25/211 AM.
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 Tropical Cyclone 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.
(tdy-Sun), 25/337 AM.
Marine layer clouds this morning overspread the Central Coast and are starting to spread into the inland coasts south of Point Conception. Ecpecting these clouds to burn off by mid to late morning. Daily highs are expected to be a few degrees above normal through Saturday, then lowering Sunday and Monday before additional warming starts again next Tuesday. For the next two days, highs will be around 4 to 6 degrees above normal, and 8 to 10 degrees above normal in the warmest areas. Sunday and Monday most areas away from the coast will be a few degrees below normal. However, closer to the coast the high sea surface temperatures will keep coastal sections slightly above normal, in the 70s to near 80.
Winds are currently fairly weak across the area, except for gusty onshore winds through some passes and canyons of LA County, strongest into the Antelope Valley. Onshore gradients are forecast to gradually increase through the next couple of days, so expect these onshore winds (currently gusting to 35 mph at Lake Palmdale) to increase some during this time. In addition, the Santa Barbara to Santa Maria gradient will strengthen with potential for some gusty Sundowner winds over SW Santa Barbara County Saturday night or more likely Sunday night.
(Mon-Thu), 25/210 AM.
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. Guidance seemed undecided in how much PWAT values will increase Sunday into Monday, so will have to wait to see if PWATs or other precip related parameters come into better alignment over the next few days. 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.
25/1212z.
Around 12Z at KLAX, the marine layer was 1000 ft deep. The top of the inversion was at 2600 feet with a temperature of 25 C.
High confidence in VFR TAFs for KPRB, KPMD, and KWJF.
Moderate confidence in remainder of TAFs. Timing of flight cat changess may be off by +/- 3 hours. There is a 20% chance of IFR conds at KBUR and KVNY through 17Z Fri. There is a 30% chance of conds at KOXR, KCMA, and KSBA after 08Z Fri, and a 30% Chance of VFR conds Friday night.
KLAX, High confidence in TAF. Timing of flight cat chages may be off by +/- 3 hours. No significant east wind component expected.
KBUR, Moderate confidence in TAF. There is a 20% percent chc of OVC005 conds through 17Z Fri.
25/235 AM.
Good confidence in northwest Small Craft Advisory (SCA) level winds developing off and on across the outer waters and nearshore waters along the Central Coast through Monday of next week. There is a low chance for low end Gales late tonight. 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 starting today, 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. These southerly swells could bring hazardous, larger breaking waves near the shore and in and around harbor entrances.
25/156 AM.
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 today. 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 of 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 this afternoon to 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Saturday for zones 670-673. (See LAXMWWLOX).
