of 2008 may usher in one of the strongest Pacific
storms to affect California in some time.
Dec. 20 - Unusual La Niña Precipitation Pattern in the West. According to preliminary NWS data, Downtown Los Angeles (CQT) recorded 1.24 inches of rain as a result of Tuesday night's storm, bringing the water year total to 3.69 inches. This amount is about 3/4 inch above normal for the date.
Dec. 17 - More Rainfall Forecast for Los Angeles. SREF Ensembles have been trending wetter south of Pt. Conception over the next 36 hours with each run. The 15z run indicates >90% chance of the rainfall total exceeding 0.1 inch in the Los Angeles area for the 24 hr. period ending 7:00 a.m. Wednesday.
Dec. 8 - Los Angeles Rainfall Continues Above Normal. Downtown Los Angeles (CQT) recorded 0.41 inch of rain, bringing the water year total (since July 1) up to 2.44 inches -- still 0.16 inch above normal for the date. Last year at this time only 0.50 inch had been recorded.
Dec. 1 - Los Angeles Rainfall Above Normal? In a November where the other 29 days were bone dry, the 30th was surprisingly wet, with downtown Los Angeles (CQT) recording 0.56 inch of much needed rain. The storm brought the water year total (since July 1) for Los Angeles to 2.03 inches, which is a deceptive 0.15 inch above normal for the date.
|November 2007||Nov. 29 - Waiting For Rain. NOAA Updates Winter Outlook. This morning's 3-day precipitation forecast from the HPC showed no precipitation in our area, but the 09z SREF, 12z NAM, and 12z GFS all suggested the likelihood of at least a little rain in Los Angeles county, and the midday update of the HPC forecast now includes some green here. NOAA released its updated Winter Outlook November 15 and the NDJ outlook for Southern California precipitation continues to be bleak.|
|October 2007||Oct. 13 - Upper Level Low Wetter Than Expected.
An upper level low that was expected to produce only a chance of scattered
showers south of Pt. Conception has resulted in more rain at Downtown
Los Angeles (USC) in an 8 hour period than was recorded in any month
of last year's rain season!
Oct. 9 - Southern California 2007-2008 Winter Precipitation Outlook. NOAA released its initial Winter Outlook for the U.S. today, including a Dec-Jan-Feb precipitation outlook. The precipitation pattern projected for the western U.S. is typical of a La Niña, with an increased chance of higher than normal precipitation in the Pacific northwest and an increased chance of lower than normal precipitation in the southwest.
|September 2007||Sep. 23 - September Storm Socks Southland. Several
Southland locations recorded new rainfall records for the date
on Friday and Saturday. Downtown Los Angeles set a new maximum rainfall
record of 0.40 inch for September 22, exceeding the previous record of
0.15 inch set in 2000.
Sep. 19 - Record Setting September Storm? An unusually cold, deep and energetic upper level low is forecast to affect the area over the next 2-3 days. The system could set new rainfall and temperature records for Downtown Los Angeles (USC) and other Southern California locations.
Aug. 31 - Heat Wave Expected to Continue.
Los Angeles Pierce College in Woodland Hills recorded a high temperature
of 109°F on Wednesday and Thursday, and so far today has reached
a temperature of about 108°F. The hot weather is expected to continue
through Labor Day, along with periods of higher than normal humidity.
Jul. 4 - Driest Water Year On Record. There was
no measurable rain recorded this May or June at Downtown Los Angeles
(USC). The most recent measurable rain was on April 22 when 0.04 inch
of rain was recorded. From July 1, 2006 to June 30, 2007, Los Angeles
recorded only 3.21 inches of rain, breaking the record set in 2001-2002
as the driest year since recordkeeping began in 1877.
