textproduct: Los Angeles

SYNOPSIS

08/104 AM.

Night through morning low clouds and patchy dense fog will be common over coastal areas and the coastal valleys through the weekend. Over the interior areas, hazardous heat will continue through this weekend and expand into the coastal valleys, with near to above normal temperatures around the beaches. Other than a small chance for mountain showers during the afternoon and evening hours through Sunday, dry conditions will prevail.

LONG TERM (TUE-FRI)

08/235 AM.

Very little change in the long term forecast compared to yesterday. 500 mb heights will continue to drop to at least 592 dam through Friday, and maybe even lower. At the same time, onshore flow will increase both to the north and the east becoming strongly onshore in both directions in the afternoons. The marine layer will respond to this and low clouds will likely begin to extend into the valleys. Look for slower than normal clearing and some west facing beaches may see only limited clearing each afternoon and evening.

The combination of a deeper marine layer, stronger onshore flow, and falling heights will bring 2 to 3 degrees of cooling each day through Thursday. Maximum temps will largely be below normal by Tuesday, and by Wednesday, valley temps will be in the 80s with maybe a few degrees of 90s. In other words, finally a "cooler" period of time this summer.

PWs will remain elevated through the period, however. In combination with warmer than normal ocean temperatures off the immediate coast, conditions will continue to feel a little more humid than normal. It will also keep overnight lows a little warmer than normal. The region will remain on the fringe of the monsoonal moisture through at least Wednesday, with the elevated moisture and increased instability keeping the low chance (10 to 15 percent) of afternoon mountain convection going. By the end of next week, medium-range model guidance indicates the potential for an upper low to develop off the Central California Coast, east of which large-scale ascent and convective chances could modestly increase next Thursday and Friday.

Additionally, the strong onshore flow to the east will produce near advisory level wind gusts across the western Antelope Valley and the western foothills each afternoon and evening. Gusty sundowner winds will also be possible early next week in southern Santa Barbara County.

AVIATION

08/1746Z.

At 1639Z at KLAX, the marine layer was 800 feet deep. The top of the inversion was at 3600 feet with a temperature of 27 C.

High confidence in VFR TAFs for KPRB, KBUR, KVNY, KPMD & KWJF.

Low to moderate confidence in remaining TAFs due to uncertainties in coverage and timing of low clouds and LIFR/IFR conds tonight into Sun morning. Some mid-level moisture and warm sea surface temps will disrupt the formation of marine layer. This will likely result in intermittent CIGs especially for KLAX, KSMO, & KLGB. CIG heights accurate within +/- 200 ft of current forecast.

KLAX...Fair confidence in TAF. Intermittent CIGs (007-010) possible 03Z-15Z Sun. No significant east wind component expected.

KBUR...High confidence in VFR TAF. No wind issues expected.

MARINE

08/819 AM.

Winds and seas are expected to remain largely below Small Craft Advisory (SCA) criteria across the coastal waters through Wednesday night. However, northwest winds locally gusting to 20-25 knots in typically windy areas around and to the south of Point Conception can be expected each afternoon and evening through Sunday.

Dense fog may affect portions of the coastal waters each night through morning this weekend and possibly into early next week.

BEACHES

08/819 AM.

High astronomical tides are expected to affect low-lying beaches south of Point Conception with the possibility of minor coastal flooding starting with the evening high tide Monday and continuing through at least Wednesday.

Predicted tide heights of up to 7.5 feet are expected between about 8 and 10 PM each evening. These tides, combined with an increase in a long-period southerly swell, could result in minor flooding of sea water around the time of high tide over low-lying coastal areas such as parking lots, beaches, and walkways. Beaches most susceptible to potential minor coastal flooding issues include those around Point Dume and near Long Beach.

LOX WATCHES/WARNINGS/ADVISORIES

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 88-342>345-348-349-351>353-356>358-367>376-378>380-548. (See LAXNPWLOX). PZ...NONE.