textproduct: Los Angeles

SYNOPSIS

21/240 AM.

A weak upper level trough will move over the area today, cooling temperatures and increasing marine layer stratus. A warming trend will begin Tuesday and peak on Wednesday, with highs 5 to 10 degrees above normal.

LONG TERM (THU-SUN)

21/241 AM.

Broad troffing will likely cover the state later this week and into the weekend. The GFS does favor a ridge on Sunday but the EC, the EC-AI and many ensembles show the trof hanging on to the coast.

The onshore gradients will be fairly week through the period and there will be some weak offshore flow from the north during the mornings. This and the fact the troffing is not very sharp or dynamic will likely result in only a patchy marine layer stratus pattern.

Max temps will cool a little on most of the days, but most temps will remain a few degrees above normal. Blended ensemble guidance shows 4 to 8 degrees of cooling on Sunday, but this may be over done given the 586 fcst hgts and offshore flow from the north in the morning.

AVIATION

21/1732Z.

At 1659Z at KLAX, the marine layer was 4400 ft deep. The top of the inversion was at 6800 ft with a temperature of 14 C.

High confidence in VFR conds for KPMD & KWJF.

Low to moderate confidence in the remaining sites. There is a 40% chance for no clearing today at KSBP/KSMX, with a 10% chance at LA County sites until after 00Z. Arrival of cigs tonight may be off by 3 hours, and confidence is low in min cig heights, where TAFs may be off my one category. There is a chance for no cigs tonight at KOXR/KCMA (40%), KBUR/KVNY (30%), KLAX/KLGB/KSMO (20%). There is a 20% chance for brief IFR-MVFR cigs at KSBA after 12Z.

KLAX...Moderate confidence in TAF. BKN040+ cigs may linger through 22Z, with a 10% chance for no clearing until after 00Z. Low confidence in return timing (+/- 3 hours) and min cig height (015-025). There is a 20% chance for no low clouds tonight. Any east wind component is expected remain less than 6kt.

KBUR...Moderate confidence in TAF. BKN035+ cigs may linger through 22Z, with a 10% chance for no clearing until after 00Z. Low confidence in return timing (+/- 3 hours) and min cig height (008-015). There is a 30% chance for no low clouds tonight.

MARINE

21/845 AM.

Good confidence in Small Craft Advisory (SCA) west to northwest winds across the outer waters south and west of Point Sal and through the Santa Barbara Channel this afternoon through tonight. SCA winds are expected to become more widespread tomorrow afternoon into early Wednesday, including across the nearshore Central Coast waters. Winds are expected to decrease some Wednesday, then SCA northwest winds will likely return across the outer waters, nearshore central coast waters, and potentially the Santa Barbara Channel as early as late Thursday into the weekend.

LOX WATCHES/WARNINGS/ADVISORIES

CA...NONE. PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 5 AM PDT Tuesday for zones 673-676. (See LAXMWWLOX).