textproduct: Los Angeles

SYNOPSIS

12/1031 AM.

A cooling trend will continue through Thursday, with cooler than normal temperatures expected across the area into the weekend. There is a chance of mountain and occasional lower elevation convection through at least tonight and potentially lingering into Thursday morning. More robust marine layer cloud coverage is likely this week, however, higher clouds may disrupt the formation of the marine layer at times.

LONG TERM (SUN-WED)

12/301 PM.

Good agreement with all of the medium range models. The trough will be pushed to the west by a powerful upper high that spans most of the southern portion of the CONUS. 500mb heights will climb to 592 dam, with dry SW flow aloft. At the surface, Onshore flow will weaken, with the push to the east weakening slightly, but the push to the north weakening substantially. Surface flow might might even be offshore by Tuesday or Wednesday.

The weather will be benign through the period. There will be plenty of night through morning low clouds and fog across the coasts. Due to the rising heights, the marine layer will shrink to under a 1000 ft which should keep it out of the valleys. Skies, otherwise, will be mostly clear. The weakening onshore flow to the north will also lessen the amount of coastal low clouds early next week, especially if the offshore flow develops.

Gusty but still sub-advisory levels winds will continue across the Antelope Valley.

Temperatures will continue to warm each day, though still remain below normal through the extended.

AVIATION

12/1736Z.

At 1639Z at KLAX, the marine layer was 1600 feet deep. The top of the inversion was near 2500 feet with a temperature of 21 C.

High confidence in TAFs for desert airfields (KPMD & KWJF).

Moderate confidence in remaining TAFs. Timing of prevailing groups may be off +/- 2 hours and conditions by one category.

KLAX...Moderate confidence in TAF. Arrival and clearing of MVFR CIGs (012-018) may be off +/- 2 hours. No significant east wind component expected.

KBUR...Moderate confidence in TAF. No wind issues expected.

MARINE

12/815 AM.

High confidence that conditions will remain below Small Craft Advisory (SCA) criteria across all coastal waters through Friday morning. Low to moderate chances for SCA winds across favored areas south of Point Conception this weekend. Increasing chances across all coastal waters heading into next week.

There is a slight chance of a shower or a thunderstorm around and north of Point Conception later this afternoon thru early Thursday morning.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory in effect until midnight PDT tonight for zones 349-350-354-362-366. (See LAXCFWLOX). PZ...NONE.