11/111 PM.
A cooling trend will affect the region through the weekend with max temps dropping to below normal almost everywhere by Sunday. The sticky tropical air will finally exit the region by tomorrow. Night through morning marine layer clouds will likely continue across most coastal areas.
(tdy-Mon), 11/133 PM.
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.
11/1718z.
At 1622Z at KLAX, the marine layer was 1700 ft deep. The top of the inversion was at 2600 ft with a temperature of 25 C.
High confidence in VFR TAFs for desert airfields (KPMD & KWJF).
Moderate confidence in VFR conditions for KPRB (10% chc of brief LIFR CIGs 12/12Z-15Z), KVNY (15% chc of LIFR/IFR CIGs 10Z-15Z).
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 TAF. Arrival and clearing of IFR to MVFR Cigs (008-012) may be off +/- 2 hours. No significant east wind component expected.
KBUR, Moderate confidence in TAF. 15% chc of LIFR/IFR CIGs 12/10Z-15Z. No wind issues expected.
11/1244 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. 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. Small Craft Advisory (SCA) conditions are expected to reach into the nearshore waters along the Central Coast and the Santa Barbara Channel at times (especially during afternoon/eve hours) through early next week.
Ca, Heat Advisory in effect until 6 PM PDT this evening for zones 349-350-354-355-362-366>368. (See LAXNPWLOX). Wind Advisory in effect from 6 PM this evening to 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).
