20/306 AM.
Night through morning marine layer clouds will be confined to the coastal areas, mostly north of Pt Conception, through much of this week. Warm conditions are expected away from the immediate coast slight cooling is forecast Friday through the weekend.
(tdy-Sat), 20/306 AM.
Another hot day on tap today. Low clouds will be mostly confined to the Central Coast with only patchy coastal low clouds occuring south of Pt Conception. 595 dam hgts, weak onshore flow and a limited marine layer will allow max temps to reach 95 to 105 degrees in the vlys, lower mtn elevations and the far interior where heat advisories are in effect. Less hazardous but still above normal temps will occur across the rest of the area.
A little change in fcst for tonight. A weak disturbance will rotate over LA county later in the evening and overnight. All hi rez convection allowing mdls show this disturbance generating some convection as it passes overhead. Have added a 15 to 20 percent chc of showers and TSTMs to the LA county overnight forecast.
Onshore flow will continue to bring low clouds to the Central Coast. Less confidence on the extent of the morning low clouds south of Pt Conception as the overnight disturbance may prevent their formation. Better onshore flow, slightly lower hgts and increased mid and high level clouds from the SE monsoon flow aloft will all conspire to lower max temps a few degrees. Humidities may rise a little so it might not feel much better. None of the convection allowing mdls show any development in the afternoon, but given the flow pattern and increasing mid level moisture the current 10-15 percent chc of convection over the eastern San Gabriel's and nrn VTA county mtns seems reasonable.
Clearer skies Friday night and increased onshore flow at the sfc should help more low clouds form south of Pt Conception Saturday morning. There will be decreased moisture at the mid levels so the chc of afternoon convection over the mtns is lower (5 to 10 percent chc). The sunnier skies in the afternoon will likely bring 1 or 2 degrees of warming to most areas.
There will be no wind issues during the 3 day period, just the typical locally gusty northerly winds across the western Santa Ynez range.
(Sun-Wed), 20/306 AM.
Pretty benign weather is forecast for the xtnd period. Srn CA will be sandwiched between SW flow to the northwest and SSE to the SE. The current forecast shows only minor day to day variations in temperatures. Max temps will mostly run 2 to 4 degrees above normal. The one caveat is that the EC bring neutral flow in the E/W direction and actual offshore flow from the north during the Tue/Wed period. If this develops max temps will come in much warmer than currently fcst for some areas.
The morning low cloud pattern will be similar to the short term with good confidence that the Central Coast will see plenty of morning low clouds. Lower confidence for areas south of Pt Conception with low cloud development pretty dependent on whether an eddy spins up or not.
The area will be on the fringe of the monsoon transport through the period. It is most likely the the convection will stay to the south and east of LA county with only a 5 to 10 percent chc of it reaching LA county on any given afternoon.
20/1006z.
At 0832Z at KLAX, the marine layer was 800 feet deep. The top of the inversion was at 2900 feet with a temperature of 29 C.
High confidence in VFR TAFs for KPMD, KWJF, KPRB, KBUR, and KVNY.
Good confidence in TAF for KSBP, KSMX, KOXR and KCMA as timing of flight cat changes may be off +/- 2 hours of forecast. Cig height may be off +/- 200 feet.
Fair confidence in TAF for KSBA with a 20 percent chc of IFR conds 13Z-17Z.
Low confidence in TAFs for and KSMO with a 40 percent chc of IFR conds 11Z-17Z.
Low confidence in TAFs for KLAX and KLGB with a 40 percent chc of no low clouds.
All LA county sites have a 15-20 percent chc of a TSTM
KLAX, Low confidence in TAF through 17Z and again aft 21/05Z with good confidence in between. There is a 40% chance of no low clouds. Any east wind component is expected to remain below 8 kt.
KBUR, High confidence in CAVU TAF. No wind issues expected.
20/307 AM.
Moderate confidence in periods of Small Craft Advisory (SCA) level winds (20-30 knots) across the Outer Waters each afternoon and evening into next week, with lowest chances Thursday (40-60% chance of SCAs to be issued). Local gusts of 20-25 kt will be possible across the nearshore waters along the Central Coast through tomorrow, then a moderate chance for more widespread wind gusts reaching 25 knots Friday-Sunday.
Aside from gusts of 20-25 knots reaching the western half of the Santa Barbara Channel this evening, and again each afternoon and evening over the weekend, widespread SCA conditions are not likely across the nearshore waters south of Point Conception. Localized gusts near 20 knots are possible near Point Dume and the San Pedro Channel at times.
Ca, Heat Advisory in effect until 8 PM PDT this evening for zones 38-88-343>345-351-353-371>373-375-376-379-380-548. (See LAXNPWLOX). PZ, NONE.