|May 2007||May 30 - Driest Year on Record Appears Likely. There's a little drizzle around the Los Angeles area this morning, but it would take much more than a light mist to make up the nearly one foot deficit in Los Angeles rainfall. Los Angeles' rainfall total remains at 3.21 inches for a water year that began on July 1, 2006 and will end June 30, 2007. Normal rainfall would be 15.14 inches.|
Apr. 23 - Wettest Day in Driest Year? Friday's
vigorous system produced 0.50 inch of rain at Downtown Los Angeles
(USC). According to the NWS, this is the latest date in the water year
that Los Angeles has recorded it's first day of 0.5 inch, or more,
|March 2007||Mar. 26 - Cloudy, Breezy & Cool — A Chance of Showers, and Maybe a Thundershower. Some showers around the area. From July 1, 2006 to March 25, 2007 Downtown Los Angeles (USC) has recorded only 2.47 inches of rain. This is 11.04 inches below normal.|
Feb. 1 - July-January 5th Driest on Record. Warm Superbowl
Sunday. Pattern Change Ahead? While some locations in the Los Angeles
area were pounded by heavy showers on Tuesday, with rain rates
on the order of a 0.25 inch/hour, Downtown Los Angeles (USC) recorded
only 0.02 inch of rain. This increased the water year total (since July
1) to 1.50 inches, which is 5.62 below normal, and the 5th driest water
year on record.
Jan. 6 - Wind Instead of Rain. Frigid
End of the Week? El Niño May Have Peaked. So far this rain season passing cold
fronts have stirred up more wind than rain. This was the case again
overnight Thursday. A weakening cold front produced little precipitation,
but its passage generated winds in excess of 80 mph at the Cheeseboro
RAWS near Agoura, and Whitaker Peak RAWS along the I-5 corridor south
of Gorman. Dr. Klaus Wolter's Multivariate ENSO Index (MEI) for
November/December decreased from 1.293 to 0.985. This resulted in
the biggest one-month drop in MEI rank on record for this time of year.
Dec. 8 - Change to More Seasonable
Pattern? MEI Exceeds Strong El Niño Threshold. If the
computer weather models have their way, it looks like some cooler,
wetter weather will be moving into Southern California this weekend.
It's already raining up in the Bay area, and Intellicast composite
radar shows the rain band down to about Pt. Conception. Dr. Klaus
Wolter's Multivariate ENSO Index (MEI) for October/November increased
from 1.03 to 1.29. This moves the MEI above the strong El Niño
threshold, as defined by the index. It is the 5th highest MEI for
all October-November values (since 1950). and is the highest ranked
value since April-May 1998.
Nov. 9 - November Temperatures Soar.
Continues to Strengthen. Slight Chance of a Shower? Woodland
Hills' (Pierce College) high temperature of 101°F on Tuesday was the highest November
temperature ever recorded there. Downtown Los Angeles' 97°F set a
new record for the date, and it was the highest temperature ever
recorded by the station so late in the season. Many other stations
around the area also set new record highs.
Oct. 2 - First Autumn Showers. NOAA
Issues Unscheduled El Niño Advisory. TAO/TRITON Moorings
Vandalized. The first
widespread measurable rain of the 2006-2007 rain season moved into
Southern California yesterday, and continued overnight. In an unscheduled
advisory, issued September 13, 2006, NOAA announced that El Niño
conditions had developed in the tropical Pacific and could strengthen
into a moderate event by winter.
Sep. 14 - A Few Sprinkles Around Southland. MEI Exceeds El Niño Threshold. A shortwave wrinkle in a broad upper trough over the West, associated vorticity, and an 80 kt. jet max nosing into Southern California combined to produce a few showers in the area this morning. Dr. Klaus Wolter's Multivariate ENSO Index (MEI) for July/August increased to 0.75, and moves the MEI well above the weak El Niño threshold.
Aug. 3 - Record July Heat. New El
Niño Developing? This
July you didn't have to run an ultramarathon in Death Valley
to experience extreme heat. According to the NWS, Pierce College
in Woodland Hills recorded a new all time high temperature for
that station of 119°F.
This was the highest temperature ever recorded at an NWS observation
site in Los Angeles County. Triple digit highs were recorded at
Pierce College a record 24 days of July.
|July 2006||Jul. 3 - June Hot -- Rest of the Summer
Hotter? Based on (preliminary) climate data for Burbank's Bob
Hope Airport from the NWS, the average daily temperature was more
than 7 °F higher this year than last. In June 2005, only 2 days
recorded a high temperature of 90°F, or above, and the highest
temperature recorded was only 91°F. This June, 13 days saw the
thermometer hit 90°F or above, and the highest temp was 102°F.
