textproduct: Los Angeles

SYNOPSIS

16/1053 PM.

Generally quiet weather expected with cooler than normal temperatures and a robust marine layer today. Slight warming and a shrinking marine layer are expected Friday into the weekend.

LONG TERM (SUN-WED)

16/1228 PM.

Quiet weather continues Sunday and most likely through the extended period. A weak upper level low will swing into the area Sunday, most likely remaining overhead through Monday and potentially Tuesday. While the most likely outcome is generally slightly cooler temps with a deeper and more expansive marine layer and the potential for morning drizzle, there is a very small chance for isolated shower or thunderstorm activity (likely focused over the interior mountains). Most European ensemble members show increasing PWATs as the upper low's cyclonic flow attempts to pull in some moisture from the fetch to our south and east, but PWAT values are not very substantial with a mean just over 1". Additionally most members also show some increasing CAPE over the area. However QPF output is very limited to nil, so it appears that the still limited moisture and the weakness of the trough will limit any sort of convective initiation. We will continue to monitor this very low chance for some "exciting" weather in an otherwise quiet pattern.

For Tuesday-Wednesday the most likely outcome is for that upper low to be replaced by weak ridging with slightly increasing 500 mb heights and weakening onshore flow, resulting in region-wide warming. There does remain a very low chance for that mountain focused convective activity continues.

AVIATION

17/0553Z.

At 0508Z at KLAX, the marine layer was 3300 feet deep. The top of the inversion was at 6500 feet with a temperature of 17 C.

High confidence in TAFs for KPMD and KWJF.

Moderate in remaining TAFs. Cigs may vary between 025 and 035. Low VFR cigs may not scatter out until 18/00Z.

KLAX...Moderate confidence in TAF. Cigs may vary between 025 and 035 through 20Z. BKN035 conds may persist through 00Z. There is a 15% chance of an east wind component of 6-8 kts 09Z-16Z.

KBUR...Moderate confidence in TAF. Cigs may vary between 025 and 035 through 20Z. BKN035 conds may persist through 00Z.

MARINE

16/910 PM.

For the outer waters, moderate to high confidence in the current forecast. Winds and seas will remain below Small Craft Advisory (SCA) levels through this afternoon. Winds are likely to increase to SCA levels tonight and continue through Monday night, most prevalent and long-lasting for the waters west and south of Point Conception. Expect steep, choppy seas with the SCA conditions.

For the inner waters N of Point Sal, generally high confidence in the current forecast. Conds are expected to be below SCA levels through Friday morning, then SCA wind gusts are likely during the afternoons and evenings from Friday through Sunday.

For the inner waters S of Point Conception, moderate confidence in the current forecast. Conds are expected to be below SCA levels for the most part through Monday night. However, for the western Santa Barbara Channel, there is a 60% chance of SCA wind gusts Friday evening, a 50% chance of these gusts Monday evening, and a 30% chance of these gusts Saturday evening and Sunday evening.

LOX WATCHES/WARNINGS/ADVISORIES

CA...NONE. PZ...Small Craft Advisory in effect from 3 PM Thursday to 3 AM PDT Saturday for zones 673-676. (See LAXMWWLOX).