11/707 PM.
A cooling trend will affect the region through the weekend with high temperatures dropping to near or below normal almost everywhere by Sunday. The sticky tropical air will finally exit the region by Saturday. Night through morning marine layer clouds will likely continue across most coastal areas.
(Fri-Mon), 11/840 PM.
***UPDATE***
Another sunny day occurred today, with high temperatures in the 70s and 80s at the coast, increasing into the 90s to barely 100 further away from the coast. High temps were 5 to 10 degrees below yesterday for most of the region, except the Central Coast, where temperatures were 10 to 20 degrees cooler. Despite being a bit cooler, temps were still 5 to 15 degrees above normal for this time of year. Overnight lows will be cooler as well, with most areas in the 60s to very low 70s, especially as the tropical moisture continues to decrease across the region. Marine layer clouds will make a return tonight and expand across the Central Coast, as well as across the Los Angeles County Coast and possibly into the inland coast. However, the marine layer clouds over the ocean along the Central Coast are starting to clear out, making it questionable if the clouds will stick around long. Additionally, a wind advisory is in effect until 3am for SW Santa Barbara County for N to NW Sundowner winds.
As for tomorrow, another sunny day is on tap once the marine layer clouds burn off. High temperatures will continue to decrease across the region by about 5 to 10 degrees again, as well as the tropical moisture decreasing even more. Another round of Sundowner advisory level winds will occur tomorrow evening as well as night through morning marine layer clouds across the coasts.
Allowed the heat advisories to expire on time, and no big updates were needed for the evening forecast update.
***From Previous Discussion***
Heat advisories will continue through this evening for coastal areas from Santa Barbara south through Los Angeles due to moderate risk of heat illness with max temps forecast to be around 10 degrees above seasonal normals along with lingering humidity. Some inland areas will be around 5 degrees above normal, but we will hold off on any additional heat advisories.
Fairly quiet next few days once the heat advisories expire. The ridge responsible for this past extreme heat event will continue to flatten out through today and further cooling is expected through at least Sunday, with areas south of Point Concpetion cooling into Tuesday. In general max temps will be below seasonal normals Saturday into at least early next week. Maybe more noticeable will be the decreasing humidity ad PWATs drop from around 1.5" to 0.75" by tomorrow night.
The one exception to the quiet weather is the potential for advisory level Sundowner winds tonight through the weekend, likely peaking Saturday or Sunday. A wind advisory has been issued for tonight across the Santa Barbara southwest coast.
Expecting a more robust marine layer tonight with stratus currently hugging the Central Coast and a patch spinning off the LA County Coast. Then a more consistent marine layer will likely be common, except for southern Santa Barbara County and possibly Ventura County since the Sundowners may keep clouds from surging into the Santa Barbara Channel.
(Tue-Fri), 11/110 PM.
Not much change through Wednesday, with zonal flow continuing at the upper levels. Temperatures will remain below seasonal normals. Weak to moderate onshore flow will continue with light northerly offshore flow each night through morning. There will likely be some morning low clouds each day with the greatest coverage across the Central Coast. Skies, otherwise, will be mostly clear.
A good degree of mdl confusion creeps into the forecast later Wednesday into Thursday as the mdls struggle with the handling of some energy coming out of British Columbia. The sfc pattern is also in question as there is wide assortment of possible values ranging from 1mb onshore to 6.5 mb onshore. While the actual outcome regarding how much warmer it will be and how quickly things warm up is still uncertain, ensembles suggest a slight warming trend Thursday and Friday. So confidence in at least some warming is growing, with the details remaining in question. A majority of the European ensemble members also increase PWATs to over 1.0" as early as Thursday, so there is also potential for increased mugginess once again. The good news is most members are keeping PWATs below 1.5", much lower than the peak of the extreme heat and humidity this past week.
No significant wind issues are expected, although there will be the usual gusty southwesterly winds each afternoon across the mountains and deserts and the typical near advisory level evening gusts across the SW corner of SBA county.
12/0207z.
At 0053Z at KLAX, the marine layer was 1000 ft deep. The top of the inversion was at 2300 ft with a temperature of 27 C.
High confidence in VFR TAFs for desert airfields (KPMD & KWJF).
Moderate to high confidence in VFR conditions for KPRB with a 10-20% chance of brief LIFR CIGs 12/12Z-15Z).
Low confidence in TAFs for KBUR and KVNY with a 20% chc of low clouds 10Z-15Z. CIGs most likely IFR if they occur.
For remaining TAFs, low to moderate confidence. Timing of CIG/VSBY restrictions may be off +/- 3 hours & flight minimums by one category.
KLAX, Moderate confidence in the 00Z TAF. Arrival and clearing of IFR to MVFR Cigs may be off +/- 2 hours. 20% chance of no low CIGs. No significant east wind component expected.
KBUR, Low confidence in the 00Z TAF. 20% of CIGs between 12Z-16Z, most likely IFR but MVFR possible.
11/809 PM.
Conditions are expected to become increasingly hazardous across the outer waters into the weekend. A Gale Watch (50-60% chc) has been issued for PZZ676/673 Saturday evening into Monday morning. Models indicate that the stronger winds may occur later in the evening and overnight, with gales then possible through Monday mid-morning.
The coastal Jet may develop across PZZ670 Saturday evening causing winds to increase there as well, but confidence in winds reaching Gale force is low at this time. Otherwise, widespread SCA winds are expected across the outer waters through early next week. Even as the likely gales subside Monday late morning, SCA winds are likely across the outer waters through Tuesday morning.
Small Craft Advisory (SCA) conditions are expected nearshore along the Central Coast Saturday afternoon through Monday night. In the Santa Barbara Channel, SCA winds are likely each afternoon to evening in the western Channel through Saturday. Sunday afternoon through Monday evening SCA winds are expected to persist through the period.
Hazardous, steep seas are expected during this time, building to over 10 feet at short periods over the outer waters and possibly to 8 feet or above along the Central Coast. Peak waves are expected Sunday into Monday. Dangerous choppy seas are also expected in the SB Channel, 5-7 feet at short periods.
Ca, Wind Advisory in effect until 3 AM PDT Saturday for zones 349-351. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Saturday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Monday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 6 PM PDT Saturday for zones 673-676. (See LAXMWWLOX). Gale Watch in effect from Saturday evening through Monday morning for zones 673-676. (See LAXMWWLOX).