Jul. 21 - Heat Wave Continues. New El Niño Developing? However you want to look at it, it has been a hot summer. Based on (preliminary) NWS climate data for Burbank's Bob Hope Airport, June was hot, and the first 20 days of July have been even hotter. At times, higher than normal humidity has increased the discomfort. The NWS climate data for Bob Hope Airport shows that, on average, July has been nearly 6°F warmer than June, and about 6°F warmer than normal. In June the average high temperature at Burbank Airport was 87°F. So far this July it has averaged 94°F.
Jun. 9 - Marine Layer Produces Some Drizzle. Passage of a weak upper trough has deepened the marine layer and produced some drizzle overnight, and this morning, in the Los Angeles basin and valleys. As of 8:00 this morning, LAX has recorded 0.01 inch of precipitation, and several other stations have recorded amounts ranging from a trace to 0.01 inches.
May 18 - Summer Monsoon, to be Followed by Winter Rain? So far this year we've had eighty degree temps in February, foothill
snow in March, and record rain in April; so why not a Summer monsoon
pattern in May, followed by an unseasonably strong Winter-like
Pacific storm system?
Apr. 5 - Record Rain in Los Angeles -- Record Snow
at Mammoth Mountain! The strong Pacific low pressure system that has
been spinning off the West coast since Sunday is finally moving
onshore this morning. The late season low has been pumping copious
amounts of sub-tropical moisture into the state, resulting in moderate
to heavy rain in many areas, swollen rivers and creeks, and heavy snow
at the higher elevations of the Sierra. According to preliminary NWS
data, Downtown Los Angeles (USC) set a new rainfall record of 1.44 inches
yesterday, breaking the record for the date set in 1921.
Mar. 3 - Series of Systems Forecast
for California. Chance of Showers Monday. Weak La Niña Rebounds. Frontal zone associated
with Pacific low pressure system is working its way through Southern
California this morning. Intellicast.com composite radar from 6:15
shows a mix of light, moderate, and some heavier showers around the
|February 2006||Feb. 4 - It's Official: La Niña
is Back. Los Angeles Rainfall Below Normal. Thursday the NOAA
Climate Prediction Center announced the official return of La Niña.
According to NOAA, "sea surface temperatures have met the operational
definition of La Niña for the November through January period." To
qualify as a La Niña, the Oceanic Niño Index (ONI) must
fall to at least -0.5 degree C.
Feb. 16 - Winter Returns. Temperatures Drop, Chance of Rain... and Snow. Monday, Los Angeles (USC) recorded a high temperature of 86°F. Yesterday the high was only 61°F, a drop of 25°F over two days. Accompanying the return of cool temperatures is a chance of rain, and a chance of ending our streak of rainless days at 33 or 34 days. The last measurable rain at Los Angeles (USC) was 0.10 inch on January 14. The NWS climate report for Los Angeles (USC) for February 15 indicates that we've had 4.95 inches of rain since July1, which is 4.14 inches below normal.
Feb. 20 - A Little Rain, a Little Snow. La Niña Starting to Fade? What a difference a week makes! Last Sunday high temperatures around the Los Angeles area were in the mid-eighties, with t-shirt and shorts weather in the mountains. Following a rainy Saturday night, this Sunday dawned partly cloudy and cool, with a dusting of snow atop the higher foothills, and several inches in the mountains.
Feb. 25 - Pacific Storm Has Potential to Produce Excessive Precipitation. A strong Pacific storm system is headed for Southern California, and has the potential to produce very heavy precipitation, particularly on south to southwest facing foothill and mountain slopes.
Feb. 28 - Pacific Storm Drenches Southland. Chance of Showers Friday. A strong Pacific storm system drenched Southern California yesterday and overnight, behaving more or less as forecast and producing 2-3 inches of rain in the coastal and valley areas, and higher amounts in the mountains.
|January 2006||Jan. 4 - Fast Moving Front Soaks Rose
Parade. Strong Winds Blast Southland. A fast moving cold front associated with a Pacific
storm system roared through the Los Angeles basin Monday resulting in
rain on the Rose Parade, and heavy rain and strong winds in many areas.
