03/831 AM.
Warmer temperatures with locally gusty Santa Ana winds will return today and continue through Thursday. The winds and temperatures will peak Wednesday. Cooler temperatures are expected Friday and over the weekend but highs will still be at least 4-8 degrees above normal. There will be a chance of rain by next Tuesday.
(tdy-Thu), 03/845 AM.
***UPDATE***
After a brief respite in the unseasonably warm temperatures the last couple days, another warming trend is expected to begin today and last through Thursday. Already seeing signs of the warm up this morning with most foothill and lower mountain locations in the 70s at 9am, which would be 10-20 degrees warmer than yesterday at this time. Will see that warm up expand to sea level over the next couple hours as the warm air breaks through the 500 foot marine inversion. Offshore breezes have already begun in some areas this morning, strongest in Browns Canyon in the northern San Fernando Valley with winds around 45 mph. Overall not expecting advisory level winds today but more likely Wednesday when offshore flow is at its peak.
***From Previous Discussion***
No change to the thinking that Wednesday will be the warmest and the windiest. At the upper levels there will be a 585 dam upper high centered over Sierra and Nevada counties with 582 dam hgts. At the sfc the offshore flow will peak as the Great Basin sfc high increases. Look for around 5 mb of offshore flow from both the N and E which when coupled with some easterly upper level winds will result in low end advisory gusts through the usual Santa Clarita to Point Mugu Santa Ana Wind Corridor. Longer days, a warm atmosphere and offshore flow will all combine to bring 4 to 8 degrees of warming to the csts and vlys (1 to 3 for the interior). This warming will bring 80s to almost all of the csts and vlys. A few records are possible, particularly Burbank (record 86), LAX (record 84), and Long Beach (record 87).
Offshore flow weakens on Thursday esp the N/S gradient which collapses from 4 or 5 mb Wed morning to around 1 mb Thursday morning. There will still be offshore winds but they will be more easterly than northeasterly. The gusts will be under advisory levels as well. At the upper levels a weak trof will sweep in from the SW and hgts will drop to 572 dam. Max temps will fall a few degrees but will still remain many degrees above normal.
(Fri-Mon), 03/309 AM.
A weak trof or cut off low with fairly high hgts (~570 dam) will wobble and drift over the area. While the chc of a shower is not zero it is less than 10 percent. The main cloud mass assoc with the system will move over the area on Friday making it a mostly cloudy day. Falling hgts and weak cyclonic lift will bring marine layer low clouds to csts and lower vlys both days, but skies will clear to partly cloudy on Saturday. Max temps will collapse by 10 to 15 degrees across csts/vlys on Friday with the interior temps falling by 4 to 8 degrees. Aside from a little more cooling across the interior on Saturday max temps will not change much form Friday's values. Max temps both days will mostly be in the lower to mid 70s across the csts/vlys which is still 3 to 6 degrees over normal.
On Sunday a ridge will nose in from the west and hgts will bump up to about 580 dam. There will be weak offshore flow both from the E and N but not enough to create much of any winds. Max temps will warm under sunny skies and will end up in the 70s across csts/vlys.
Moist WSW flow moves in during the day on Monday. It will bring a grip of clouds at first with a slight chc of rain for the Central Coast in the afternoon. A sharper trof is forecast to arrive Tuesday and is currently forecast to spread a 40 to 50 percent chc of rain across the entire forecast area. If this system does come to fruition it will likely produce between a quarter and a half inch of rain.
Both the AI version of the GFS and EC are indicating a more potent system sometime in the 15th to 17th time period.
03/1955z.
Around 18Z at KLAX, there was a 200 ft marine layer. The inversion top was 1600 ft and a temp of 22 degrees C.
High confidence in VFR TAFs with just a 10 percent chance of LIFR conds or lower for KLAX KLGB and KSMO 04Z to 10Z.
Moderate confidence in winds. The strongest winds of for the Santa Ana Wind Corridor including KVNY KCMA and KOXR will likely fall just after 18Z Wednesday.
KLAX, High confidence in TAF. There is a 10 percent chance of LIFR conds or lower between 04Z and 10Z. Any east wind component should remain under 6 kts.
KBUR, High confidence in TAF.
03/914 AM.
Offshore northeast winds will develop each morning near Morro Bay, generally below SCA levels. There is a 40-50% chance for localized east wind gusts near SCA levels around the Channel Islands Wednesday morning into early afternoon. However, less confidence in winds Wednesday evening into Thursday afternoon as there is a 30% chance of SCA level SE winds north of the Channel Islands. Otherwise, another round of at least SCA level winds and seas across the outer waters will be likely Friday into Saturday, and SCA winds may linger into the following week.
For the Inner Waters south of Point Conception, moderate confidence in current forecast. Seas of 4-8 feet will continue to decrease through the day. Then, tonight through Wednesday and potentially into Thursday morning, there is a 50-60% percent chance of east to northeast SCA level winds from Ventura south to Santa Monica and out past Anacapa Island, as well as potentially through the San Pedro Channel (less confidence in this area though). A Small Craft Advisory has been issued for Santa Ana NE winds late tonight into Wednesday afternoon, however, it may need to be extended through Thursday morning. Additionally, Gale Force wind gusts will be likely nearshore below mountain canyons and passes, with a 30-40% chance of extending north to Ventura and out to Anacapa Island late tonight through Wednesday morning. Otherwise, conds will remain below advisory levels until northwest winds potentially increase to SCA levels across the waters early next week, especially Tuesday.
Ca, High Surf Advisory in effect until 4 PM PST this afternoon for zones 340-346-354. (See LAXCFWLOX). Beach Hazards Statement in effect until 4 PM PST this afternoon for zones 362-366. (See LAXCFWLOX). PZ, Small Craft Advisory in effect from midnight tonight to 3 PM PST Wednesday for zones 650-655. (See LAXMWWLOX).
