textproduct: Los Angeles

SYNOPSIS

21/825 PM.

A shallower marine layer is expected over the next few days and a significant warming trend will start Monday, peaking around Wednesday with well above normal afternoon temperatures. A push of moisture midweek will bring at least a low chance for rain and then drier conditions return. Temperatures are expected to cool heading into the end of the week and the weekend.

LONG TERM (THU-SUN)

22/148 AM.

For the extended period, models continue to exhibit good synoptic agreement. At upper levels, trough will sag across the state with cyclonic flow over the area through the weekend. At the surface, moderate onshore flow will continue with some enhancement of northerly offshore gradients next weekend.

Forecast-wise, no dramatic changes to current forecast thinking. On Thursday, the heat will have one last hurrah across the area, although it will be a couple degrees cooler than Wednesday. So, HEAT ADVISORIES for LA county will remain in effect through Thursday evening.

For Friday through Sunday, the cyclonic flow aloft will usher in a cooling trend for all areas with lowering thicknesses and increased areal coverage of marine layer stratus. Typical onshore winds will continue across interior sections each afternoon and evening. However, with the increase in northerly offshore gradients, there will be an increase in northerly winds across the Santa Ynez Range and the I-5 Corridor. Winds across the western half of the Santa Ynez Range could approach advisory levels next weekend.

AVIATION

22/1722Z.

At 1610Z at KLAX, the marine layer was 2000 feet deep. The top of the inversion was 3400 feet with a temperature of 17 C.

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

For all other sites, low to moderate confidence in 18Z TAFs. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums by one category.

There is a 50% chance of LIFR CIGs at KPRB from 23/10-15Z.

KLAX...Moderate confidence in TAF. Timing of flight category changes could be +/- 2 hours of current forecasts. No significant east wind component is expected.

KBUR...Moderate confidence in TAF. VFR conditions expected. However, there is a 10% chance of CIG/VSBY restrictions from 23/08-15Z.

MARINE

22/818 AM.

High confidence in winds and seas remaining below Small Craft Advisory (SCA) levels through Wednesday. Local gusts could reach 21 kts near Point Conception in the evening. Moderate chances for SCA conditions return to the Outer Waters Thursday afternoon/evening persisting into the weekend. These conditions could reach into the nearshore waters along the Central Coast and the Santa Barbara Channel at times. Main concern is wind although seas could approach SCA levels later into the weekend.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory remains in effect from 8 AM Tuesday to 9 PM PDT Thursday for zones 88-368-372-373-379-380-548. (See LAXNPWLOX). PZ...NONE.