The LADPW rain gage at Flintridge recorded 1.03 inches from 7:21 A.M.
to 10:45 A.M., the morning of the parade. JPL's weather station in Pasadena
recorded about 1.7 inches of rain for the day.
Jan. 14 - Showers Saturday, Partly Cloudy Sunday. Is a La Niña Developing? GOES-10 water vapor image from 8:30 this morning shows upper level trough moving onshore in the West with associated baroclinic zone curving down from the Sierra into Southern California. Intellicast.com composite radar from 8:45 shows a band of light to moderate rain associated with the frontal zone as it was moving into the Los Angeles area.
|December 2005||Dec. 1 - Jet
Max Expected to Enhance Sierra Snow. Moist west-southwesterly flow
resulting in rain and high elevation snow from about a Monterey-Mammoth
line, north. An area of enhanced precipitation associated with a jet
max is moving through 130W and appears headed for the central
portion of the state.
Dec. 24 - Eighty Degrees the Day Before Christmas; Chance of Rain the Day After. Cooler temperatures are expected in the Los Angeles area on Christmas Day with areas of fog in the morning, especially near the coast. Clouds should be increasing Sunday afternoon and evening leading to a chance of rain.
Dec. 29 - Back to Back Storms Bring in the New Year. Rain Forecast for Rose Parade. Back to back Pacific storm systems are forecast to pound California over the next few days, and as it looks now, could result in rain in Pasadena on Monday for the Rose Parade. This morning's 5-day precipitation forecast from the Hydrometeorological Prediction Center (HPC) indicates precipitation totals exceeding 12 inches (water equivalent) in the Sierra Nevada and 6 inches in our local mountains. The 12z GFS generates about 4 inches of rain at Los Angeles over the same period.
Nov. 8 - Upper Low Threatens Rain. ENSO Neutral...
For Now. MJO Won't Start. 12z NAM and GFS forecast chance of rain.
In absence of El Niño and La Nina Madden-Julian Oscillation
(MJO) can become an important factor in our weather. Multivariate
ENSO Index (MEI) for Sep/Oct dropped below -0.2 for the first time
since Oct/Nov 2001. Drop into
true La Niña conditions appears possible.
|October 2005||Oct. 15 - NOAA Releases Winter Outlook. Cut-off Low
May Result in Showers. La Niña and the El Niño/Southern
Oscillation (ENSO) not expected to play a role in this Winter's forecast.
Models forecast trough diving into California will cut off into an
upper low centered near San Diego.
Oct. 17 - Cut-off Low Produces Showers and Thunderstorms. Flash Flood Watch in Burn Areas. Energetic cut-off upper low centered WSW of San Diego produced showers and thunderstorms overnight along a line extending from the Coachella Valley through Ontario and the San Gabriel Valley to the Ventura County mountains. Flash Flood Watch warned of the possibility of heavy rain, with the potential for flash flooding and debris flows in burn areas.
Oct. 18 - Cut-off Low Continues to Soak Southland. Strong thunderstorms produced gusty winds, heavy rain and hail. A severe thunderstorm developed near Los Angeles, and tracked to the northwest, producing heavy rain in Burbank, Santa Clarita and the Grapevine. Flash flooding and mudslides were reported in the Burbank and Gorman burn areas. I-5 closed for about 4 hours.
