27/530 PM.
Beach impacts from Tropical Cyclones well south of the region are expected to peak Monday and Tuesday in the form of high surf, beach erosion, and possible coastal flooding. A significant warming trend is expected to begin Tuesday with increasing heat concerns through at least the following weekend.
(Sun-Wed), 27/800 PM.
***UPDATE***
The primary forecast concerns for the short term are the building surf along south facing beaches and potential for moderate coastal flooding. The tropical cyclones off the coast of Mexico are forecast to remain well south of Southern California, but the southerly swells from these storms will continue to affect the coastal waters through around midweek.
In addition to waves, some tropical moisture has also made its way to the area. High temperatures lowered 3 to 6 degrees on average compared to Saturday, and as much as 6 to 8 degrees in some areas. In spite of the cooler temperatures, the increased humidity caused muggy conditions closer to the coast.
Gusty onshore winds are affecting many interior areas this evening, with gusts generally 25 to 35 mph, but are expected to decrease later this evening. Winds will likely increase again Monday afternoon, from the northwest for the Central Coast and from the southwest to west for Ventura and LA Counties. These winds will result from an upper low moving southward across the state. This system has little moisture so the main effect will be increasing winds as described. Following this low, northerly gradients will increase some (-3.2 mb from LAX to Bakersfield) with windy conditions developing over SW Santa Barbara County and through the I-5 Corridor. By Tuesday morning winds will shift to the NNE, possibly reaching low-end Advisory levels.
These northerly winds will help to keep any low clouds near or off of the coast Tuesday and more importantly kick off a warming trend that will continue, especially away from the coast, through much of the coming week. High temperatures in the 80s and 90s will become common away from the immediate coast during this timeframe.
(Thu-Sun), 27/159 PM.
Above normal confidence in building heat into this weekend and it will likely remain quite hot for many areas into at least the middle part of next week. Moderate to high heat risk is possible with widespread highs in the upper 80s to low 100s in play. A fairly stagnant pattern with a moderate ridge and prevailing weak offshore flow (especially in the mornings) looks to be responsible for the impending heat wave. If current trends hold, this period of heat looks to be at least advisory worthy for many areas by the weekend.
National Hurricane Center (NHC) is tracking the newly formed Tropical Storm Rachel in the Eastern Pacific Ocean. The latest NHC track brings a Hurricane nearing our swell window by Friday. If this west to northwest track holds, it could enter our swell window by early next week. We will continue to monitor, however, any potential surf or coastal flood impacts would probably occur after October 4th.
28/0028z.
At 2354Z at KLAX, the marine layer was around 900 ft deep. The top of the inversion was at 1900 feet with a temperature of 24 Celsius.
High confidence in VFR TAFs for KBUR, KVNY, KWJF, and KPMD.
Moderate confidence in IFR conds at KSBP/KSMX with a 20% chance of brief LIFR conds at KSMX.
Moderate confidence in VFR TAFs for remaining sites. Chance of IFR to MVFR conds arriving after 10Z at KSBA (15%), KOXR (20%) and KCMA (20%). 30-40% chance of VFR conds at KSMO, KLAX , and KLGB.
Gusty onshore winds expected after 18Z Mon.
KLAX, Moderate confidence in the 00Z TAF. There is a 30% chance of MVFR CIGs 09Z-17Z Mon. If cigs form they may bounce between BKN and SCT frequently. High confidence in no significant east wind component. Gusty W-SW winds expected after 18Z Mon.
KBUR, High confidence in the 00Z TAF with VFR conds.
27/720 PM.
High confidence in Small Craft Advisory (SCA) winds and steep seas affecting the outer waters through late least Tuesday night. Local Gale Force gusts will be possible at times, especially Monday afternoon and evening across the outer waters south of Point Conception. There is a 25% chance for a Gale Warning to be issued for that time period. Nearshore along the Central coast will see SCA winds and steep seas each afternoon and evening through Tuesday.
For the nearshore waters south of Point Conception, SCA winds are expected across the entirety of the Santa Barbara Channel and portions of the inner waters adjacent to Los Angeles and Orange Counties on Monday, with moderate chances Tuesday.
Southerly swells from Hurricanes Odalys (SSW) and Polo (SSE) will continue to affect the region through Tuesday. These swells will create larger waves and surf nearshore, which could impact some harbor entrances.
Conditions are likely to improve to below SCA levels Wednesday into next weekend, except for occasional northwest SCA winds near Point Conception in the afternoon/evening hours.
27/803 PM.
Southerly swells from Tropical Storm Odalys and Hurricane Polo will affect the waters through the middle of this coming week, with Hurricane Polo likely sending the more impactful swell from the SSE (160-170 degrees) affecting our coastline Monday and Tuesday. This swell timing will line up with very high tides Monday and Tuesday in the late morning hours. Some south- facing shores are more vulnerable because of the lingering erosion effects from Hurricane Marie earlier this month.
Surf heights across Los Angeles and Ventura Counties are likely to peak around 4-7 feet Monday and Tuesday, while the Santa Barbara south coast should see surf in the 3-5 foot range. High tides build and peak Monday and Tuesday, likely reaching around 7 feet (MLLW) in the late morning hours - which is higher by almost a foot over astronomical tides due to ongoing effects of El Nino.
While this swell is slightly smaller than the swell from Marie, there is still significant concern of Coastal Flooding over vulnerable south-facing beaches. The areas of most concern include Avalon, Long Beach, Malibu, and to a lesser extent Santa Barbara. The reasonable worst-case scenario is for impacts similar to those from Hurricane Marie, but the most likely outcome is for impacts to be a step less. The one exception being Avalon on Catalina Island, as the swells from Hurricane Polo will be more from a southeasterly direction than with Marie, which they are more exposed to. The same goes for Santa Barbara Harbor where the risk is less but still present.
South-facing beaches should plan for shallow flooding of seawater over low lying beach walkways, parking lots, and roads as well as potential for significant beach erosion. Very localized damage to structures is possible in the most vulnerable areas. Minor tidal overflow may affect west facing beaches due to very high tides.
Beach Hazards Statements (BHS) are in effect for LA and Ventura coasts through early Monday morning, and for the Santa Barbara south coast into Wednesday. Then a Coastal Flood Advisory and High Surf Advisory are in effect for LA and Ventura Monday and Tuesday. A BHS may need to be issued for the LA and Ventura coasts for Tuesday afternoon through Wednesday (lining up with Santa Barbara) due to the very high tides.
Ca, Beach Hazards Statement in effect until 5 AM PDT Monday for zones 87-354-362-366. (See LAXCFWLOX). Coastal Flood Advisory in effect from 5 AM Monday to 5 PM PDT Tuesday for zones 87-354-362-366. (See LAXCFWLOX). High Surf Advisory in effect from 5 AM Monday to 5 PM PDT Tuesday for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Wednesday afternoon for zones 349-350. (See LAXCFWLOX). Wind Advisory in effect from 6 PM Monday to 6 AM PDT Tuesday for zones 349>353-376>378. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Monday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from noon to 11 PM PDT Monday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from noon Monday to midnight PDT Monday night for zones 650-655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX).
