textproduct: Los Angeles

SYNOPSIS

17/1213 PM.

Night through morning marine layer clouds will be confined to the coastal areas through much of this week. Warmer and drier conditions are expected away from the immediate coast, with peak heat likely being Tuesday through Thursday when moderate heat risk is expected in warmest locations.

LONG TERM (FRI-MON)

17/136 PM.

There will be a little bit of cooling on Friday mostly due to an increase in mid and high level clouds. Still, max temps will remain well above normal, and like mentioned in the short term discussion, there is a small chance of heat advisories needing to be extended for portions of the area.

The upper high is forecast to migrate to the four corners area by Thursday night, 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 be nudged a little to the east over the weekend as a weak trof moves through the PACNW and the northern half of CA. The weak lift from the trof may bring a little better low cloud development, although this is far from certain. Look for 1 to 2 degrees of cooling each day - maybe a little more for SLO county due to the proximity to the trof. The cooling will bring most areas north of Pt Conception down to near or below normal temps. South of Pt Conception, however, most max temps will remain a few degrees above normal.

AVIATION

17/1645Z.

At 1630Z at KLAX, the marine layer was 900 feet deep. The top of the inversion was 3100 feet with a temperature of 24 degrees Celsius.

For 18Z TAF package, high confidence in KBUR, KVNY, KPMD and KWJF.

For all other sites, moderate confidence in 18Z TAFs. Forecast timing of return of CIG/VSBY restrictions could be +/- 2 hours of current forecasts. Other sites that are VFR have a 30-40% chance of getting CIG/VSBY restrictions 08Z-17Z.

KLAX...Moderate confidence in 18Z TAF. There is a 40% chance of IFR conditions 08Z-17Z. No significant easterly wind component is expected.

KBUR...High confidence in 18Z TAF with VFR conditions expected through the period.

MARINE

17/1207 PM.

For the Outer Waters, high confidence in current forecast. Today through Saturday, Small Craft Advisory (SCA) level winds can be expected. Building short-period seas can be expected across the Outer Waters, rising to the 6-9 foot range.

For the Inner Waters north of Point Sal, moderate confidence in current forecast. Today through Wednesday, there is a 30-40% chance of SCA level winds in the afternoon and evening hours. For Thursday through Saturday, 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 60-80% chance of SCA level winds tonight through Tuesday night...then a 30-40% chance of SCA level winds Wednesday through Saturday. Elsewhere south of Point Conception, high confidence in winds and seas remaining below SCA levels today through Saturday.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory in effect from 10 AM Tuesday to 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 Tuesday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX).