textproduct: Los Angeles

SYNOPSIS

18/723 AM.

Night through morning marine layer clouds will be confined to the coastal areas, mostly north of Pt Conception, through much of this week. Warmer and drier conditions are expected away from the immediate coast, with the heat peaking today through Thursday, when moderate heat risk is expected in warmest locations.

LONG TERM (SAT-TUE)

18/236 PM.

All medium range models agree that the upper high will shift to the four corners area by Friday, which will set up SE monsoon flow over Southern CA. This SE flow will allow Precipitable Water values to approach 1.5" across southern L.A. County starting Friday afternoon. This influx of moisture will allow for a 5-10 percent chance of showers or thunderstorms to to develop over the LA County mountains and Antelope Valley Friday afternoon through the weekend.

The upper high will shift slowly eastward Saturday through Monday and hgts will fall to 592 dam on Saturday and about 590 dam by <onday. The onshore gradients do not change much so the pattern of plenty of morning low clouds over the Central Coast and minimal low clouds for areas south of Pt Conception should continue. 1 to 2 degrees of cooling each day should bring most max temps down to a few degrees under normal by early next week.

AVIATION

18/2321Z.

At 2238Z at KLAX, the marine layer was 900 feet deep. The top of the inversion was at 1900 feet with a temperature of 29 C.

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

For KSBP & KSMX, timing of flight category changes could be +/- 2 hours of current forecast.

(Late tonight through early tomorrow morning) Chances for IFR conditions: KOXR/KCMA/KSMO/KLAX (20%), KLGB (30%).

KLAX...Moderate confidence in TAF. There is a 30% chance of IFR conditions 10Z-17Z. No significant easterly wind component is expected.

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

MARINE

18/1209 PM.

For the Outer Waters, high confidence in current forecast. Small Craft Advisory (SCA) level winds are expected today through Sunday.

For the Inner Waters north of Point Sal, moderate confidence in current forecast. Through Thursday, there is a 30-40% chance of SCA level winds in the afternoon and evening hours. For Friday through Sunday, there is a 50-70% chance of SCA level winds in the afternoon and evening hours.

For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For the western half of the Santa Barbara Channel, there is a 60% chance of SCA level winds late this afternoon and tonight. For Wednesday through Sunday, there is a 30-40% chance of SCA level winds during the afternoon to evening hours. Elsewhere south of Point Conception, high confidence in winds and seas remaining below SCA levels through Saturday.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory in effect until 8 PM PDT Thursday for zones 38-88-343>345-351-353-371>373-375-376-379-380-548. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 670-673-676. (See LAXMWWLOX).