25/1249 AM.
Two more impulses will move through the area today and Friday and will bring periods of showers and a slight chance of thunderstorms. The potential for flooding will be high during this period. Showers are expected to pater off by late Friday evening with dry and warmer weather returning for the rest of the weekend through the middle of next week.
(tdy-Sun), 25/221 PM.
Little change to the current forecast.
Two more impulses are slated to run through the area today and tonight/Friday morning. The first impulse will enter the Central Coast around dawn this morning and will exit LA county late this afternoon. Impulse number 2 will enter the Central Coast this evening and exit LA county around noon on Friday. The first impulse will bring about an inch to an inch and half of rain to the csts/vlys and 2 to 4 inches to the mtns of SLO/SBA/VTA counties. LA county will likely recieve only half of these values as the impulse is fcst to weaken as it moves through VTA county. The opposite in rainfall distribution will likely occur for impulse #2 where less than an inch will fall over most of SLO and SBA counties and only a little more over VTA county. LA county , however, will see a good southerly moist unstable flow into the county after midnight Friday and will likely see inch to an inch and half of rain to the csts/vlys and 1.5 to 3 locally 4 inches to the mtns.
The flooding threat will be exacerbated today and Friday due to the super saturation of all of the area. Any rainfall that occurs will immediately turn to run off.
Snow levels will be around 6000 ft due the cooler air assoc with these systems and there will be a few inches of accumulating snow above this level. Snow levels fall to near 5000 ft Friday evening but by then most of the precip will have ended.
Most max temps both days across the csts and vlys will end up in the upper 50s and lower 60s which is pretty typical for December storms.
Unstable air and weak PVA will keep a slight chc of showers going on Saturday (mainly in the morning). Additional rainfall will not amount to more than a quarter inch and likely under a tenth. It will still be a mostly cloudy day with lower than normal hgts but max temps should rise a few degrees into the lower to mid 60s.
(Mon-Thu), 25/221 PM.
Mdls are in much better (but not perfect) agreement for the Sunday through Tuesday period. Both the EC and GFS as well as most of their ensemble members now show some sort of upper ridge nosing in from the west and decent (4 to 6 mb) offshore flow developing from both the north and east. Low end advisories are possible each day. Skies will be mostly clear and the sunshine and offshore flow will team up 2 to 4 locally 5 degrees or warming each day. By Tuesday max temps across the csts and vlys will be in the upper 60s to the mid 70s (mostly 3 to 6 degrees over normal)
Not much agreement on Wednesday but about 20 percent of the ensembles show some rain. A better chc of will develop next Thursday. Right now it looks like that any rain that does come from this system will be on the light side.
25/2223z.
New aviation discussion coming soon.
25/217 PM.
A winter storm will continue through Friday and will bring hazardous marine conditions including gusty winds, rough short- period seas, heavy rain, and a chance for thunderstorms.
Gusty south winds to Small Craft Advisory (SCA) levels will affect the waters through Friday morning. The outer waters will also see SCA level seas Fri through Sat.
There is a 10-20% chance of thunderstorms through Friday, 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 this afternoon for zones 38-340>353-376>383. (See LAXNPWLOX). Flood Watch now 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 this afternoon for zones 354>358-362-366>368-371>375-548. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 PM PST Saturday for zones 645-670-673-676. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PST Friday for zones 650-655. (See LAXMWWLOX).