|September 2005||Sep. 20 - Southern California Thunderstorms the Result of Hurricane Max? 0.29 inch of rain at Los Angeles sets new record for the date. Multivariate ENSO Index (MEI) increased slightly from 0.42 in June/Jul to 0.43 in Jul/Aug. Most ENSO forecasts continue to predict neutral, or weakly warm near neutral conditions over the next few months.|
|August 2005||Aug. 15 - Unseasonable Upper Low Results in Thunderstorms. Neutral ENSO Conditions Expected. Diffluent flow aloft resulting from an upper level low off the coast produces isolated showers and thunderstorms over a wide area of the southern half of the state. Multivariate ENSO Index (MEI) decreased from 0.48 for May/June to 0.42 in June/Jul.|
|July 2005||Jul. 4 - Deep Snow and Broken Trees After Big Winter Storms. Downtown Los Angeles (USC) records 37.25 inches of rain for the period July 1, 2004 through June 30, 2005, making it the second wettest rain season on record. Deep banks of snow near summit of Mt. Baden-Powell. Multivariate ENSO Index (MEI) decreased from 0.71 to 0.48.|
|June 2005||Jun. 21 - Unseasonably strong upper level low spinning off the Oregon coast produced some rain and showers in Northern California, and a little snow in the Sierra. Multivariate ENSO Index (MEI) for April/May increased from 0.56 to 0.71. Current ENSO forecasts are mixed.|
|April 2005||Apr. 21 - Downtown Los Angeles records 1.00 inch of rain, increasing the water year total to 37.04 inches.|
|March 2005||Mar. 23 - Los Angeles receives more than an inch rain. Rainfall total for the water year at Los Angeles 35.89 inches, ranking it the second wettest on record, 2.29 inches behind the rainiest of Los Angeles rainy seasons. CNFRC posts report regarding February 17-23 Heavy Rainfall Event. NOAA News Online publishes article about February rainfall event and ocean-atmosphere coupling.|
Feb. 11 - Moderate to heavy rain in areas of Los
Angeles and Ventura counties.
|January 2005||Jan. 4 - New rainfall records for the date set in
Chatsworth, LAX, UCLA, Oxnard, Ojai and several other locations.
Downtown Los Angeles (USC) has recorded 15.45 inches of rain since
the start of the water year, 11.4 inches more than normal.
Jan. 6 - HPC forecasts more than 7 inches of precipitation in the Sierra and the mountains of Southern California over the next 5 days.
Jan. 11 - Upper low responsible for historic and devastating series of January storms is finally moving south and east out of area. The 15 days from December 27, 2004 through January 10, 2005 were the wettest 15 consecutive days in downtown Los Angeles since record keeping began in 1877. Streams in the area approached, and in some cases exceeded, peak flows recorded in the major rain event years of 1938, 1969, 1978, 1983, and 1998.
Jan. 25 - Two weeks of dry, benign weather forecast to transition into a 4 day period of unsettled weather.
|December 2004||Dec. 6 - Cold, northern stream upper low and it's associated
surface low and front produced generally light to moderate rain
from Santa Barbara south to San Diego.
Dec. 24 - ECMWF has been forecasting the development of a relatively strong system off the west coast.
Dec. 26 - Los Angeles area weather SPECTACULAR Christmas Day! Models continue to forecast very heavy precipitation in Central and Southern California Monday afternoon into Wednesday.
Dec. 28 - 24 hour rainfall totals in excess of 6 inches recorded in the mountains of Santa Barbara and Ventura counties. Line of strong thunderstorms extending north from near Malibu produced rainfall rates of more than an inch an hour.
Dec. 29 - Complex of strong thunderstorms results in heavy rainfall in downtown Los Angeles and produces a possible tornado in Inglewood. Los Angeles received 5.55 inches of rain -- the third wettest on record. Burbank, Chatsworth, LAX, Pasadena and several other locations set new rainfall records for the date. Wet pattern expected to continue.
Dec. 31 - Frontal zone moving through the Los Angeles basin produces high rain rates.
Nov. 21 - Upper low over Southern California
results in wind, rain and some lower elevation snow. Portions
of Highway 138 and Interstate 10 were closed, and snow
was reported down to as low as 1000 ft.
|October 2004||Oct. 9 - NOAA released
it's initial Winter Outlook.
Oct. 16 - First of three systems forecast to move through the area over the next few days expected to produce first significant rainfall in Los Angeles since April 18th.
Oct. 22 - Rainfall totals for the period October 16-20 ranged from about 3.0 to 4.0 inches in the lowlands to over 10.0 inches in the mountains. OPIDS Camp near Mt. Wilson recorded more than 17.0 inches for the period..
