24/114 PM.
High temperatures will remain above normal through Saturday with areas of low clouds and fog each morning. Substantial cooling is expected Sunday and Monday. Beach impacts from Polo are possible Monday and Tuesday in the form of high surf and possible beach erosion. A significant warming trend is expected Tuesday and Wednesday.
(Thu-Sun), 24/201 PM.
Marine layer clouds returned to southern California this morning as onshore flow increased by around 2mb. As a result, high temperatures dropped several degrees away from the immediate coast, and in some areas as much as 10-15 degrees below Wednesday's levels. Models indicate a very slight onshore trend again Friday with a similar marine layer pattern so Friday weather should look and feel a lot like Thursday. The cooler weather is expected to continue through the weekend with inland temperatures 5-10 degrees below normal. However, closer to the coast the influence of the much above normal SST's will keep coastal areas slightly above normal, generally in the mid to upper 70s.
(Mon-Thu), 24/227 PM.
Still plenty of uncertainty next week as Polo and Odalys swirl off central Mexico. In an odd twist the two storms are actually slowly moving towards each other and this will present some tricky track issues that may not be resolved until late this weekend. In the meantime, most of the ensemble solutions move Polo northwest, then inland over central Baja, while Odalys will soon shift to a slow move to the north. There is relatively high confidence that southern California will be impacted by southerly swells early next week. However, much less confidence in any rain chances, especially with the latest forecast tracks favoring a landfall for Polo somewhere in Baja Sur. Aside from that, some of the ensemble solutions have been indicating an increase in offshore flow Tuesday and Wednesday leading to 10-15 degrees of warming. However, still relatively low confidence in that pending where the tropical systems track.
25/0201z.
At 2234Z at KLAX, the marine layer was 1600 ft deep. The top of the inversion was at 3500 feet with a temperature of 25 C.
High confidence in VFR TAFs for KPRB, KPMD, and KWJF.
For all coastal TAFs: Arrival of cigs may be off by +/- 3 hours, lowest confidence for KBUR/KVNY. Cigs for KSBP may be shorter- lived. High confidence in low clouds at remaining sites, except moderate at KBUR/KVNY. Min cig heights may be off by +/- 300 feet.
KLAX, High confidence in TAF. Cigs may linger this afternoon and arrive as early as 00Z. No significant east wind component expected.
KBUR, Moderate confidence in TAF. There is a 15% percent chc of no low clouds tonight. 30% chance of OVC003-005 conds tonight.
24/143 PM.
Good confidence in northwest Small Craft Advisory (SCA) winds developing off and on across the outer waters and nearshore waters along the Central Coast from tonight through Monday of next week. There is a low chance for low end Gales late Friday. Winds are expected to remain below SCA levels elsewhere, except for around a 50% chance for SCA winds to move into the Santa Barbara Channel Sunday and Monday afternoon through evening.
These winds will help a short period and choppy NW swell build into the weekend, but seas are expected remain below SCA levels. Southerly swells from tropical systems Odalys (SW swell) and Polo (SE swell) will build into the waters as soon as late tonight, but Polo's SE swell is likely to not move into the region until late Sunday. The more significant swell from Polo will likely peak Monday and Tuesday, but confidence remains fairly low in the peak magnitude of the swell.
24/143 PM.
Tropical activity to our south will spin up multiple southerly swells and send them towards our coastline over the next week. Hurricane Odalys will send a smaller southwest swell to our waters as soon as tonight. Hurricane Polo will send a larger southeast swell to our coastline late Sunday through Tuesday. Polo's swell will produce elevated surf across exposed south facing coastlines. High tides near 7 feet will peak in the late morning hours Monday and Tuesday. The combination of elevated surf and high tides will present another coastal flooding issue across some south facing beaches.
This swell is likely to have a more southeast direction compared to the Labor Day weekend event and the areas of most concern are Long beach (Peninsula and Belmont shore), Avalon, Malibu, and possibly Santa Barbara Harbor.
The most likely outcome would result in shallow flooding over seawater over low lying walkways, parking lots, and roads as well as significant beach erosion. Very localized damage to structures is possible in the most vulnerable areas. However, there is a low chances for more widespread and significant flooding of seawater and structural damage across vulnerable areas.
There is a high chance for Coastal Flood Advisories to be issued as soon as tomorrow for the Monday-Tuesday timeframe.
Ca, NONE. PZ, Small Craft Advisory in effect from 3 PM to 9 PM PDT Friday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Saturday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect from midnight tonight to 9 AM PDT Saturday for zone 673. (See LAXMWWLOX).
