11/1137 PM.
Moderate rain and a chance of thunderstorms will sweep through the area through this morning. Scattered shower activity is then possible this afternoon into Monday morning. Dry and warmer weather is expected the rest of next week.
(tdy-Tue), 12/921 AM.
As of 9 am, cold front is bringing steady light to moderate rain to central and eastern LA counties. Behind the front a cool and slightly unstable air mass will continue to bring scattered showers, mainly north of Point Conception. With daytime heating, there may be just enough instability to trigger some isolated thunderstorm activity, so 10-20 percent chance of thunderstorms looks appropriate for today. Any thunderstorms that do develop could also produce gusty outflow winds, small hail, brief heavy downpours, and isolated waterspouts.
As for winter weather issues, snow levels will drop to between 4500-6000 foot today. This system will likely drop 3-6 inches of snow above 6000 feet. This snow along with southerly wind gusts from 40 to 50 mph are covered with a WINTER WEATHER ADVISORY which includes the mtns of SBA/VTA/LA counties.
It will also be windy behind the front in areas other than the mountains. Most gusts, however will come in just under advisory levels. The exception will be the Antelope Valley foothills where a wind advisory is in effect through this evening.
The front will usher in a grip of cool air and as a result max temps will end up mostly in the lower to mid 60s. These temps are 5 to 10 degrees lower than normal.
Another upper level disturbance with associated vort max will push through the forecast area overnight into Monday. This will be associated with some cooling air aloft, with 500 mb temperatures falling to between -23 to -25 degrees celsius. As result, there will continue to be a chance of showers during this period, especially over the mountains. The best instability will occur in the afternoon hours, so may require a slight chance of thunderstorms.
***From previous discussion***
Dry NW flow will move over the area on Tuesday. It will be a sunny day with weak offshore flow. The sunny skies, offshore flow and rising hgts will allow max temps to climb 4 to 8 degrees. Cst/vly highs will end up in the mid 60s to lower 70s.
(Wed-Sat), 12/324 AM.
Not much excitement in the xtnd.
Look for a little ridge overhead on Wed. An inside slider will work its way down the state line on Thu. Followed by dry NW flow on Fri and Sat.
At the sfc there will be mostly onshore flow on Wednesday. Persistent offshore flow from the north will begin on Thursday while the E/W grad will diurnally shift back and forth from weak offshore in the morning and moderate onshore in the afternoon.
Cannot rule out some coastal low clouds but other than that and some ocnl upper level clouds skies will be mostly clear.
The passage of the inside slider will bring a two day north wind event with advisory level gusts likely through the I-5 corridor and the Santa Barbara county mountains.
Max temps will rise 2 to 4 degrees Wed and then change little on Thu. The offshore push on Fri and Sat will result in 2 to 4 degrees of warming each day and will push coastal highs into the 70s and vly highs into the 80s on Saturday (3 to 6 degrees over normal)
12/1227z.
At 0835Z at KLAX, there was no marine layer or inversion.
Moderate confidence in the TAFs. A cold front will affect LA county through 19Z. Cigs will vary between 015 and 035 through 19Z and then will be SCT-BKN050 for the afternoon and evening. LA county will have -SHRA through 19Z while the rest of the sites will be dry. After 19Z all areas will have a 10-15 percent chc of short lived -SHRA or -TSRA.
KLAX, Moderate confidence in TAF. Rain is expected thru 19Z and cig/vis may be as low at 2SM during rain. Aft 19Z there will be a 10 to 15 percent chc of a short lived -SHRA or -TSRA. SCT-BKN layers from 015 to 035 will persist through 19Z and then become SCT-BKN050. There is a 25 percent chc of an 8 kt east wind component through 17Z.
KBUR, Moderate confidence in TAF. Rain is expected thru 19Z and cig/vis may be as low at 2SM during rain. Aft 19Z there will be a 10 to 15 percent chc of a short lived -SHRA or -TSRA. SCT-BKN layers from 015 to 035 will persist through 19Z and then become SCT-BKN050.
12/747 AM.
For the Outer Waters, moderate to high confidence in current forecast. Through tonight, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels. For Monday through Thursday, high confidence in SCA level winds. On Thursday, there is a 20% chance of GALE force winds.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Through tonight, high confidence in winds and seas remaining below SCA levels. For Monday through Thursday, high confidence in SCA level winds, mainly during the afternoon and evening hours. Additionally, there is a 20% chance of GALE force winds on Thursday.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Through tonight, high confidence in winds and seas remaining below SCA levels. For Monday, there is a 60-80% chance of SCA level winds. For Tuesday through Wednesday, high confidence in winds and seas remaining below SCA levels. For Thursday, there is a 50-70% chance of SCA level winds, mainly across western sections.
Ca, Winter Weather Advisory remains in effect until 11 AM PDT Monday for zones 353-376>380. (See LAXWSWLOX). Wind Advisory remains in effect until 10 PM PDT this evening for zones 381-382. (See LAXNPWLOX). PZ, NONE.