Oct. 27 - Rain rates in excess of an inch an hour were observed as a cold front moved through the Los Angeles basin overnight.
|September 2004||Sep. 16 - According to Dr. Klaus Wolter in the September 3, 2004 update of the Multivariate ENSO Index (MEI) page, the latest increase of the MEI Index from .454 to .602 "virtually guarantees" weak to moderate El Niño conditions this Fall and Winter.|
|August 2004||Aug. 8 - Mild to moderate El Nino may be in the works.|
|July 2004||Jul. 3 - Thunderstorms in the Sierra and in the Ventura County mountains yesterday afternoon. June 30th was the end of the 2003-2004 water year. Unofficially, downtown Los Angeles (USC) received 9.25 inches of rain, which is about 61% of normal.|
|February 2004||Feb. 3 - First significant precipitation
recorded at Los Angeles (USC) since January 2.
Feb. 17 - Pattern change expected with a transition to a split quasi-zonal flow and an active southern jet stream.
Feb. 25 - Potent Pacific system expected to result in heavy rain.
Feb. 26 - Preliminary 24 hour rainfall totals in Ventura and Los Angeles county valleys ranged from about 2.0 to 3.5 inches, with 5.0 to 6.0 inches, or more in the mountains.
|January 2004||Jan. 6 - Pattern change with drier weather expected.|
|December 2003||Dec. 22 - HPC Precipitation
Forecast for Christmas shows a widespread area of more than
and inch of precipitation. 6 to 10 day and 8 to 14 day outlooks continue
to forecast above average precipitation.
Dec. 23 - Models flip-flop on Christmas forecast.
Dec. 24 - Models turn back to wetter forecast. Satellite photos show a long, energetic fetch of moisture and strong jet taking aim on California.
Dec. 26 - Complex system moves through Central and Southern California Christmas Eve and Day, resulting in very heavy Sierra snow, and rain over much of the Southland. Lytle Creek RAWS recorded over 8 inches of precipitation. Debris flows in Devore, and Waterman Canyon.
|November 2003||Nov. 9 - Southwesterly flow over Southern
California produces little precipitation in the
Los Angeles basin.
Nov. 12-13 - Upper level low with 500mb temps of -23 deg. C destabilizes air mass and circulates "wrap around" moisture into the region. Over five inches of rainfall was recorded by a rain gauge at 96th and Central.
Nov. 26 - Long lead forecast indicates a precipitation probability anomaly of 40% below normal over a large area of Southern and Central California.
|October 2003||Oct. 21 - NOAA has releases 2003-2004
Winter Outlook. Equatorial waters warm to just below El Niño threshold.
Oct. 31 - First significant wet weather of the 2003-2004 rainy season is bad news for trick-or-treaters but good news for homeowners and firefighters battling the wildland fires across Southern California.
|July 2003||Jul. 31 - Monsoonal flow results in scattered showers and thundershowers over much of the southwest. La Nina development stalls.|
|May 2003||May 4. - Very late season Pacific system results in precipitation totals of more than one inch throughout much of Southern California.|
|April 2003||Apr. 15 - Late season Pacific system. Rainfall in downtown Los Angeles (USC) is 0.86 inches above normal since Jul. 1.|
|March 2003||Mar. 16 - Second highest 24 hour rainfall total for Los Angeles since record keeping began in 1877.|
|February 2003||Feb. 12 - One of the driest and warmest
Januarys on record, Los Angeles (USC) set a new precipitation record.
Feb. 26 - Rainfall in downtown Los Angeles (USC) 0.24 inch below normal since Jul. 1.
|January 2003||Jan. 6 - Strong offshore wind event produces
hurricane strength wind gusts. First few days of January
unseasonably warm and dry.
Jan. 27 - What happened to El Nino? Outlooks continue to forecast wetter than average weather for Southern California.
|December 2002||Dec. 1- Wandering upper level low.
Dec. 13 - NOAA releases latest Winter Outlook. Series of Pacific systems expected to bring very wet weather to Northern and Central California.
Dec. 19 - Second of a week long series of storms slams into the west coast.
Dec. 21 - Cold upper low tracking southeast towards Southern California coast with NWS radar indicating strong convection and precipitation.
Dec. 24 - Medium range models suggest a shift in storm track to northern California andPacific Northwest.
