24/206 PM.
The first storm is moving out of the area but another storm is expected to move in later tonight into Christmas Day. Showers are expected to pater off by early Saturday with dry and warmer weather returning for the rest of the weekend through the middle of next week.
(tdy-Sat), 24/228 PM.
***ANOTHER ROUND OF HEAVY RAIN COMING ON CHRISTMAS INTO EARLY FRIDAY***
A powerful storm that brought up to 10 inches of rain to the mountains today, up to 5 inches of rain elsewhere, and winds gusting as high as 80 mph is starting to move east out of LA County. Some lingering showers are possible this evening, especially along the Central Coast but otherwise dry conditions are expected in most areas through early Christmas morning. It's important to note however that despite the brief respite in rain, area roadways tonight will be in bad shape after today's hammering storm that generated numerous mud and rock slides as well as several inches of water and debris on some roads.
At that point a second system will be on our doorstep with showers and a chance of thunderstorms expected most of Christmas Day. Locally heavy rain is expected during the day and into early Friday morning, especially in the mountains, with rain rates up to a 0.50-0.75 inches per hour possible. Given the amount of water that fell today it won't take much additional rain to generate significant impacts, including additional mud and rock slides through the canyons and dangerous flooding on area roads and highways. Most of the hi res models are indicating another 2-5 inches of rain in the mountains, with locally higher amounts where any thunderstorms develop. Elsewhere additional rain amounts are expected to be less than 2 inches, though again any thunderstorms could locally push that higher.
Showers are expected to become more scattered Friday but most areas should get at least some additional rain through Friday and possible into early Saturday morning.
(Sun-Wed), 24/233 PM.
Not much synoptic agreement on the Sunday upper pattern. But no mdl is showing any rain and hgts a fairly similar so do not think the mdl disagreement will affect the fcst too much. The big news is that for the first time in a while skies will be mostly sunny or at worst partly cloudy. Max temps will bump up 3 to 6 degrees with the sunshine and most cst/vly max temps will be near 65 degrees.
Mdl disagreement worsens on Monday, but at least the ensembles have trended toward the dry deterministic runs and now it looks like Monday will be dry. Max temps will rise another 2 to 4 degrees and most max temps across the csts/vlys will be in the mid to upper 60s.
Roughly 60% of the ensemble members are showing a system arriving around the middle of next week. There's a big spread in the rain amounts with some as high as 2 inches and others indicating little to no rain.
24/2355z.
At 23Z at KLAX, there was no marine layer nor an inversion.
Low confidence in all TAFs through the period. Cigs and Vis will vary frequently as showers moves through the area.
There is a 10-15 percent chc of TSTMs through the period.
Gusty winds will affect the airfields at times through Friday. The winds will generate turbulence over and near to hier trrn.
KLAX, Low confidence in TAF. Cigs and Vis will vary frequently as showers move through the area. There is a 10 percent chc of a TSTM through the period. Good confidence that there will be an east wind component over 10kt through at times through Thu afternoon.
KBUR, Low confidence in TAF. Cigs and Vis will vary frequently as showers move through the area. There is a 10 percent chc of a TSTM through the period. Gusty winds at times will generate periods of turbc and LLWS.
24/252 PM.
A powerful winter storm will continue to impact the coastal waters with dangerous marine conditions including strong winds, rough short- period seas, heavy rain, and a chance for thunderstorms through Thursday. Vessels, especially small vessels, are strongly advised to remain in safe harbor for the duration of the storm, as these conditions can sink boats. South- facing harbors will also be especially vulnerable to the south swell and strong winds.
Details: South to southeast winds and seas to dangerous levels will affect the waters through Thursday night. High-end GALE conditions are expected, likely strongest north of Point Conception. These strong winds are expected to affect the nearshore waters, especially for unsheltered south-facing coastlines & areas north of Pt. Conception.
Large southerly short-period seas will occur through Thursday, leading to elevated, choppy seas at south-facing harbor entrances. There is a 15-30% chance of thunderstorms through early Thursday, which will bring a threat of erratic gusty winds, heavy downpours, cloud-to-water lightning and a small chance of waterspouts.
Ca, High Wind Warning remains in effect until 3 PM PST Thursday for zones 38-87-88-340>353-369-370-376>383-549-550. (See LAXNPWLOX). Flood Watch remains in effect through Friday afternoon for zones 38-87-88-340>358-362-366>383-548. (See LAXFFALOX). High Surf Advisory in effect until 11 AM PST Saturday for zones 340-346-349-350-354-362-366. (See LAXCFWLOX). Wind Advisory remains in effect until 3 PM PST Thursday for zones 354>358-362-366>368-371>375-548. (See LAXNPWLOX). PZ, Gale Warning in effect until 9 AM PST Friday for zones 645-670-673. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PST Friday for zones 650-655-676. (See LAXMWWLOX).
