textproduct: Los Angeles

SYNOPSIS

01/259 AM.

Steady cooling trend through Monday with some low clouds and dense fog developing. Gusty west to north winds will form this afternoon and continue through early Tuesday. Widespread moderate to locally strong winds northwest to northeast likely Wednesday through Saturday, with possible showers over the mountains.

LONG TERM (WED-SAT)

01/259 AM.

Although the synoptic picture remains fairly complex, there is much better agreement now between the EC and the GFS. A trough will swing into the West Coast on Wednesday, moving east into the Great Basin by Thursday. After stalling over the Western CONUS, the trough begins to detach itself from the main upper level flow, cutting off and swinging to the southwest into SoCal late Friday into Saturday. Northerly winds will begin to increase and become widespread through the day on Wednesday, with advisory level winds looking likely at this point, especially across higher elevations. There is even a low risk for high elevation warning level winds late Wednesday into Thursday.

Northerly winds will strengthen come Friday as the upper low detaches and moves across SoCal. Winds will peak sometime Friday through Saturday as upper level support lines up well with the surface level winds, allowing for winds to mix down to the surface. While widespread advisory level winds appear likely at this pointeven at low elevations, higher terrain areas are at risk for damaging, warning level winds.

This system is quite moisture starved (PWATs less than inch), so any significant precipitation looks highly unlikely at this point. However, PWATs are forecast to increase to around of an inch late next weekend into the early second week of March as the upper low siphons some moisture from the south. Still, however, most ensemble members are dry or show very inconsequential precip totals.

Their AI counterparts have pretty solid agreement with each other, but they both differ slightly from the non AI versions. In this case, the AI models keep the low more to the south and east, which would result in weaker winds. Time will tell whether the legacy or new-age models perform better in this scenario.

AVIATION

01/1759Z.

At 1651Z at KLAX, there was no marine layer. There was a surfaced based inversion with a top at 2200 ft and a temperature of 22 C.

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

Moderate to low confidence in remaining TAFs. Timing of CIG/VSBY restrictions may be off +/- 3 hours and flight minimums off by one or two categories.

KLAX...Fair confidence in CIG forecast. Arrival and Clearing times of LIFR to IFR (003-007) may be off +/- 3 hours, with a 30% chance CIGs do not develop. High confidence in wind forecast with no significant east wind component expected.

KBUR...VFR conditions are expected through the period, except for a 20% chance of V/LIFR conditions from 02/10 to 02/17Z. No wind impacts are expected at this time.

MARINE

01/827 AM.

For the Outer waters, Small Craft Advisory (SCA) level NW winds will continue across the waters south of Point Conception through Monday. These winds will increase in coverage and speed. Local gusts to GALE force (35 kts) is possible Monday afternoon/eve near the Channel Islands. The axis of strongest winds will shift westward and expand to the north during this time frame. Resulting in low- end SCA winds across northern waters. SCA level NW winds of 20-30 kts will be common across all Outer Waters by Tuesday evening. Winds will become strongest Wednesday morning through late Thursday night, especially during the afternoon/eve hours. During this period, there is a 60% chance of GALES and 30% chance for the nearshore waters along the Central Coast. There is a non- zero chance for Storm Force winds, but more likely outcome would be moderate to high end GALES. SCA winds will likely linger through the weekend. SCA seas expected Wednesday through possibly Saturday morning.

For the inner waters south of Point Conception, SCA level W winds up to 25 kt expected across the Santa Barbara Channel this afternoon. By the evening, these winds will expand to include much of the waters adjacent to the Los Angeles and Orange Counties. Winds will increase on Monday, especially across the SB Channel where there is a 50-60% chance of low-end GALES during the afternoon/eve hours focused near the Channel Islands. Tuesday looks to be the calmest day where winds could drop below SCA levels for much of the waters excluding western portion of the SB Channel. Wednesday afternoon through Friday morning SCA winds are likely across the SB Channel. There is a moderate chance (40%) of Wednesday afternoon/eve across western portion of the SB Channel. Offshore flow tilts more from the east starting Friday thus waters typically impacted by Santa Ana Winds will need to keep in mind for more SCA winds potential into Weekend.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory now in effect from 6 PM this evening to 3 AM PST Tuesday for zones 349-351. (See LAXNPWLOX). PZ...Small Craft Advisory in effect from noon Monday to 3 AM PST Tuesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 PM PST Monday for zones 650-673-676. (See LAXMWWLOX). Gale Watch in effect from Monday afternoon through late Monday night for zones 650-673-676. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PST Tuesday for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM Monday to 3 AM PST Tuesday for zone 670. (See LAXMWWLOX).