textproduct: Los Angeles

SYNOPSIS

28/225 AM.

Gradual cooling will continue through the week as will coastal flooding issues due to very high tides. The next storm system is expected to arrive late Friday or Saturday with rain chances continuing into Sunday.

LONG TERM (SAT-TUE)

28/214 AM.

The weekend storm forecast still remains a the tricky side. This system is more of a slug of moisture moving into and over the area rather an organized front or low pressure system. And since all of the moisture is over the data sparse eastern Pacific there is a good chance that the initial conditions for the forecast mdls are less than perfect. Right now the best moisture assoc with the plume is forecast to move in south of LA county. There is still quite a bit of disagreement on how wet the plume will be. One thing is becoming more clear - the best dynamics will occur Saturday evening as a trof assoc with the upper low moving through the PACNW will move through Srn CA. NVA follow close on the heels of this trof and the chc of rain will diminish quickly from w to e later Sunday morning. The most likely rainfall totals for this system south of Pt Conception are about a third to a half inch with double those amounts across some south facing slopes. Less than quarter inch is forecast for areas north of Pt Conception. There is only moderate confidence in these numbers as some solutions show quite a bit more rainfall and some even less. Shorter range hier rez mdls will begin to forecast this storm later today and this may provide more clarity.

Due to the SW origin of the moisture plume snow will not be an issue and will only fall above 9000 ft. Max temps will only be in the 60s on Saturday with some warming into the upper 60s and lower 70s Sunday as there will likely be some sunshine in the afternoon.

As is so often the case with trof passages upper level ridging and offshore flow will develop. It does not look like there will be advisory level winds but skies will be mostly clear and max temps will rise 4 to 5 degrees on Monday and maybe a degree or 2 on Tuesday. Longer range mdls are showing the chc of a weak system arriving next Wednesday.

AVIATION

28/1703Z.

At 1600Z at KLAX, the marine layer was 3600 ft deep. The top of the inversion was at 5700 ft with a temperature of 14 C.

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

Moderate confidence in remaining TAFs. SCT-OVC250 with chc for VFR CIGs 030-50. MVFR CIGs 025-030 possible especially earlier in fcst.

KLAX...Moderate confidence in TAF. SCT/BKN035-055 likely after 29/06Z. Any east wind component is expected to remain under 8 kt.

KBUR...Moderate confidence in TAF. SCT/BKN 030 possible after 29/06Z. No wind issues expected.

MARINE

28/802 AM.

Conditions are expected to remain below Small Craft Advisory (SCA) levels through Friday. Southwest flow aloft will produce chances for drizzle and isolated light rain showers Thursday and Friday.

A storm system is expected to impact the coastal waters this weekend. There is a wide range of outcomes, but there is at least a low threat of a 12-24 hour period of strong winds and steep seas. Worst conditions look to be focused south of Pt Conception.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory in effect until 1 PM PDT Thursday for zones 87-340-346-349-350-354-362-366. (See LAXCFWLOX). PZ...NONE.