26/1125 PM.
It will be dry this weekend will with warmer and breezy conditions developing Sunday. A strong Santa Ana wind event is expected Monday with a slightly weaker on on Tuesday Tuesday. Clouds will increase and a slight chance of rain will develop Wednesday. The new year will likely start off with quite a bit of rain.
(tdy-Mon), 27/826 AM.
***UPDATE***
Latest satellite and surface observations indicate clear skies across the area, except for some stratus across interior San Luis Obispo county and southeastern LA county. Northerly winds, gusting 25-35 MPH, are observed across the Santa Ynez Range in Santa Barbara county.
Forecast-wise for the immediate short term, no significant issues are expected. Current stratus will dissipate by late morning with sunny skies for all areas this afternoon. Northerly winds will continue through this evening, but any advisory-level winds are expected to remain localized. High temperatures will remain on the chilly side as cold post-storm airmass is still in place over the area.
Overall, current forecast has good handle on the immediate short term. So, no significant updates are expected. For the afternoon forecast suite, attention will turn to moderate to strong Santa Ana winds Monday/Tuesday.
***From Previous Discussion***
Dry conditions have finally arrived. High pressure is nosing in form the west as ydy's trof moves to the east. Hgts will be a below normal 562 dam. Despite the sunny skies max temps will actually end up a degree cooler than ydy due to all of the cool air advection behind the front.
A Santa Ana wind event will start on Sunday as the upper high pushes far enough inland to turn the upper level winds into an easterly direction. At the sfc a sfc high will migrate into the Great Basin and 4 to 5 mb offshore flow will develop from both the N and E. A low end advisory event is possible but more likely the gusts will come in just under advisory criteria. Skies will be mostly sunny and max temps will jump 3 to 6 degrees, but will remain blo normal.
A strong Santa Ana event will occur on Monday as the offshore push from the east increases to 8 mb and the offshore push from north will peak around 5 mb. There will be 40 to 50 kts of NE flow aloft at 850 mb to add extra oomph to the event. Warning level gusts look likely for the mtns(including the Santa Monicas) with high end advisory gusts 8 to 12 miles either side of a line extending from Santa Clarita to Leo Carrillo. This will be a worrisome wind event since the recent rainfall will make trees more susceptible to toppling. Max temps will rise 2 to 4 degree and end up in the mid and upper 60s.
(Tue-Fri), 27/236 AM.
The Santa Ana event will continue on Tuesday. The gradients are a little weaker and as is the upper support. Still it looks robust enough to generate some advisory level gusts in the morning. Look for sunny skies through the day. 2 to 4 local 5 degrees of warming will result from the offshore flow and copious sunshine. Max temps will rise to the upper 60s and lower 70s which will bring most max temps to above normal.
The EC and GFS as well as most of their ensemble members agree in principle that an upper low will develop well to the SW of KLAX early Monday and will steadily move to the northeast. By Wednesday it may be close enough to bring rain to the southern portion of the forecast area. It is an interesting scenario because there will still be some decent Santa Ana winds occuring which will dry the lower atmosphere. So only a slight chc of rain in the morning but a 30 to 40 percent chc in the afternoon. If it does rain totals through 10 pm will be on the light side: under a quarter inch. Even if the rain holds off there will be increasing clouds through the day. Max temps will fall with the increase in clouds and decrease in offshore flow.
The upper low will further approach the area on Thursday and Friday. Rain now looks likely (50 to 60 percent chc from midnight to dawn and 60 to 70 percent both in the morning and afternoon). Rain also looks likely on the 2nd. This storm will not nearly be as strong as the current one. Rainfall totals from 10pm New Years Eve to 10pm new years day will likely be between .75 and 1.50 inches with local 2 inch amounts. It will likely not rain as much Friday: a quarter to three quarters of an inch. Max temps both days will be in the lower to mid 60s with morning lows in the lower to mid 50s (upper 40s and lower 50s for the Central Coast).
27/1146z.
Around 12Z at KLAX, there was no marine layer nor an inversion. There was a 7000+ ft moist layer.
High confidence in all TAFs. There may be periods of IFR-MVFR vis overnight at any TAF location due to wet runways, as well as MVFR cigs that scatter and reform frequently at KPRB, KSMX, and KSBP through 16Z.
KLAX, High confidence in TAF. Wind may remain VRB03kt through 18-19Z Sat, and there is a 10% chance of 3-5 SM BR through 15Z. Good confidence in any east wind component less than 6 kt.
KBUR, High confidence in TAF. There is a 10% chance of 3-5 SM BR through 15Z.
27/204 AM.
Small Craft Advisory (SCA) west to northwest winds will affect mainly the outer waters through tonight. Seas will remain large and steep, gradually diminishing through this weekend and remaining below SCA levels through the week.
Sunday night through at least Tuesday morning (and possibly again Tuesday night into Wednesday), offshore winds will make a return to the inner waters. Strong SCA level NE winds, with Gale Force gusts possible, will be focused from Ventura to Santa Monica with the strongest winds from Oxnard to Point Dume. These winds may extend all the way to the outer waters north of San Nicolas Island, with the highest chances on Monday morning.
Ca, High Surf Advisory in effect until 11 AM PST this morning for zones 340-346-349-350-354-362-366. (See LAXCFWLOX). PZ, Small Craft Advisory in effect until 3 PM PST this afternoon for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PST Sunday for zones 670-673-676. (See LAXMWWLOX).
