10/231 AM.
Extreme heat and humidity will continue today with a high risk for heat illness. Cooling is on tap for Friday and especially Saturday with max temps returning to normal. Marine layer clouds will likely return .
(tdy-Sat), 10/814 AM.
***UPDATE***
The forecast remains on track and we have once again begun the day with very warm temperatures, in fact, most of the populated ares of LA and Ventura counties saw minimum temps reach the 70s, with some isolated areas remaining in the 80s, The Central Coast saw lows in the mi to high 60s. The still elevated dewpoint temps certainly played a role in keeping it hot and humid overnight.
The forecast remains on track with a "less hot" day compared to yesterday, but it will still be very hot and muggy today as our Extreme Heat Warnings continue through tonight. The only exception to this "cooling" trend will be in the mountains and interior, where temps may be a couple degrees warmer than yesterday.
The other aspect of the forecast that requires attention this morning is the addition of a slight chance of thunderstorms over the interior mountains this afternoon, with best chance over the Eastern San Gabriels and northern Ventura County mountains. Chances are lower than yesterday and there isn't much of any lifting mechanism aside from the hot air and terrain, so really expecting this potential to be focused just in the mountains. With any thunderstorm that form, the air is juicy enough to produce some brief, heavy downpours along with gusty winds and lightning.
***From Previous Discussion***
Wednesday was the peak of the heat and there will be cooler conditions today but not enough cooling to prevent heat related danger and Heat Warnings will continue through this evening.
The upper high over AZ will weaken through the day and by afternoon hgts will fall to 592 dam. More importantly (at least for the csts/vlys) The offshore flow in the morning will be much weaker and will quickly turn onshore by late morning and then increase through the afternoon. These onshore trends will bring an earlier arrival of the sea breeze and also a strong one. PWATs unfortunately will remain well above normal.
The combination of falling hgts and better onshore flow will bring 4 to 8 locally 10 degrees of cooling to the csts and vlys. The mtns and interior may see a degree or two of warming. Max temps, however, will remain 10 to 15 degrees over normal and this along with overnight lows only in the 70s and lower 80s for many locations will keep the very high heat risk going for one more day.
On Friday the ridge flattens out in response to an upper low moving into the PACNW and hgts will fall another 2 dam to 590 dam. Onshore flow will increase by another 1 to 2 mb. This combination will lead to another 4 to 8 locally 10 degrees of cooling across the board including the interior. This additional cooling will lower most max temps to 3 to 6 degrees above normal. The other good news for Friday will be a noticeable drop in humidities as PWs fall to 1.4 inches over srn LA county and a very pleasant .70 over SLO county. This cooling and drying should eliminate the need for any extension of the heat products.
The continued onshore flow should bring some low clouds back to the area Saturday morning esp across the Central Coast. Another 3 to 6 degrees of cooling will bring max temps down to normal values.
Lastly advisory-level Sundowners are likely every evening starting tonight. The strongest gusts will be west of Isla Vista.
(Sun-Wed), 10/231 AM.
A refreshing return to benign srn CA weather is set for the xtnd period. Fairly flat and zonal flow will stream over the top of SoCal through the period and hgts will mostly range from 586 dam to 588 dam. At the sfc there will be weak to moderate onshore flow in the E/W direction. The N/S gradinets will feature weak offshore flow in the mornings and weak onshore flow in the afternoons.
There will be some morning low clouds each day with the greatest coverage across the Central Coast. Skies, otherwise, will be mostly clear.
Most areas will cool through Tuesday and Tuesday's highs will be in the 70s across the csts and only lower to mid 80s across the vlys. These temps are mostly 5 to 10 degrees blo normal.
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.
10/0931z.
At 0833Z at KLAX, there was no marine layer. There was a sfc based inversion with a top at 1200 feet and 34 degrees C.
High confidence in VFR conditions at all sites through at least Thursday with typical winds.
KLAX, High confidence in CAVU TAF. Any east component will be AOB 6 kts.
KBUR, High confidence in CAVU TAF.
10/756 AM.
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 but confidence is too low if winds will reach Gale strength at this time. 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).
Ca, Extreme Heat Warning in effect until 8 PM PDT this evening for zones 38-87-88-340>358-362-366>375-548. (See LAXNPWLOX). Beach Hazards Statement in effect through this evening for zones 87-349-350-354-362-366. (See LAXCFWLOX). PZ, Small Craft Advisory in effect from 3 PM this afternoon to 11 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Friday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 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).
