textproduct: Los Angeles

SYNOPSIS

30/523 PM.

Santa Ana winds will continue tonight and Wednesday under mostly cloudy skies. A storm system will move into the area from the south Wednesday with periods of rain through at least Saturday, heaviest Wednesday night into New Years Day.

LONG TERM (SAT-TUE)

30/125 PM.

For the extended, 12Z models continue to exhibit decent synoptic agreement. The overall message will be a continued wet pattern across the area through Tuesday.

Models differ somewhat in the timing of things, but a series of impulses will move across the area through the extended period. At this time, the two best shots of rain will be on Saturday then again on Tuesday, but rain will be possible through the entire period. With either system, light to moderate amounts of additional rainfall are likely. Snow levels on Saturday will be above 7500 feet, but will drop into the 6000-7000 foot range Sunday through Tuesday. So, some accumulating snowfall will be likely at the higher elevations into early next week.

AVIATION

31/0121Z.

At 2315Z at KLAX, there was a shallow surface inversion to 600 feet. The top of the inversion was near 1500 feet with a temperature of 22 degrees C.

Moderate confidence in TAFs. N to NE winds will continue to impact KOXR and KCMA through the period. Then expecting SE winds to develop at the terminals near/north of KSBA after 31/21Z to 01/00Z. VFR CIGs expected through 31/18Z, then lower confidence in forecast of IFR conds between 31/18Z-01/00Z

Isolated -SHRA are possible tonight, then rain chances increase after 31/12Z. The most intense rain will fall sometime between 01/06Z and 03Z/00Z, heaviest south of Point Conception. Slight chance for -TSRA after 01/06Z, especially south of Pt. Conception.

Light to moderate turbulence and LLWS is likely over and near mountainous terrain, especially across Los Angeles and Ventura counties through the forecast period. More widespread turbulence and LLWS likely after 31/18Z.

KLAX...Moderate confidence in the 00Z TAF. -SHRA possible at times tonight, but increasing chances of measurable rain after 31/15Z. Slight chance of -TSRA as early as 01/06Z. High confidence in winds remaining NE to E through 01/00Z, with east wind component up to 10 knots during the afternoon hours. SE winds expected to develop during the overnight period 01/00Z-01/15Z with east wind component potentially remaining near 10 knots. Lower confidence in CIGs/VSBY after 31/18Z.

KBUR...Moderate confidence in the 00Z TAF. -SHRA possible today, but chances for measurable rain increase after 31/16Z Wed. Lower confidence in CIGs/VSBY after 31/18Z.

MARINE

30/856 PM.

Offshore winds linger into tonight and possibly Wednesday morning, and the SCA for the Santa Barbara Channel was extended into Thursday as winds increase from the south as the low approaches. Confidence is higher in widespread SCA level winds from the east to southeast impacting the region (including harbors) as early as Wed afternoon and continuing through at least late Wed night as another storm makes its presence felt across the region. There is a 30% chance for Gale Force Winds during this period, highest chances from Santa Cruz Island and northward. May need a Gale Watch for this time period if confidence increases. A relative lull is possible Thursday afternoon and evening, but a return of SCA level south to southwest wind is likely Friday into Saturday, especially north and west of Point Conception as a cold front moves through the area.

A steep and choppy southerly wind swell will accompany the winds, peaking Wednesday night into Thursday. By Friday, a west to northwest swell will accompany the secondary storm coming through. This swell will be larger and a longer period.

Rain will likely be heaviest Wednesday (New Year's Eve) night through Thursday (New Year's Day). There is a chance of thunderstorms (mainly south of Point Conception) during this period, but confidence is low in timing. Waterspouts, gusty and erratic winds, frequent lightning, and brief heavy rain are all possible with any thunderstorm.

BEACHES

30/856 PM.

Abnormally large tides between 6.8 and 7.5 feet MLLW will occur during the morning hours, roughly between 4am and noon Wednesday through Sunday. Surf heights remain relatively small through Friday, although moderate south-southeast winds and a wind swell from the south-southeast will add a little bit to the water levels. There may be a risk for some minor tidal overflows through Friday, with best chances Thursday and Friday. There is a moderate chance for a Beach Hazards Statement to be issued for Thursday and Friday for a majority of the beaches.

Saturday and Sunday pose more of a threat for moderate coastal flooding as a larger swell from the west-northwest enters the region. While there exists some uncertainty in timing of the highest surf, this would be the best chance for impacts such as shallow flooding of parking lots and roadways, some inundation of harbor walkways, and more significant beach erosion. There is a moderate chance for a Coastal Flood Advisory to be issued for Saturday and Sunday, highest for west facing beaches.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Flood Watch in effect from Wednesday evening through Thursday evening for zones 88-349>358-362-366>382-548. (See LAXFFALOX). PZ...Small Craft Advisory in effect until 10 AM PST Thursday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 8 AM to 1 PM PST Wednesday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect from 7 AM Wednesday to 7 AM PST Thursday for zone 676. (See LAXMWWLOX).