Nov. 7 - Angeles National Forest is
closed due to extremely dry conditions and the resultant fire
danger. Large areas of the western U.S. are experiencing drought
heavy rain and snow is forecast over the northern two-thirds
of the state.
|October 2002||Oct. 27 - Moderate warm episode (El Niño) conditions. Weak upper level low produced a few sprinkles|
|September 2002||Sep. 4 - Deep trough and hurricane Herman.|
|Jul. 9 -
Driest water year since record keeping began in 1877. Only 4.42 inches of rain
was recorded from July 1, 2001 to June 30, 2002.
|Apr. 15 -
Driest water year to date since record keeping began in 1877.
|Mar. 18 -
Snow closes the Grapevine. Los Angeles (USC) records 0.11 inch of rain.
Seasonal total is 8.57 inches below normal.
|Feb. 18 - Los
Angeles (USC) records 0.29 inch of rain. Seasonal total (since July 1) is 5.42
inches below normal.
|Jan. 7 -
Climate outlook dry for Southern California.
Jan 25. - Los Angeles (USC) more than 3.0 inches below normal rainfall.
Jan. 28 - More rain than expected.
|Dec. 3 -
isolated build-ups around the Southland.
Dec. 10 - Energetic, but moisture-starved, upper low and associated vortex max churn down the state.
Dec. 19- Tightly wound low pressure system off the West Coast.
Dec. 27 - More precipitation forecast for Northern & Central Sierra.
Dec. 29 - Light rain in Southern California. Mixed rain and snow at 9000 ft. in the Southern Sierra.
|Nov. 4 -
Scattered light showers.
Nov. 9 - Unsettled weather.
Nov. 13 - Strong trough resulted in moderate to heavy rain.
Nov. 18 - MRF suggests Northern California might see rain on several days.
Nov. 21 - Rain in northern half of state.
Nov. 24. - Strong system moves rapidly through Southern California.
Nov. 28 - Ensemble forecasts continue to suggest a wet pattern for the West Coast.
Nov. 29 - Weak system is out-of-sync.
|Oct. 30 -
First rain since April 20.
|Jul. 4 -
Jul. 6 - Moist monsoonal flow.
|Apr. 6 - Rain
Apr. 18 - Snowy April in the Sierra Nevada.
Apr. 23 - Record rainfall at Mt. Wilson Apr. 20.
|Mar. 2 - Rain
in Central California.
Mar. 4 - Front stalls offshore.
Mar. 5 - Potent double vortex system results in heavy Sierra snowfall and heavy rain in San Luis Opisbo, Santa Barbara, and Ventura counties.
Mar. 10 - Seasonable weather returns.
Mar. 17 - Green hills & dry weather for St. Pat's.
Mar. 21 - Storm forms off coast and heads to the Pacific NW instead of So. Cal.
|Feb. 4 -
Malibu Hills @ 87 degrees.
Feb. 6 - Cool weather returns.
Feb. 9 - Rain in Central and Northern Cal.
Feb. 11 - Rain moving into So. Cal.
Feb. 12-13 - Major storm. Seasonal rainfall above normal.
Feb. 16 - Wet pattern continues.
Feb. 23 - Showers. Monthly rainfall above normal.
Feb. 25 - Record rainfall.
Feb. 28 - Continuing scattered showers.
|Jan 2. -
Temps in the 80s,64 days w/o rain. Forecast hopeful.
Jan 8. - Rainless stretch ends at 70 days.
Jan. 10-12 - Major storm.
Jan. 15 - Snow showers as low as 2000 ft.
Jan. 26 - Rain for second time in a week.
Jan. 28 - Seasonal rainfall near normal.
|Dec. 4 -
Offshore Cut-off low.
Dec. 13 - Storm flops.
Dec 19 - No rain since Oct. 29.
2000 - Gusty winds and dry weather.
Thanksgiving - Continued fair weather.
Nov. 29 - Rain in No. Cal.
|Oct 11 -
September Long Range Precipitation Forecast. Snow in Sierra, Winter
Oct. 20 - Energetic trough
Oct. 23 - Cut-off low
Oct. 26 - Central Cal rain
Oct. 30 - Rain
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