textproduct: Los Angeles

SYNOPSIS

21/357 AM.

Night through morning marine layer clouds will be confined to the coastal areas, mainly along the Central Coast, through much of this week. Warm conditions are expected away from the immediate coast. Slight cooling is forecast today with increased humidity.

LONG TERM (MON-THU)

21/352 AM.

For the extended, a rather stagnant pattern is expected. At upper levels, southwestern California remains on the western edge of the high pressure, which shifts slightly from centered over the Texas New Mexico border to the Arizona New Mexico border. Not seeing significant changes in day to day heights, so warm weather should persist. The onshore LAX-DAG pressure gradient continues to trend weaker through Tuesday, but is forecast to strengthen somewhat mid-week.

Forecast-wise, only minor day-to-day changes are expected in the sensible weather. There will be some warming Tuesday-Wednesday, so, areas away from the coast will generally remain 5-10 degrees above seasonal normals. Depending on how things develop, there is a chance of some heat products being needed next week. There is a significant spread in the model gradients, so confidence is lower in terms of the strength of the onshore flow. If the ECMWF is correct with the weak diurnal pressure gradients, then high temperatures could be warmer than currently forecast.

As for winds, there will continue to be some weak northerly offshore gradients. So, continued northerly Sundowner winds can be expected across southern Santa Barbara county each night, mainly around the Gaviota and Refugio areas. Tuesday evening currently has the best chance for wind advisories, but cannot rule out Monday or Wednesday evenings as well.

As for clouds and precipitation chances, the area will remain on the periphery of any monsoonal moisture. Upper level flow is forecast to shift more southwesterly as early as Saturday, so, any convection will likely remain south and east of the district, but there will still be a 5-10% chance of afternoon convection over the mountains. The marine layer will likely continue to be patchy in areal coverage (especially south of Point Conception), but many coastal areas will continue to deal with night/morning stratus and fog.

AVIATION

21/1244Z.

At 0353Z at KLAX, there was no marine layer. The top of the inversion was at 3100 feet with a temperature of 29 C.

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

Moderate confidence in KSBP and KSMX due to uncertainty in cig heights and visibility. Low confidence in KOXR and KCMA with a 40% chance of no low clouds, or CIGs that appear for a short time. If CIGs occur, LIFR/IFR conds are most likely.

Low to moderate confidence for the LA Coastal sites with a 30% chance of no low clouds, or periodic/short lived CIGs. If CIGs occur, cig heights and vis may be off one category.

There is a 20-30% chance of -SHRA at KPMD and KWJF from through 18Z.

KLAX...Low to moderate confidence in the 12Z TAF. Brief cigs are possible, with an early clearing time. There is a 30% chance of no low clouds.

KBUR...High confidence in TAF.

MARINE

21/324 AM.

Moderate to high confidence in periods of Small Craft Advisory (SCA) level winds (20-30 knots) across the Outer Waters each afternoon and evening into next week, thus a long duration SCA has been issued through Sunday morning. This may need to be extended into next week as we progress through the weekend. Gusts of 20-25 kt will be possible across the nearshore waters along the Central Coast through this evening, then there is a moderate chance for more widespread wind gusts reaching 25 knots starting Saturday.

Aside from gusts of 20-25 knots reaching the western half of the Santa Barbara Channel each afternoon/evening starting today, widespread SCA conditions are not likely across the nearshore waters south of Point Conception. Localized gusts near 20 knots are possible near Point Dume and the San Pedro Channel during the afternoon through early evening hours starting today. Winds may pick up in strength a bit early next week, with low to moderate chances that conditions become widespread enough to warrant an advisory.

LOX WATCHES/WARNINGS/ADVISORIES

CA...NONE. PZ...Small Craft Advisory in effect from noon today to 2 AM PDT Saturday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Sunday for zones 670-673-676. (See LAXMWWLOX).