07/952 PM.
A warming trend will begin today as high pressure starts to nudge into the area from the west. Desert areas will reach triple digit temperatures by mid week. Night and morning low clouds and fog are still expected across most coast and some coastal valleys through the week. Skies will clear by afternoon, except some beaches will remain cloudy most of the day. Gusty Sundowners are expected in western Santa Barbara County Monday and Tuesday.
(tdy-Thu), 08/944 AM.
Today will be the last day of below normal temperatures before transitioning to a warming pattern through mid-week. The marine layer is sitting at 2300 feet south of Point Conception with low clouds as far inland as Ojai and Pasadena. Along the Central Coast the marine layer is around 1000 feet and is already clearing. For southern areas, low clouds will take some more time to clear, keeping beaches cloudy into the early afternoon. Temperatures will stay cool today, similar to yesterday.
***From previous discussion***
The upper level trough across the PNW responsible for the relatively cooler weather will begin to break down ahead of an upper level ridge gradually building in through mid-week. Widespread warming will initiate today and continue through Wednesday. Most notable warming will occur across coastal valleys and interior areas, as coasts will still feel marine influences due to moderate onshore flow. There is some uncertainty, however, regarding how much temperatures will increase near the coasts on Wednesday. Onshore LAX-DAG pressure gradients are projected to drop rapidly to near neutral by Wednesday morning, which would limit most if not all marine influences. This would result in a fairly dramatic increase in temperatures at locations typically moderated by marine air during this time of year. Warmest coastal valleys can expect temperatures to reach the mid 90s by Wednesday, but there remains a low (10 percent) chance for some of the warmest spots to reach 100 degrees. There is a 20 percent chance for Heat Advisories on Wednesday across some of the warmer valleys, namely the southern Salinas, Santa Clarita, and western San Fernando Valleys.
Wind advisories have been issued for northwest winds across the Santa Barbara Southwest Coast and through the I-5 Corridor for Monday night into early Tuesday morning. Slightly stronger northwest flow Tuesday may prompt more wind advisories, with best chances along the immediate Central Coasts, southwest Santa Barbara County (west of HWY 154), and the interior mountains (especially I-5 Corridor).
(Fri-Mon), 08/127 AM.
Consistent high pressure and generally onshore flow will keep very similar temperatures from late this week through the weekend. Temperatures each day will generally be around 5 to 10 degrees above normal. There is a small chance of temperatures slightly warmer than forecast at the coast on Thursday, due to briefly weaker onshore flow. Morning marine layer clouds will continue to be a fixture of the weather pattern, though clouds may be more minimal on Thursday with weaker onshore flow. Higher 500 mb heights will reduce the inland extend of clouds, keeping them focused over the beaches and coastal plains.
08/1824z.
At 1640Z at KLAX, the marine layer was 2700 feet deep. The top of the inversion was 4400 feet with a maximum temperature of 17 C.
High confidence in VFR TAFs for KPRB, KPMD, and KWJF.
Moderate confidence in remaining TAFs. Timing may be off +/- 2 hours, there is a 30-50% chance of IFR cigs tonight.
KLAX, Moderate confidence in TAF. Timing of flight category changes could be +/- 2 hours of current forecast, there is a 25% chance of IFR cigs tonight. Any east wind component is expect to be less than 6 kt.
KBUR, Moderate confidence in TAF. Timing of flight cat changes may be off +/- 3 hours, with a 20% chance of IFR cigs tonight.
08/1203 AM.
For the Outer Waters, moderate to high confidence in current forecast. High confidence in a combination of Small Craft Advisory (SCA) level winds and seas through Thursday. Today and Tuesday, there is a 30-50% chance of Gale force winds over the southern two outer zones (PZZ-673 and PZZ-676) during the late afternoon and night period, with the best chances on Monday. SCA winds are likely to persist through Wednesday night, then weakening Thursday through Friday.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Through Wednesday, SCA level wind are expected, mainly in the afternoon and evening hours, with seas near or above SCA levels. On Thursday and Friday, winds and seas are expected to remain below SCA levels.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For a majority of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Friday. The only exception will be the western half of the Santa Barbara Channel, where there is a 40-60% chance of SCA level winds today and Tuesday, mainly in the late afternoon and evening hours.
08/1204 AM.
A long period south swell will move through the waters Tuesday through Thursday, with swell height building to 3 feet nearshore. Periods will initially be 19 seconds, decreasing to 15 seconds by Thursday. Surf is forecast to build to 3 to 6 feet with local sets to 7 feet along south facing shores of Los Angeles and Ventura Counties. There is a chance of more widespread surf of 4 to 7 feet with larger sets, in which case a high surf advisory will be needed.
Hazardous surfing and swimming conditions are expected due to the building surf, along with strong rip currents.
Ca, Beach Hazards Statement in effect from Tuesday morning through Thursday evening for zones 87-354-362-366. (See LAXCFWLOX). Wind Advisory in effect from 5 PM this afternoon to midnight PDT tonight for zones 349-351. (See LAXNPWLOX). Wind Advisory in effect from 9 PM this evening to 10 AM PDT Tuesday for zone 378. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Tuesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Tuesday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 8 PM PDT this evening for zones 673-676. (See LAXMWWLOX). Gale Warning in effect from 8 PM this evening to 3 AM PDT Tuesday for zones 673-676. (See LAXMWWLOX).
