05/1201 AM.
Seasonably warm weather will continue away from the immediate coast, while far interior areas will continue to bake under triple digit temperatures all week. Along the coast low clouds and locally dense fog will develop and could linger into the afternoon in some areas.
(tdy-Fri), 05/938 AM.
***UPDATE***
The forecast is well on-track, and no changes have been made to the ongoing forecast.
***From Previous Discussion***
Not much synoptic change at all over the next three days a 595 dam upper high will sit over AZ with 594-595 dam hgts over Srn CA. There will be mdt-stg onshore flow to the east and weak-mdt onshore flow to the north.
The marine layer will be near 1400 ft and night through morning low clouds and fog will affect not only the csts but also some of the lower coastal vlys each day. Some nearshore areas will see slow clearing in the afternoon due to the strong onshore to the east.
There will be a slow warming trend through the period and by Friday most max temps will be 4 to 8 degrees over normal. Lower confidence in the warming trend for the coasts and the onshore flow and marine layer could easily defeat any other warming effects. While all areas will have above normal temps only the interior sections will be warm enough to support heat warnings and advisories, which run through the period and into the xtnd periods as well.
One more thing will be the increase in humidity as monsoon moisture move in under the upper high and into Srn CA. The increased humidities will make the daytime highs feel worse and will hinder the overnight cooling. It will produce a non zero chc of afternoon convection over the mtns, but still too low to mentioning the fcst.
The strong onshore flow in the afternoon will produce stronger than normal sea breezes and gusty afternoon winds in the interior. The gusty winds in the interior in combination with the hot and dry conditions will produce elevated fire weather conditions.
(Sat-Tue), 05/232 AM.
The pattern will remain the same Saturday and Sunday. Max temps will remain 4 to 8 degrees above normal, min temps will remain 3 to 6 degrees above normal and humidities will also be above normal. This will continue the dangerous heat effects and Heat warnings (and very likely heat advisories for many non coastal areas) are currently in effect through Saturday evening with a 40 percent chc of an extension into Sunday.
The area will continue to be on the western edge of the monsoon with a 5-10 percent chance of showers or thunderstorms again focused across interior Los Angeles County mountains and deserts.
The ridge begins to break down on Monday and continues into Tuesday. This should lead to 2 days of cooling and an elimination of the need for heat products.
05/1907z.
At 1900Z at KLAX, the marine layer was 1600 feet deep. The top of the inversion was near 5800 feet with a temp of 25 C.
High confidence in VFR conds for KPMD and KWJF.
Good confidence in TAFs for KPRB, KBUR, and KVNY with a 15 to 20 percent chc of IFR cigs 13Z-15Z.
Moderate confidence in the remainder of the TAFs where cigs could be off by +/- 200 ft. VFR conds could arrive up to 90 minutes later than fcst.
KLAX, Moderate confidence in TAF. There is a 30 percent chc that cigs remain AOA 010. VFR transition could be as late as 1930Z Thursday. No significant east wind component expected.
KBUR, High confidence in TAF. There is only a 15 percent chc of BKN006 conds 13Z-16Z.
05/237 AM.
Winds and seas are expected to remain below Small Craft Advisory (SCA) criteria through the week, with the exception of northwest winds locally gusting to 20-25 knots in typically windy areas around and to the south of Point Conception each afternoon and evening.
Dense fog may affect portions of the coastal waters each night through morning through much of the week, especially across the waters north and west of Point Conception.
Ca, Extreme Heat Warning in effect until 8 PM PDT Sunday for zones 38-377-381>383. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT Sunday for zones 344-345-353-375-376-378>380. (See LAXNPWLOX). PZ, NONE.
